Author: "Institut National des Sciences Appliquées (INSA)" / Journal: journal of applied physics - Searchworks@Jio Institute Digital Library Search Results

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129 results on '"Institut National des Sciences Appliquées (INSA)"'

1. Macroscopic and nanoscale electrical properties of pulsed laser deposited (100) epitaxial lead-free Na0.5Bi0.5TiO3 thin films

Author: Science des Procédés Céramiques et de Traitements de Surface (SPCTS) ; Université de Limoges - Ecole Nationale Supérieure de Céramique Industrielle - Institut des Procédés Appliqués aux Matériaux - CNRS, Axe 3 : organisation structurale multiéchelle des matériaux ; Science des Procédés Céramiques et de Traitements de Surface (SPCTS) ; Université de Limoges - Ecole Nationale Supérieure de Céramique Industrielle - Institut des Procédés Appliqués aux Matériaux - CNRS - Université de Limoges - Ecole Nationale Supérieure de Céramique Industrielle - Institut des Procédés Appliqués aux Matériaux - CNRS - Faculté des Sciences et Techniques ; Université de Limoges - Science des Procédés Céramiques et de Traitements de Surface (SPCTS) ; Université de Limoges - Ecole Nationale Supérieure de Céramique Industrielle - Institut des Procédés Appliqués aux Matériaux - CNRS - CNRS, Axe 2 : procédés de traitements de surface ; Science des Procédés Céramiques et de Traitements de Surface (SPCTS) ; Université de Limoges - Ecole Nationale Supérieure de Céramique Industrielle - Institut des Procédés Appliqués aux Matériaux - CNRS - Université de Limoges - Ecole Nationale Supérieure de Céramique Industrielle - Institut des Procédés Appliqués aux Matériaux - CNRS - Science des Procédés Céramiques et de Traitements de Surface (SPCTS) ; Université de Limoges - Ecole Nationale Supérieure de Céramique Industrielle - Institut des Procédés Appliqués aux Matériaux - CNRS - CNRS, Axe 3 : organisation structurale multiéchelle des matériaux ; Science des Procédés Céramiques et de Traitements de Surface (SPCTS) ; Université de Limoges - Ecole Nationale Supérieure de Céramique Industrielle - Institut des Procédés Appliqués aux Matériaux - CNRS - Université de Limoges - Ecole Nationale Supérieure de Céramique Industrielle - Institut des Procédés Appliqués aux Matériaux - CNRS - Science des Procédés Céramiques et de Traitements de Surface (SPCTS) ; Université de Limoges - Ecole Nationale Supérieure de Céramique Industrielle - Institut des Procédés Appliqués aux Matériaux - CNRS - CNRS, Center for Research in Ceramic and Composite Materials (CICECO) ; University of Aveiro, Institut des Sciences Chimiques de Rennes (ISCR) ; Ecole Nationale Supérieure de Chimie de Rennes - Institut National des Sciences Appliquées [INSA] - Université de Rennes 1 - CNRS, MINACOM ; Institut de recherche en communications optiques et microondes (IRCOM) ; CNRS - Université de Limoges - CNRS - Université de Limoges - XLIM (XLIM) ; Université de Limoges - CNRS - CNRS - XLIM (XLIM) ; Université de Limoges - CNRS - CNRS, Institut national des sciences appliquées de Lyon (INSA Lyon) ; INSA Lyon, Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM) ; CNRS - IN2P3 - Université Paris XI - Paris Sud, European Project : This work was carried out within the framework of the FAME Network of Excellence Work Package n°7, f, Bousquet, M., Duclere, Jean-René, Champeaux, Corinne, Boulle, Alexandre, Marchet, Pascal, Catherinot, Alain, Wu, A., Vilarinho, P.M., Députier, S., Guilloux-Viry, Maryline, Crunteanu, Aurelian, Gautier, B., Albertini, D., Bachelet, C., Science des Procédés Céramiques et de Traitements de Surface (SPCTS) ; Université de Limoges - Ecole Nationale Supérieure de Céramique Industrielle - Institut des Procédés Appliqués aux Matériaux - CNRS, Axe 3 : organisation structurale multiéchelle des matériaux ; Science des Procédés Céramiques et de Traitements de Surface (SPCTS) ; Université de Limoges - Ecole Nationale Supérieure de Céramique Industrielle - Institut des Procédés Appliqués aux Matériaux - CNRS - Université de Limoges - Ecole Nationale Supérieure de Céramique Industrielle - Institut des Procédés Appliqués aux Matériaux - CNRS - Faculté des Sciences et Techniques ; Université de Limoges - Science des Procédés Céramiques et de Traitements de Surface (SPCTS) ; Université de Limoges - Ecole Nationale Supérieure de Céramique Industrielle - Institut des Procédés Appliqués aux Matériaux - CNRS - CNRS, Axe 2 : procédés de traitements de surface ; Science des Procédés Céramiques et de Traitements de Surface (SPCTS) ; Université de Limoges - Ecole Nationale Supérieure de Céramique Industrielle - Institut des Procédés Appliqués aux Matériaux - CNRS - Université de Limoges - Ecole Nationale Supérieure de Céramique Industrielle - Institut des Procédés Appliqués aux Matériaux - CNRS - Science des Procédés Céramiques et de Traitements de Surface (SPCTS) ; Université de Limoges - Ecole Nationale Supérieure de Céramique Industrielle - Institut des Procédés Appliqués aux Matériaux - CNRS - CNRS, Axe 3 : organisation structurale multiéchelle des matériaux ; Science des Procédés Céramiques et de Traitements de Surface (SPCTS) ; Université de Limoges - Ecole Nationale Supérieure de Céramique Industrielle - Institut des Procédés Appliqués aux Matériaux - CNRS - Université de Limoges - Ecole Nationale Supérieure de Céramique Industrielle - Institut des Procédés Appliqués aux Matériaux - CNRS - Science des Procédés Céramiques et de Traitements de Surface (SPCTS) ; Université de Limoges - Ecole Nationale Supérieure de Céramique Industrielle - Institut des Procédés Appliqués aux Matériaux - CNRS - CNRS, Center for Research in Ceramic and Composite Materials (CICECO) ; University of Aveiro, Institut des Sciences Chimiques de Rennes (ISCR) ; Ecole Nationale Supérieure de Chimie de Rennes - Institut National des Sciences Appliquées [INSA] - Université de Rennes 1 - CNRS, MINACOM ; Institut de recherche en communications optiques et microondes (IRCOM) ; CNRS - Université de Limoges - CNRS - Université de Limoges - XLIM (XLIM) ; Université de Limoges - CNRS - CNRS - XLIM (XLIM) ; Université de Limoges - CNRS - CNRS, Institut national des sciences appliquées de Lyon (INSA Lyon) ; INSA Lyon, Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM) ; CNRS - IN2P3 - Université Paris XI - Paris Sud, European Project : This work was carried out within the framework of the FAME Network of Excellence Work Package n°7, f, Bousquet, M., Duclere, Jean-René, Champeaux, Corinne, Boulle, Alexandre, Marchet, Pascal, Catherinot, Alain, Wu, A., Vilarinho, P.M., Députier, S., Guilloux-Viry, Maryline, Crunteanu, Aurelian, Gautier, B., Albertini, D., and Bachelet, C.
Abstract: International audience, Epitaxial Na0.5Bi0.5TiO3 thin films presenting various thicknesses were grown by pulsed laser deposition on epitaxial 100 platinum bottom layers supported by 100MgO single crystal substrates. X-ray diffraction data indicated that all Na0.5Bi0.5TiO3 layers are single-phased and that 100-oriented Na0.5Bi0.5TiO3 NBT crystallites are extremely predominant. The thinner films respectively 230 and 400 nm display a quasiunique 100 orientation close to 100%, whereas for the thickest film 610 nm, the proportion of 100-oriented Na0.5Bi0.5TiO3 crystallites decreases to 85.50 vol %. Such variation is supposed to result from the degree of misorientation of the Pt layer. Further x-ray investigations revealed a pronounced asymmetry of the 100NBT reflection. Such asymmetry is also observed in the 310NBT reciprocal space maps. The analysis of the asymmetrical broadening of the reciprocal lattice point suggests a variation in the chemical composition across the samples thickness, in agreement with comparative Rutherford backscattering spectroscopy RBS data. In addition, x-ray diffraction -scans data indicate the systematic epitaxial growth of the 100-oriented crystallites. The observation of the microstructure of Na0.5Bi0.5TiO3 films completely corroborates the x-ray diffraction information. Whereas the two thinnest films are characterized by the presence of only one type of grains: i.e., very fine and spherical grains around 50-100 nm in size, the thickest film is characterized by the presence of two types of grains: the aforementioned one and some elongated and "factory roof"-like grains. Thus, we unambiguously attribute that the spherical grains correspond to 100-oriented crystallites, whereas the "factory roof"-like grains are 110-oriented. The room temperature macroscopic ferroelectric properties were measured only for the thickest film. A rather well-defined shape of the polarization-electric P-E field hysteresis loops was recorded, and a vertical drift of the loops was systemat

2. Metastable and field-induced ferroelectric response in antiferroelectric lead zirconate thin film studied by the hyperbolic law and third harmonic response

Author: Kevin Nadaud, Caroline Borderon, Raphaël Renoud, Micka Bah, Stephane Ginestar, Hartmut W. Gundel, GREMAN (matériaux, microélectronique, acoustique et nanotechnologies) (GREMAN - UMR 7347), Université de Tours (UT)-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, and Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)
Subjects: impedance spectroscopy, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], General Physics and Astronomy, domain wall, metastable, Antiferroelectric, residual ferroelectricity, hyperbolic analysis
Abstract: In this paper, the field-induced residual ferroelectricity in antiferroelectric lead zirconate thin films has been studied by impedance measurements together with a hyperbolic law analysis, which permits us to extract the different contributions to the material’s complex permittivity. By measuring the Rayleigh coefficient αr, it appears that the residual ferroelectricity is considerably enhanced when the sample has been previously exposed to an electric field close to the antiferroelectric to ferroelectric transition field. This indicates that a part of the material remains ferroelectric after the antiferroelectric–ferroelectric backward transition, which constitutes an additional contribution to polarization. Consequently, a higher domain wall density and mobility can be observed. Measurements after exposition to thermal treatment show that this ferroelectric response is metastable.
Published: 2023

3. A quantum mechanical model of field emission from a graphene blade type material

Author: Bruno Lepetit, Théorie (LCAR), Laboratoire Collisions Agrégats Réactivité (LCAR), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Fédération de recherche « Matière et interactions » (FeRMI), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), and Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS]Physics [physics], [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], General Physics and Astronomy
Abstract: We present a simple quantum perturbative full dimensionality model to study field emission from a graphene blade within the frame of the Bardeen transfer Hamiltonian formalism. The material electronic wavefunction is obtained for a multidimensional square well potential specifically designed to reproduce two important characteristics of the material, the Fermi level, and the shape of the emitting orbitals. The wavefunction in the vacuum between the electrodes is obtained with a close coupling method in a finite domain. Our model provides the emitted current density with respect to the applied field. This allows us to discriminate the different functional forms proposed to fit the Fowler–Nordheim emission curves. Our model also provides information on emission patterns. Electron total energy distributions are computed for different field intensities and compared with other theoretical and experimental results.
Published: 2023

4. Phase transformations and magnetostriction in Fe100−xGax bulk alloys

Author: Marco Coïsson, Kouassi Dakmak N’Dri, Lindor Diallo, Elena S. Olivetti, Luca Martino, Carlo P. Sasso, Federica Celegato, Gabriele Barrera, Massimo Pasquale, Paola Rizzi, Mery Malandrino, Olha Nakonechna, Fabien Cuvilly, Paola Tiberto, Jean Juraszek, Saïda Bahamida, Abdeslem Fnidiki, Istituto Nazionale di Ricerca Metrologica (INRiM), Groupe de physique des matériaux (GPM), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Università degli studi di Torino = University of Turin (UNITO), and Dipartimento di Chimica IFM and NIS
Subjects: [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], General Physics and Astronomy
Abstract: International audience; Fe–Ga alloys, containing 18, 21, and 23 at.% of Ga, were prepared in bulk form. In their as-cast state, they display a small magnetostriction, that is strongly improved after annealing at 1000 [Formula: see text]C for 24 h, and subsequent rapid cooling. Multiple characterization techniques, such as x-ray diffraction, differential scanning calorimetry, Mössbauer spectroscopy, temperature-dependent magnetization curves, hysteresis loops, magnetic force microscopy, and magnetostriction measurements, were exploited in synergy to gain a deep understanding of the structure–property relationships in the studied alloys, before and after annealing. The A2 phase, which is favored in the lower range of compositions and is promoted at the expense of the [Formula: see text] one by annealing, is responsible for characteristic dendritic and maze magnetic domains, and for the strong improvement of the magnetostriction, which almost reaches 240 ppm (transverse configuration) in the alloys with 18 at.% of Ga, after annealing.
Published: 2022

5. Preferential sublimation along threading dislocations in InGaN/GaN single quantum well for improved photoluminescence

Author: B. Damilano, S. Vézian, M. P. Chauvat, P. Ruterana, N. Amador-Mendez, S. Collin, M. Tchernycheva, P. Valvin, B. Gil, Centre de recherche sur l'hétéroepitaxie et ses applications (CRHEA), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA), Propriétés des Matériaux pour les Economies d'Energie (PM2E), Centre de recherche sur les Ions, les MAtériaux et la Photonique (CIMAP - UMR 6252), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Centre de Nanosciences et de Nanotechnologies (C2N), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire Charles Coulomb (L2C), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), ANR-18-CE24-0022,NAPOLI,Semiconducteurs III-N nanoporeux fabriqués par sublimation selective pour l'optoélectronique(2018), and ANR-11-EQPX-0020,GENESIS,Groupe d'Etudes et de Nanoanalyses des Effets d'IrradiationS(2011)
Subjects: [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], General Physics and Astronomy
Abstract: InGaN/GaN single quantum wells were grown by molecular beam epitaxy on the silicon substrate onto thin AlN and GaN buffer layers. The InGaN/GaN structure is porosified using a combination of SixNy nanomasking and sublimation and compared with a non-porous reference. The photoluminescence efficiency at room temperature of the porosified sample is improved by a factor reaching 40 compared with the reference sample. Plan-view and cross-sectional transmission electron microscopy images reveal that the remaining material is free of dislocation cores. The regions around dislocations are, thus, preferentially sublimated. This explains the strong photoluminescence improvement of nanoporous InGaN/GaN samples.
Published: 2022

6. Multiscale modeling of the dynamical conductivity of self-assembled nanoparticle networks: Numerical simulations vs analytical models

Author: L. Merle, A. Delpoux, A. Mlayah, J. Grisolia, Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Fédération de recherche « Matière et interactions » (FeRMI), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre d'élaboration de matériaux et d'études structurales (CEMES), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Équipe Photonique (LAAS-PHOTO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), and ANR-17-EURE-0009,NanoX,Science et Ingénierie à l'Echelle Nano(2017)
Subjects: [PHYS]Physics [physics], polypyrrole, General Physics and Astronomy, dielectric-relaxation, Charge-transport mechanism, gold
Abstract: International audience; Impedance spectroscopy experiments are able to reveal the fundamental charge transport properties of a wide variety of complex disordered and nano-structured materials provided that appropriate modeling tools are used. In this paper, we present a numerical simulation-based approach to model the dynamical conductivity of networks formed by self-assembled metal nanoparticles. Inter-particle nano-resistance and nano-capacitance are implemented at the nano-scale assuming inter-particle charge transfer and accumulation mechanisms that can be adapted depending on the nature of the nano-particles and the surrounding medium. The actual positions and spatial arrangements of the nanoparticles within the network are taken into consideration, allowing the attributes of percolating conducting routes to be extracted, classified, and compared in terms of path conductance and statistical distribution of path lengths. Our findings are contrasted to those obtained using analytic models, which are commonly used, but rely on strong assumptions about the electric properties of the conducting paths. We address these assumptions and show that in the case of weakly disordered systems, there is a general agreement between numerical simulations and analytic modeling-based approaches. In the case of disordered networks where the nano-particle size and position fluctuations are included, we show that the path length distribution is frequency-dependent and can differ significantly from the lognormal distribution usually assumed in the analytic models. The impedance of individual pathways may be extracted from the numerical simulations; we discovered that the conductance and susceptance of a specific path are frequency-dependent and inversely proportional to the path length only in ordered networks. Strong scattering of conductance values is caused by disorder effects. The developed numerical approach is generic and applies to most nano-devices where charge transport relies on percolation; it allows to bridge the gap between the nano-scale and micro-scale electric characteristics and, thus, permits a deeper understanding of the charge transport properties of nano-structured materials.
Published: 2022

7. Nanoscale imaging of dopant incorporation in n-type and p-type GaN nanowires by scanning spreading resistance microscopy

Author: Ece N. Aybeke, Alexandra-Madalina Siladie, Rémy Vermeersch, Eric Robin, Oleksandr Synhaivskyi, Bruno Gayral, Julien Pernot, Georges Brémond, Bruno Daudin, INL - Matériaux Fonctionnels et Nanostructures (INL - MFN), Institut des Nanotechnologies de Lyon (INL), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École Supérieure de Chimie Physique Électronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Nanophysique et Semiconducteurs (NPSC), PHotonique, ELectronique et Ingénierie QuantiqueS (PHELIQS), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Laboratoire d'Etude des Matériaux par Microscopie Avancée (LEMMA ), Modélisation et Exploration des Matériaux (MEM), Semi-conducteurs à large bande interdite (NEEL - SC2G), Institut Néel (NEEL), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), and Université Grenoble Alpes (UGA)
Subjects: [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], General Physics and Astronomy
Abstract: International audience
Published: 2022

8. Nano-analytical investigation of the forming process in an HfO2-based resistive switching memory

Author: Gauthier Lefevre, Tristan Dewolf, Nicolas Guillaume, Serge Blonkowski, Christelle Charpin-Nicolle, Eric Jalaguier, Etienne Nowak, Nicolas Bernier, Tom Blomberg, Marko Tuominen, Hessel Sprey, Guillaume Audoit, Sylvie Schamm-Chardon, Laboratoire des technologies de la microélectronique (LTM ), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Matériaux et dispositifs pour l'Electronique et le Magnétisme (CEMES-MEM), Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Resistive switching memories, Current-voltage characteristics, Atomic layer deposition, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], General Physics and Astronomy, Electron energy loss spectroscopy, Transmission electron microscopy
Abstract: International audience; Metal oxide-based resistive random access memory devices are highly attractive candidates for next-generation nonvolatile memories, butthe resistive switching phenomena remain poorly understood. This article focuses on the microscopic understanding of the initial formingstep, which is decisive for the switching process. The integrated resistive switching memory effect in Ti/HfO2/TiWN metal insulator metalstructures is studied. After forming, transmission electron microscopy investigations pointed out the presence of a funnel-shaped region, inthe ON state of the cell, where slightly oxidized Ti (TiOx) was present within HfO2 dielectric. Modeling of the measured ON state conductance of the cell with the semi-classical approximation is consistent with a conductive nanometric TiOx filament (or a sum of sub-nanometric TiOx filaments) present in the funnel-shaped region. The conductive area is likely formed by diffusion after the dielectric breakdown
Published: 2021

9. Burstlike first-order transformation studied by semi-adiabatic relaxation calorimetry

Author: X. Larose, Vincent Hardy, Michel Risser, Francois Guillou, R. Hamane, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), UBIBlue, Inner Mongolia Normal University [Hohhot], and ANR-17-CE05-0036,CoolMagEvo,Optimisation évolutionnaire de systèmes de réfrigération magnétique utilisant des alliages magnétocaloriques(2017)
Subjects: [PHYS]Physics [physics], Materials science, General Physics and Astronomy, Recalescence, Thermodynamics, 02 engineering and technology, Calorimetry, 021001 nanoscience & nanotechnology, 01 natural sciences, Heat capacity, Differential scanning calorimetry, Latent heat, 0103 physical sciences, Magnetic refrigeration, Relaxation (physics), 010306 general physics, 0210 nano-technology, Adiabatic process
Abstract: International audience; This paper reports on a mode of analysis of semi-adiabatic relaxation data allowing to account for exotic phenomena sometimes observed in first-order transitions. The principal interest is to get a detailed characterization of the latent heat while using the same experimental configuration as that employed for accurate heat capacity measurements outside the transition. Special attention is paid to the recalescence/antirecalescence effects as well as to the existence of spikes in the time-dependent exchange of latent heat. The present approach —based on the notion of “power of latent heat”— is shown to be consistent with differential scanning calorimetry, magnetization measurements and the usual analysis in terms of heat capacity. The study is carried out on a LaFe10.77Si1.23Co0.28 compound which belongs to one of the most promising families of giant magnetocaloric materials.
Published: 2021

10. Piezoelectric P(VDF-TrFE) film inkjet printed on silicon for high-frequency ultrasound applications

Author: Jean-Marc Gregoire, Franck Levassort, Samuel Callé, Aline Banquart, Frédéric Ossant, Sean Toffessi Siewe, Stéphanie Chevalliot, Arnaud Capri, Lionel Fritsch, Imagerie et cerveau (iBrain - Inserm U1253 - UNIV Tours ), Université de Tours-Institut National de la Santé et de la Recherche Médicale (INSERM), GREMAN (matériaux, microélectronique, acoustique et nanotechnologies) (GREMAN - UMR 7347), Université de Tours-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Université de Tours (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours (UT)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], 010302 applied physics, Coupling, Materials science, Silicon, business.industry, Poling, General Physics and Astronomy, chemistry.chemical_element, Context (language use), 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Piezoelectricity, Transducer, chemistry, 0103 physical sciences, Optoelectronics, Ultrasonic sensor, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, 0210 nano-technology, business, ComputingMilieux_MISCELLANEOUS, Deposition (law)
Abstract: We investigated the innovative processing of poly(vinylidene fluoride-trifluoroethylene) P(VDFx-TrFE1-x) (x = 83 mol. %) by inkjet printing to deliver uniform and thickness-controlled layers on silicon substrates. Here, we provide detailed processing steps and optimize film deposition conditions. The thickness coupling factor for a P(VDF-TrFE) film around 11 μm thick was 22%, demonstrating good electromechanical performance after poling. These multilayer structures were specifically for high-frequency, single-element ultrasonic transducer applications. The measurements of electro-acoustic responses were in water. The maximal frequency was centered at 33.2 MHz and had a fine axial resolution at 22 μm, corresponding to a fractional bandwidth at −6 dB of 100%. In the context of technological evolutions aimed at miniaturized devices and integrated electronics, these results allow for the consideration of complex structures such as multi-element transducers for high-frequency imaging applications.
Published: 2021

11. Scanning thermal microscopy on samples of varying effective thermal conductivities and identical flat surfaces

Author: Jonathan M. R. Weaver, Philipp Dobson, Eloïse Guen, Severine Gomes, Gordon B Mills, R. K. Rajkumar, Pierre-Olivier Chapuis, Chapuis, Pierre-Olivier, QUANTItative scanning probe microscopy techniques for HEAT transfer management in nanomaterials and nanodevices. - QUANTIHEAT - - EC:FP7:NMP2013-12-01 - 2017-11-30 - 604668 - VALID, Centre d'Energétique et de Thermique de Lyon (CETHIL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Kelvin Nanotechnology, University of Glasgow (University of Glasgow), European Project: 604668,EC:FP7:NMP,FP7-NMP-2013-LARGE-7,QUANTIHEAT(2013), and University of Glasgow
Subjects: 010302 applied physics, Materials science, Thermal resistance, General Physics and Astronomy, Thermal contact, 02 engineering and technology, Surface finish, Substrate (electronics), Scanning thermal microscopy, 021001 nanoscience & nanotechnology, Thermal conduction, 01 natural sciences, 0103 physical sciences, [SPI.MECA.THER]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Thermics [physics.class-ph], Wafer, Composite material, Thin film, 0210 nano-technology, [SPI.MECA.THER] Engineering Sciences [physics]/Mechanics [physics.med-ph]/Thermics [physics.class-ph]
Abstract: International audience; We propose an approach for the characterization of scanning thermal microscopy (SThM) probe response using a sample with silicon dioxide steps. The chessboard-like sample provides a series of nine surfaces made of the same material, with identical roughness, but consisting of different thicknesses of silica layers standing on a single silicon wafer. The nine regions have different effective thermal conductivities, allowing calibration of SThM probes within a given set of surface conditions. A key benefit is the possibility of comparing the spatial resolution and the sensitivity to vertical inhomogeneities of the sample for different probes. A model is provided to determine the thermal contact area and contact thermal resistance from the experimental data. The results underline that ballistic heat conduction can be significant in crystalline substrates below the top thin films, especially for film thicknesses lower than 200 nm and effective thermal contact radius lower than 200 nm. They also highlight the sensitivity of SThM to ultrathin films, as well as the substrate below micrometric films under in-air conditions but not when in vacuum. This work advances quantitative nanometer-scale thermal metrology, where usual photothermal methods are more difficult to implement.
Published: 2020

12. FORC signatures and switching-field distributions of dipolar coupled nanowire-based hysterons

Author: A. Pierrot, Thomas Blon, Fanny Béron, Nanomagnétisme (LPCNO), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC), Instituto de Fisica 'Gleb Wataghin' (INSTITUTO DE FISICA 'GLEB WATAGHIN'), Universidade Estadual de Campinas (UNICAMP), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Universidade Estadual de Campinas = University of Campinas (UNICAMP), and ANR-17-EURE-0009,NanoX,Science et Ingénierie à l'Echelle Nano(2017)
Subjects: 010302 applied physics, Physics, Condensed matter physics, Field (physics), Nanowire, General Physics and Astronomy, 02 engineering and technology, Coercivity, 021001 nanoscience & nanotechnology, 01 natural sciences, Nanomagnet, Dipole, Mean field theory, 0103 physical sciences, Log-normal distribution, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], 0210 nano-technology, Nanopillar
Abstract: Analysis of first-order reversal curves (FORCs) is a powerful tool to probe irreversible switching events in nanomagnet assemblies. As in essence switching events are related to the intrinsic properties of the constituents and their interactions, the resulting FORC diagrams contain much information that can be cross-linked and complex to deconvolute. In order to quantify the relevant parameters that drive the FORC diagrams of arrays of perpendicularly magnetized nanomagnets, we present step-by-step simulations of assemblies of hysterons to determine the specific signatures related to different known inputs. While we explored the consequences of dipolar interactions using either mean field or magnetostatic approaches, we completed by taking the hysteron switching field distribution (SFD) as either normal or lognormal. We demonstrated that the transition between FORC diagrams composed of an isolated interaction field distribution (IFD) and a wishbone shape operates via the SFD deviation, σ H s w, in the presence of a weakly dispersed interaction field. In the presence of a magnetostatic interaction field, the IFD profile is peaked and a coercive field distribution (CFD) sums to the IFD as σ H s w increases. A transition between IFD + CFD and wishbone shapes is clearly demonstrated as a function of the interaction field deviation σ H i n t. In addition, we demonstrate that whatever the considered cases, σ H s wcan be quantitatively extracted from the FORC diagrams within an error inferior to 10%. These findings are of interest for dipolar coupled perpendicularly magnetized nanomagnets, as in assemblies of magnetic nanowires and nanopillars, as well as bit patterned media.
Published: 2020

13. Evidence of weak antilocalization in quantum interference effects of (001) oriented La0.7Sr0.3MnO3–SrRuO3 superlattices

Author: Prahallad Padhan, Roshna Sobhanan Helen, Wilfrid Prellier, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), Indian Institute of Technology Madras (IIT Madras), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), and Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS]Physics [physics], 010302 applied physics, Fermi liquid theory, Materials science, Condensed matter physics, Magnetoresistance, Scattering, Magnon, Superlattice, General Physics and Astronomy, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Weak localization, Condensed Matter::Materials Science, Magnetic anisotropy, Ferromagnetism, 0103 physical sciences, [CHIM]Chemical Sciences, Condensed Matter::Strongly Correlated Electrons, 0210 nano-technology
Abstract: International audience; Quantum corrections to conductivity in the ferromagnetic La0.7Sr0.3MnO3 (LSMO) and SrRuO3 (SRO) thin films depend on the structural mismatches and interfaces accommodating ions and their spins. Here, by making interfaces of LSMO and SRO in the form of artificial superlattices, we achieve positive magnetoresistance (MR) and weak antilocalization (WAL), although the individual component shows negative MR and weak localization (WL). The [20 unit cell (u.c.) LSMO/3 u.c. SRO]×15 superlattice stabilizes in tetragonal symmetry associated with the rhombohedral and orthorhombic structures and demonstrates the occurrence of the single magnon scattering process. The low-field MR of the superlattice fit to the Hikami–Larkin–Nagaoka expression yields 595 Å phase coherence length (lϕ) with WAL of carriers. As the SRO layer thickness in the superlattice increases to 5 u.c., the value of lϕ = 292 Å decreases, and positive MR increases confirm the manifestation of WAL by SRO. The orthorhombic symmetry of the SRO is preserved in the [20 u.c. SRO/3 u.c. LSMO]×15 superlattice, which shows the existence of locally cooperative bond-length fluctuations and conduction due to the scattering of the electron by the Fermi liquid electrons, bond length, and spin fluctuations. However, as the LSMO layer thickness in the superlattice is increased to 5 u.c., the WL effect suppresses WAL at the low field. The spin–orbit coupling associated with magnetic anisotropy, i.e., spin and bond length fluctuations, modifies the WL in the superlattices and leads to WAL, thereby achieving positive MR.
Published: 2020

14. Mid-IR photothermal beam deflection technique for fast measurement of thermal diffusivity and highly sensitive subsurface imaging

Author: J. Younes, Maher Soueidan, Damien Fabrègue, Youssef Zaatar, Michel Kazan, Z. Harajli, Matériaux, ingénierie et science [Villeurbanne] (MATEIS), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Faculty of Sciences [Lebanese University], and Lebanese University [Beirut] (LU)
Subjects: [PHYS]Physics [physics], 010302 applied physics, Materials science, Phonon scattering, business.industry, Infrared, Phonon, General Physics and Astronomy, Infrared spectroscopy, 02 engineering and technology, Photothermal therapy, 021001 nanoscience & nanotechnology, Laser, Thermal diffusivity, 01 natural sciences, law.invention, law, 0103 physical sciences, Optoelectronics, Astrophysics::Earth and Planetary Astrophysics, 0210 nano-technology, business, Plasmon
Abstract: The resonances of phonon and plasmon modes make the absorbance coefficient of materials tremendously high in the mid-infrared spectral range, which allows for a mid-infrared excitation laser to heat the surface layers of these materials with high efficiency. Furthermore, phonon scattering by defects and defect-induced localized vibrational modes affect the local infrared dielectric function and, hence, the local infrared absorption coefficient. In this paper, we present a mid-infrared photothermal beam deflection technique that takes advantage of the strong interaction between infrared optical excitations and vibrational modes to measure the thermal diffusivity of materials without any sample preparation and takes advantage of the strong dependence of the infrared complex dielectric function on defects to detect subsurface defects with high sensitivity. We demonstrate the importance of the developed technique by measuring the thermal properties of highly transparent and reflective samples and detecting defects undetectable with any of the existing optical methods. Namely, using the developed technique, we find that the thermal diffusivities of high-quality Si, crystalline AlN, and crystalline α-SiO2 substrates are 1.00 ± 0.05, 0.67 ± 0.02, and 0.09 ± 0.01, respectively, and we record highly resolved images of structural subsurface defects as well as defects produced by ion-implantations at a depth of 62 μm under the surfaces of 4H-SiC substrates.
Published: 2020

15. Lack of linear magnetoelectric effect in ferrimagnetic distorted honeycomb Ni4Nb2O9

Author: Elodie Tailleur, Françoise Damay, François Fauth, Antoine Maignan, Christine Martin, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), and ALBA Synchrotron light source [Barcelone]
Subjects: 010302 applied physics, Materials science, Condensed matter physics, Neutron diffraction, Magnetoelectric effect, General Physics and Astronomy, 02 engineering and technology, Dielectric, Crystal structure, 021001 nanoscience & nanotechnology, 01 natural sciences, Magnetization, Ferrimagnetism, 0103 physical sciences, Orthorhombic crystal system, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 0210 nano-technology, Ground state, ComputingMilieux_MISCELLANEOUS
Abstract: M4A2O9 transition metal oxides, with M a divalent cation and A Nb or Ta, that exhibit a structure derived from corundum constitute an interesting class of materials due to their possible magnetoelectric properties. The lack of a linear magnetoelectric effect in Ni4Nb2O9, unlike Mn4Nb2O9 or Co4Nb2O9, is explained by a comprehensive investigation, combining synchrotron x-ray and neutron diffraction with magnetization, dielectric, and polarization measurements. The m′m′m magnetic point group associated with the Pb′cn′ ferrimagnetic structure induced below 76 K by the orthorhombic Pbcn structure of Ni4Nb2O9 forbids indeed such an effect. The crystal structure and magnetic ground state of Ni4Nb2O9 are discussed and compared with those of magnetoelectric P 3 ¯ c 1 M 4 A 2 O 9 compounds whose structure derives from corundum.M4A2O9 transition metal oxides, with M a divalent cation and A Nb or Ta, that exhibit a structure derived from corundum constitute an interesting class of materials due to their possible magnetoelectric properties. The lack of a linear magnetoelectric effect in Ni4Nb2O9, unlike Mn4Nb2O9 or Co4Nb2O9, is explained by a comprehensive investigation, combining synchrotron x-ray and neutron diffraction with magnetization, dielectric, and polarization measurements. The m′m′m magnetic point group associated with the Pb′cn′ ferrimagnetic structure induced below 76 K by the orthorhombic Pbcn structure of Ni4Nb2O9 forbids indeed such an effect. The crystal structure and magnetic ground state of Ni4Nb2O9 are discussed and compared with those of magnetoelectric P 3 ¯ c 1 M 4 A 2 O 9 compounds whose structure derives from corundum.
Published: 2020

16. Links between bismuth incorporation and surface reconstruction during GaAsBi growth probed by in situ measurements

Author: Alexandre Arnoult, Clara Cornille, Quentin Gravelier, Chantal Fontaine, Équipe Photonique (LAAS-PHOTO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Service Techniques et Équipements Appliqués à la Microélectronique (LAAS-TEAM), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), and Université de Toulouse (UT)
Subjects: III-V semiconductors, Materials science, Analytical chemistry, General Physics and Astronomy, chemistry.chemical_element, in situ measurements, 02 engineering and technology, Epitaxy, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, Bismuth, strain, Desorption, bismuth, 0103 physical sciences, 010302 applied physics, Surface stress, 021001 nanoscience & nanotechnology, chemistry, Electron diffraction, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Atomic ratio, 0210 nano-technology, Surface reconstruction, Molecular beam epitaxy
Abstract: Bismuth incorporation and surface reconstruction have been studied simultaneously during GaAsBi growth by molecular beam epitaxy by means of in situ wafer curvature monitoring and reflection high energy electron diffraction, respectively. Growth temperature and flux ratio have been varied successively. As/Ga atomic ratio close to unity has been applied for the study of the growth temperature effect. During the growth regime under the (1 × 3) reconstruction, Bi incorporation is found to be independent of the growth temperature, for temperatures where Bi desorption is insignificant. On the contrary, Bi incorporation becomes highly dependent on the growth temperature as soon as the (2 × 1) reconstruction regime is reached. Only for the lowest temperatures, the Bi incorporation reaches the same level during the (2 × 1) reconstruction than for the (1 × 3) reconstruction. When the As/Ga flux ratio is increased, the bismuth incorporation is observed to decrease for GaAsBi growth in the (2 × 1) reconstruction regime. Our results indicate that the (1 × 3) and (2 × 1) surface reconstructions are always successively observed and that an energy barrier has to overcome to transit from the (1 × 3) to the (2 × 1) reconstruction, with this mechanism being temperature dependent. Finally, a difference in surface stress with reconstruction has been identified.
Published: 2019

17. Influence of pressure assisted sintering and reaction sintering on microstructure and thermoelectric properties of bi-doped and undoped calcium cobaltite

Author: Bjoern Mieller, Ralf Moos, Sophie Bresch, Daniela Schoenauer-Kamin, Fabien Giovanelli, Torsten Rabe, Universität Bayreuth, GREMAN (matériaux, microélectronique, acoustique et nanotechnologies) (GREMAN - UMR 7347), Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours (UT)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, General Physics and Astronomy, Sintering, 02 engineering and technology, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, Abnormal grain growth, 7. Clean energy, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, law.invention, chemistry.chemical_compound, law, Seebeck coefficient, 0103 physical sciences, Thermoelectric effect, [CHIM.CRIS]Chemical Sciences/Cristallography, Calcination, Composite material, ComputingMilieux_MISCELLANEOUS, 010302 applied physics, Doping, 021001 nanoscience & nanotechnology, Microstructure, Cobaltite, [PHYS.COND.CM-S]Physics [physics]/Condensed Matter [cond-mat]/Superconductivity [cond-mat.supr-con], chemistry, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], [PHYS.COND.CM-SCE]Physics [physics]/Condensed Matter [cond-mat]/Strongly Correlated Electrons [cond-mat.str-el], 0210 nano-technology
Abstract: Calcium cobaltite (Ca3Co4O9) is considered as one of the most promising thermoelectric p-type oxides for energy harvesting applications at temperatures above 500 °C. It is challenging to sinter this material as its stability is limited to 920 °C. To facilitate a practicable and scalable production of Ca3Co4O9 for multilayer generators, a systematic study of the influence of powder calcination, Bi doping, reaction sintering, and pressure-assisted sintering (PAS) on microstructure and thermoelectric properties is presented. Batches of doped, undoped, calcined, and not calcined powders were prepared, tape-cast, and sintered with and without uniaxial pressure at 900 °C. The resulting phase compositions, microstructures, and thermoelectric properties were analyzed. It is shown that the beneficial effect of Bi doping observed on pressureless sintered samples cannot be transferred to PAS. Liquid phase formation induces distortions and abnormal grain growth. Although the Seebeck coefficient is increased to 139 μV/K by Bi doping, the power factor is low due to poor electrical conductivity. The best results were achieved by PAS of calcined powder. The dense and textured microstructure exhibits a high power factor of 326 μW/m K2 at 800 °C but adversely high thermal conductivity in the relevant direction. The figure of merit is higher than 0.08 at 700 °C.
Published: 2019

18. A multiscale procedure based on the stochastic kinetic mean field and the phase-field models for coarsening

Author: Helena Zapolsky, Gilles Demange, Bence Gajdics, Zoltán Erdélyi, János J. Tomán, Groupe de physique des matériaux (GPM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), University of Debrecen Egyetem [Debrecen], Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), and Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS]Physics [physics], 010302 applied physics, Materials science, Field (physics), Nucleation, General Physics and Astronomy, Phase field models, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Matrix (mathematics), Mean field theory, Consistency (statistics), 0103 physical sciences, Initial value problem, Statistical physics, 0210 nano-technology, CALPHAD, ComputingMilieux_MISCELLANEOUS
Abstract: We report a quantitative multiscale (MS) procedure based on the recently developed Stochastic Kinetic Mean Field approach (SKMF) [Erdelyi, M. Pasichnyy, V. Bezpalchuk, J. J. Toman, B. Gajdics, and A. M. Gusak, Comput. Phys. Commun. 204, 31–37 (2016)], combined with the Phase Field model (PFM) and CALPHAD database, to study the nucleation-growth-coarsening process in alloys. The SKMF approach reproduces the nucleation and early growth of precipitates in the matrix, and the PFM then simulates the coarsening of the microstructure. To ensure the consistency of the procedure, the length and time scales of SKMF and PFM are explicitly connected. Moreover, both the effective interaction energies used in the SKMF and the free energy used in the PFM are taken from CALPHAD database. Two different implementations of the procedure are proposed. First, the postnucleation microstructure as provided by SKMF is used as the initial condition for subsequent PFM simulations. Second, only the particle size distribution and particle density are transferred to PFM, thereby giving access to bigger systems. The proposed procedure is tested in the specific case of the Ag-Cu model alloy.We report a quantitative multiscale (MS) procedure based on the recently developed Stochastic Kinetic Mean Field approach (SKMF) [Erdelyi, M. Pasichnyy, V. Bezpalchuk, J. J. Toman, B. Gajdics, and A. M. Gusak, Comput. Phys. Commun. 204, 31–37 (2016)], combined with the Phase Field model (PFM) and CALPHAD database, to study the nucleation-growth-coarsening process in alloys. The SKMF approach reproduces the nucleation and early growth of precipitates in the matrix, and the PFM then simulates the coarsening of the microstructure. To ensure the consistency of the procedure, the length and time scales of SKMF and PFM are explicitly connected. Moreover, both the effective interaction energies used in the SKMF and the free energy used in the PFM are taken from CALPHAD database. Two different implementations of the procedure are proposed. First, the postnucleation microstructure as provided by SKMF is used as the initial condition for subsequent PFM simulations. Second, only the particle size distribution and pa...
Published: 2019

19. Influence of mesoporous or parasitic BiFeO 3 structural state on the magnetization reversal in multiferroic BiFeO 3/Ni 81Fe 19 polycrystalline bilayers

Author: Y. Le Grand, W. Jahjah, Cécile Marcelot, D. T. Dekadjevi, J.-Ph. Jay, A. R. E. Prinsloo, A. Fessant, J. Richy, C. J. Sheppard, Bénédicte Warot-Fonrose, David Spenato, Laboratoire de magnétisme de Bretagne (LMB), Université de Brest (UBO)-Institut Brestois du Numérique et des Mathématiques (IBNM), Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), Centre d'élaboration de matériaux et d'études structurales (CEMES), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Interférométrie, In situ et Instrumentation pour la Microscopie Electronique (CEMES-I3EM), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Queen Alexandra Hospital, Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), and Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse)
Subjects: Materials science, Condensed matter physics, General Physics and Astronomy, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Ferroelectricity, chemistry.chemical_compound, Exchange bias, chemistry, Ferromagnetism, Phase (matter), 0103 physical sciences, Antiferromagnetism, Multiferroics, Crystallite, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 010306 general physics, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS, Bismuth ferrite
Abstract: Coupled ferromagnetic and antiferromagnetic bilayers are an important class of materials that allow manipulating magnetic properties, including the interfacial exchange bias phenomenon. Bismuth ferrite, BiFeO 3, is the most studied single-phase magnetoelectric multiferroic due to its unique ferroelectric and antiferromagnetic orderings well above room temperature. We report on a systematic experimental study regarding the direct correlation between the Bi 2O 3 parasitic phase concentration in the BiFeO 3 and the magnetic properties of the polycrystalline heterostructure BiFeO 3/Ni 81Fe 19 deposited via magnetron sputtering. It was found that the macroscopic exchange field, that arises from exchange bias coupling, is zero for phase-pure BiFeO 3 and increases up to 18 Oe on increasing the concentration of Bi 2O 3. This trend is in agreement with the azimuthal behavior of the magnetization reversal. The structural characterization also indicates that phase-pure BiFeO 3 has a disordered mesoporous structure. The influence of the Bi 2O 3 parasitic phase and mesoporous state, that is known to exist and introduce defects in the polycrystalline bilayers of BiFeO 3/Ni 81Fe 19, on the magnetization reversal and exchange bias coupling is reported for the first time in this study.Coupled ferromagnetic and antiferromagnetic bilayers are an important class of materials that allow manipulating magnetic properties, including the interfacial exchange bias phenomenon. Bismuth ferrite, BiFeO 3, is the most studied single-phase magnetoelectric multiferroic due to its unique ferroelectric and antiferromagnetic orderings well above room temperature. We report on a systematic experimental study regarding the direct correlation between the Bi 2O 3 parasitic phase concentration in the BiFeO 3 and the magnetic properties of the polycrystalline heterostructure BiFeO 3/Ni 81Fe 19 deposited via magnetron sputtering. It was found that the macroscopic exchange field, that arises from exchange bias coupling, is zero for phase-pure BiFeO 3 and increases up to 18 Oe on increasing the concentration of Bi 2O 3. This trend is in agreement with the azimuthal behavior of the magnetization reversal. The structural characterization also indicates that phase-pure BiFeO 3 has a ...
Published: 2018

20. Field-effect passivation of Si by ALD-Al2O3: Second harmonic generation monitoring and simulation

Author: D. Blanc-Pelissier, M. Gri, G. Vitrant, A. Bouchard, Gerard Ghibaudo, I. Ionica, Sorin Cristoloveanu, D Damianos, X. Mescot, Ming Lei, A. Kaminski-Cachopo, J. Changala, Institut de Microélectronique, Electromagnétisme et Photonique - Laboratoire d'Hyperfréquences et Caractérisation (IMEP-LAHC ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), INL - Photovoltaïque (INL - PV), Institut des Nanotechnologies de Lyon (INL), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Femtometrix, Région Rhône-Alpes, Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-École Centrale de Lyon (ECL), Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)
Subjects: Materials science, Passivation, non-destructive characterization, Oxide, General Physics and Astronomy, Field effect, 02 engineering and technology, 01 natural sciences, high-k, [SPI.MAT]Engineering Sciences [physics]/Materials, chemistry.chemical_compound, Electric field, Al2O3, 0103 physical sciences, surface passivation, High-κ dielectric, 010302 applied physics, business.industry, Second-harmonic generation, Carrier lifetime, interface electric field 2, 021001 nanoscience & nanotechnology, Second Harmonic Generation, chemistry, Optoelectronics, 0210 nano-technology, business, Microwave
Abstract: International audience; This paper investigates the ability of second harmonic generation (SHG) to probe the passivation quality of atomic layer deposited (ALD) Al2O3 on Si by estimating the induced interface electric field due to fixed charges in the oxide. Samples with various oxide charges (Qox) and interface state densities (Dit) were fabricated, using different deposition parameters. The samples were characterized by capacitance-voltage (C-V) and microwave photoconductance decay (µ-PCD) measurements in order to evaluate Qox and Dit, as well as the effective minority carrier lifetime τeff. The SHG results were consistent with Qox, Dit and τeff values, proving the ability of the technique to monitor the interfacial quality in a contactless and non-destructive way. Optical simulations which use the electric field values obtained from the C-V measurements could reproduce the measured SHG signal. This demonstrates that SHG coupled with optical simulation can give access to the electric field magnitude and thus characterize the electrical properties of oxide/Si interfaces.
Published: 2018

21. Toward interactive scanning tunneling microscopy simulations of large-scale molecular systems in real time

Author: Xavier Bouju, Marc-André Dubois, Alain Rochefort, Regroupement Québécois sur les Matériaux de Pointe (RQMP), École Polytechnique de Montréal (EPM)-Université de Sherbrooke (UdeS)-McGill University = Université McGill [Montréal, Canada]-Université de Montréal (UdeM)-Fonds Québécois de Recherche sur la Nature et les Technologies (FQRNT), Groupe NanoSciences (CEMES-GNS), Centre d'élaboration de matériaux et d'études structurales (CEMES), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), École Polytechnique de Montréal (EPM)-Université de Sherbrooke [Sherbrooke]-Université de Montréal [Montréal]-McGill University-Fonds Québécois de Recherche sur la Nature et les Technologies (FQRNT), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, molecular systems, Supramolecular chemistry, General Physics and Astronomy, 02 engineering and technology, Electronic structure, 010402 general chemistry, 01 natural sciences, law.invention, symbols.namesake, law, Molecule, 8265+r Keywords: STM, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], ComputingMilieux_MISCELLANEOUS, numbers: 7320-r, parallel computing, large-scale simulation, 7115Nc, Molecular orbital theory, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Molecular geometry, Chemical physics, [PHYS.COND.CM-GEN]Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other], surface adsorption, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], symbols, Density functional theory, van der Waals force, Scanning tunneling microscope, 0210 nano-technology
Abstract: We have developed a simulation tool in which structural or chemical modifications of an adsorbed molecular layer can be interactively performed, and where structural relaxation and nearly real-time evaluation of a scanning tunneling microscopy (STM) image are considered. This approach is built from an optimized integration of the atomic superposition and electron delocalization molecular orbital theory (ASED-MO) to which a van der Waals correction term is added in conjunction with a non-linear optimization algorithm based on the Broyden-Fletcher-Goldfarb-Shanno method. This integrated approach provides reliable optimized geometries for adsorbed species on metallic surfaces in a reasonable time. Although we performed a major revision of the ASED-MO parameters, the proposed computational approach can accurately reproduce the geometries of a various amount of covalent molecules and weakly bonded complexes contained in two well-defined datasets. More importantly, the relaxation of adsorbed species on a metal surface leads to molecular geometries in good agreement with experimental and Density Functional Theory results. From this, the electronic structure obtained from ASED-MO is used to compute the STM image of the system nearly in real-time using the Tersoff-Hamann formalism. We developed a parallelization strategy that uses Graphics Processing Units to reduce the computing time of STM simulation by a factor of 30. Such improvements allow one to simulate STM images of large supramolecular arrangements and to investigate the influence of realistic local chemical or structural defects on metal surfaces.We have developed a simulation tool in which structural or chemical modifications of an adsorbed molecular layer can be interactively performed, and where structural relaxation and nearly real-time evaluation of a scanning tunneling microscopy (STM) image are considered. This approach is built from an optimized integration of the atomic superposition and electron delocalization molecular orbital theory (ASED-MO) to which a van der Waals correction term is added in conjunction with a non-linear optimization algorithm based on the Broyden-Fletcher-Goldfarb-Shanno method. This integrated approach provides reliable optimized geometries for adsorbed species on metallic surfaces in a reasonable time. Although we performed a major revision of the ASED-MO parameters, the proposed computational approach can accurately reproduce the geometries of a various amount of covalent molecules and weakly bonded complexes contained in two well-defined datasets. More importantly, the relaxation of adsorbed species on a metal ...
Published: 2018

22. Phase field model of the nanoscale evolution during the explosive crystallization phenomenon

Author: Enrico Napolitani, S. Boninelli, Salvatore Francesco Lombardo, M. G. Grimaldi, Karim Huet, Ioannis Deretzis, Fuccio Cristiano, A. La Magna, Università degli studi di Catania [Catania], MATIS CNR-INFM Dipartimento di Metodologie Fisiche e Chimiche (DMFCI) (MATIS), Università degli studi di Catania [Catania]- Istituto Nazionale di Fisica Nucleare (INFN), Équipe Matériaux et Procédés pour la Nanoélectronique (LAAS-MPN), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, ScreenCell [Sarcelles], University of Padova [Padova, Italy], Università degli studi di Catania = University of Catania (Unict), Università degli studi di Catania = University of Catania (Unict)- Istituto Nazionale di Fisica Nucleare (INFN), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), and Università degli Studi di Padova = University of Padua (Unipd)
Subjects: 010302 applied physics, Exothermic reaction, Materials science, Explosive material, Annealing (metallurgy), Kinetics, General Physics and Astronomy, Nanosecond, explosive crystallization, 01 natural sciences, Instability, [SPI.MAT]Engineering Sciences [physics]/Materials, law.invention, [SPI]Engineering Sciences [physics], 13. Climate action, law, Chemical physics, 0103 physical sciences, Phase field model, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, Crystallization, 010306 general physics, Nanoscopic scale
Abstract: Explosive crystallization is a well known phenomenon occurring due to the thermodynamic instability of strongly under-cooled liquids, which is particularly relevant in pulsed laser annealing processes of amorphous semiconductor materials due to the globally exothermic amorphous-toliquid-to-crystal transition pathway. In spite of the assessed understanding of this phenomenon, quantitative predictions of the material kinetics promoted by explosive crystallization are hardly achieved due to the lack of a consistent model able to simulate the concurrent kinetics of the amorphous-liquid and liquid-crystal interfaces. Here, we propose a multi-well phase-field model specifically suited for the simulation of explosive crystallization induced by pulsed laser irradiation in the nanosecond time scale. The numerical implementation of the model is robust despite the discontinuous jumps of the interface speed induced by the phenomenon. The predictive potential of the simulations is demonstrated by means of comparisons of the modelling predictions with experimental data in terms of in situ reflectivity measurements and ex-situ micro-structural and chemical characterization. Published by AIP Publishing.
Published: 2018

23. Effect of a lattice-matched GaAsSb capping layer on the structural properties of InAs/InGaAs/InP quantum dots

Author: Antoine Létoublon, PM Paul Koenraad, Maximilien Bonnet-Eymard, Nicolas Bertru, JM José Maria Ulloa, Cobra (COBRA), Eindhoven University of Technology [Eindhoven] (TU/e), Fonctions Optiques pour les Technologies de l'informatiON (FOTON), Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-École Nationale Supérieure des Sciences Appliquées et de Technologie (ENSSAT)-Télécom Bretagne, reseau d'excellence Sandie, oui, Photonics and Semiconductor Nanophysics, Semiconductor Nanostructures and Impurities, Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-École Nationale Supérieure des Sciences Appliquées et de Technologie (ENSSAT)-Télécom Bretagne-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010302 applied physics, Materials science, business.industry, General Physics and Astronomy, antimony quantum dots X-STM, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Atomic units, Gallium arsenide, law.invention, chemistry.chemical_compound, Semiconductor quantum dots, chemistry, Quantum dot, law, Lattice (order), 0103 physical sciences, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Optoelectronics, Self-assembly, Scanning tunneling microscope, 0210 nano-technology, business
Abstract: The influence of a lattice-matched GaAsSb capping layer on the structural properties of self-assembled InAs quantum dots (QDs) grown on InP substrates is studied on the atomic scale by cross-sectional scanning tunneling microscopy. While lattice-matched In0.53 Ga0.47 As -capped QDs are clearly truncated pyramids, GaAs0.51 Sb0.49 -capped QDs grown under the same conditions look like full pyramids and exhibit a larger height, indicating that capping with GaAsSb reduces dot decomposition. Since there are no differences in strain between the two capping layers, this behavior is most likely related to the surfactant effect of Sb, which stabilizes the growth front and avoids adatom migration. © 2010 American Institute of Physics. U7 - Export Date: 2 August 2010 U7 - Source: Scopus U7 - Art. No.: 074309
Published: 2010

24. In-depth porosity control of mesoporous silicon layers by an anodization current adjustment

Author: Julie Lascaud, Dominique Certon, Damien Valente, Thomas Defforge, Gaël Gautier, GREMAN (matériaux, microélectronique, acoustique et nanotechnologies) (GREMAN - UMR 7347), Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours (UT)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Silicon, Anodizing, General Physics and Astronomy, chemistry.chemical_element, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, Porous silicon, 01 natural sciences, Isotropic etching, 0104 chemical sciences, chemistry, Etching (microfabrication), [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, Composite material, 0210 nano-technology, Porosity, Layer (electronics), Current density, ComputingMilieux_MISCELLANEOUS
Abstract: The formation of thick mesoporous silicon layers in P+-type substrates leads to an increase in the porosity from the surface to the interface with silicon. The adjustment of the current density during the electrochemical etching of porous silicon is an intuitive way to control the layer in-depth porosity. The duration and the current density during the anodization were varied to empirically model porosity variations with layer thickness and build a database. Current density profiles were extracted from the model in order to etch layer with in-depth control porosity. As a proof of principle, an 80 μm-thick porous silicon multilayer was synthetized with decreasing porosities from 55% to 35%. The results show that the assessment of the in-depth porosity could be significantly enhanced by taking into account the pure chemical etching of the layer in the hydrofluoric acid-based electrolyte.
Published: 2017

25. Investigation of laser-ablated ZnO thin films grown with Zn metal target: A structural study

Author: Thirumalai Venkatesan, V. N. Kulkarni, Laurence Méchin, Arnaud Fouchet, B. Mercey, Wilfrid Prellier, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Microbiologie Industrielle, Ecole Nationale Supérieure des Industries Agricoles et alimentaires, and National University of Singapore (NUS)
Subjects: [PHYS]Physics [physics], Diffraction, Condensed Matter - Materials Science, Materials science, Analytical chemistry, Materials Science (cond-mat.mtrl-sci), FOS: Physical sciences, General Physics and Astronomy, [CHIM.MATE]Chemical Sciences/Material chemistry, Epitaxy, Laser, law.invention, Pulsed laser deposition, law, Oxidizing agent, [CHIM]Chemical Sciences, Deposition (phase transition), Thin film, Spectroscopy
Abstract: High quality ZnO thin films were gown using the pulsed laser deposition technique on (0001) Al$_2$O$_3$ substrates in an oxidizing atmosphere, using a Zn metallic target. We varied the growth conditions such as the deposition temperature and the oxygen pressure. First, using a battery of techniques such as x-rays diffraction, Rutherford Backscattering spectroscopy and atomic force microscopy, we evaluated the structural quality, the stress and the degree of epitaxy of the films. Second, the relations between the deposition conditions and the structural properties, that are directly related to the nature of the thin films, are discussed qualitatively. Finally, a number of issues on how to get good-quality ZnO films are addressed., Comment: To be published in Jour. Appl. Phys. (15 August 2004)
Published: 2004

26. Chemisorption on nickel nanoparticles of various shapes: Influence on magnetism

Author: Marie-José Casanove, Bruno Chaudret, Nadège Cordente, C. Amiens, François Senocq, Marc Respaud, Laboratoire de chimie de coordination (LCC), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Nanophysique Magnétisme et Optoélectronique (LNMO), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT), Centre d'élaboration de matériaux et d'études structurales (CEMES), Surfaces, Interfaces et Nano-Objets (CEMES-SINanO), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3)
Subjects: Materials science, General Physics and Astronomy, Infrared spectroscopy, Nanoparticle, chemistry.chemical_element, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Crystallography, Magnetization, Nickel, Magnetic anisotropy, chemistry, Chemisorption, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Magnetic nanoparticles, Physical chemistry, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS, Superparamagnetism
Abstract: Nanoparticles of nickel have been obtained in solution through reaction of an organometallic precursor, Ni(COD)2 (COD=cycloocta-1,5-diene), with dihydrogen, in the presence of various stabilizing agents. X-ray diffraction studies evidence a face-centered-cubic structure for all samples. Spherical isolated superparamagnetic nanoparticles (d∼4.5 nm) are produced in the presence of poly(N-vinylpyrrolid-2-one). They display a magnetization value comparable to that of bulk nickel, as determined from superconducting quantum iinterference device (SQUID) measurements. Exposure of the surface of the nanoparticles to CO, leading to CO coordination as monitored by infrared spectroscopy, or to methanol, strongly reduces their magnetization. This reduction corresponds respectively to one or two magnetically inactive layers of nickel atoms at the nanoparticles surface. The production of elongated nanoparticles was favored when either trioctylphosphineoxide or hexadecylamine (HDA) were used as stabilizing agents. In thi...
Published: 2003

27. In situ monitoring of the growth and characterization of (PrMnO3)n(SrMnO3)n superlattices

Author: M. Hervieu, Paul A. Salvador, B. Raveau, Wilfrid Prellier, Anne-Marie Haghiri-Gosnet, D. Chippaux, B. Mercey, Ch. Simon, Ph. Lecoeur, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Centro de Investigaciones Energéticas Medioambientales y Tecnológicas [Madrid] (CIEMAT), Laboratoire de Microstructures et de Microélectronique (L2M), and Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS]Physics [physics], Materials science, Superlattice, Analytical chemistry, General Physics and Astronomy, Heterojunction, [CHIM.MATE]Chemical Sciences/Material chemistry, Pulsed laser deposition, law.invention, Magnetization, Electron diffraction, law, visual_art, X-ray crystallography, visual_art.visual_art_medium, [CHIM]Chemical Sciences, Ceramic, Electron microscope
Abstract: Superlattices having the general formula (PrMnO3)n(SrMnO3)n were grown from PrMnO3 and SrMnO3 ceramic targets by pulsed laser deposition (PLD) in low pressures (laser-MBE) and were compared to those grown in standard pressures (“classical”-PLD). For the laser-MBE grown films, the growth was monitored and the thickness of each deposited layer was controlled in situ at the level of one unit cell using reflection high energy electron diffraction. Perfectly ordered stacks of PrMnO3 and SrMnO3 layers were thusly grown. The transport and magnetic properties of the laser-MBE superlattices differ from similar superlattices grown in a “classical” PLD system. The different physical behaviors are explained by the combination of two factors, the roughness of the interfaces between the different layers and the oxygen deficiency, both of which are larger in the films grown using classical-PLD. X-ray and electron diffraction, as well as high-resolution electron microscopy, were used to characterize the structures of the...
Published: 2003

28. Crystallinity, surface morphology, and magnetic properties of La0.7Sr0.3MnO3 thin films: An approach based on the laser ablation plume range models

Author: Wilfrid Prellier, Anne-Marie Haghiri-Gosnet, M. Koubaa, Rachel Desfeux, Ph. Lecoeur, B. Mercey, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique des Matériaux.Sfax 3000, Tunisia., Université de Sfax - University of Sfax, Laboratoire de Microstructures et de Microélectronique (L2M), Centre National de la Recherche Scientifique (CNRS), UCCS Équipe Couches Minces & Nanomatériaux, Unité de Catalyse et Chimie du Solide - UMR 8181 (UCCS), and Université d'Artois (UA)-Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université d'Artois (UA)-Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS]Physics [physics], Shock wave, Materials science, Laser ablation, Condensed matter physics, Analytical chemistry, General Physics and Astronomy, [CHIM.MATE]Chemical Sciences/Material chemistry, Substrate (electronics), Epitaxy, Microstructure, Pulsed laser deposition, Crystallinity, [CHIM]Chemical Sciences, Thin film, ComputingMilieux_MISCELLANEOUS
Abstract: We report on a systematic investigation of the influence of pulsed laser deposition (PLD) parameters upon the microstructure, surface morphology, and magnetic properties of La0.7Sr0.3MnO3 (LSMO) thin films grown on (100) SrTiO3 substrates. The optimization of the physical properties requires a careful exploration of the main parameters such as the oxygen pressure P and the target-to-substrate distance D. We show that there is a strong correlation between both these parameters and an optimal distance (D=L0), which can be calculated from a PD3 scaling law (in accordance with a shock wave model). This particular value L0 corresponds to the distance for which all species are thermalized in the plume. In the D–P diagram, L0 defines two distinct regions for the morphology and the microstructure: (i) when D 1 μm) morphology. These films are perfectly epitaxial on the substrate, single-phase and not relaxed. (ii) When D≫L0, the films are colum...
Published: 2003

29. Surface effects on shape, self-organization and photoluminescence of InAs islands grown on InAlAs/InP(001)

Author: G. Hollinger, Julien Brault, Taha Benyattou, José Olivares, Bassem Salem, Geneviève Grenet, Georges Bremond, Michel Gendry, Laboratoire d'électronique, optoélectronique et microsystèmes (LEOM), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique de la matière (LPM), Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Statistical mechanics models, Materials science, Nanostructure, Photoluminescence, Solid-state physics, General Physics and Astronomy, 02 engineering and technology, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, Atomic force microscopy, 0103 physical sciences, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, Surface physics, Quantum well, 010302 applied physics, Condensed matter physics, Quantum dots, business.industry, Quantum wires, 021001 nanoscience & nanotechnology, Polarization (waves), Semiconductors, Quantum dot, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Optoelectronics, 0210 nano-technology, business, Surface reconstruction, Epitaxy, Molecular beam epitaxy
Abstract: International audience; InAs nanostructures were grown on In 0.52 Al 0.48 As alloy lattice matched on InP001 substrates by molecular beam epitaxy using specific growth parameters in order to improve island self-organization. We show how the change in InAs surface reconstruction via growth temperature from (24) to (21) and/or the use of InAlAs initial buffer surface treatments improve the island shape homogeneity either as quantum wires or as quantum dots. Differences in island shape and in carrier confinement are shown by atomic force microscopy and by photoluminescence measurements, respectively. We point out that such shape amendments induce drastic improvements to island size distribution and discernible changes in photoluminescence properties, in particular concerning polarization.
Published: 2002

30. Influence of average size and interface passivation on the spectral emission of Si nanocrystals embedded in SiO2

Author: Alejandro Pérez-Rodríguez, B. Garrido Fernandez, M. Carrada, María M. López, Caroline Bonafos, Alain Claverie, Joan Ramon Morante, C. García, Universitat de Barcelona, Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)
Subjects: Materials science, Photoluminescence, Passivation, Annealing (metallurgy), Band gap, Population, Analytical chemistry, Nucleation, General Physics and Astronomy, 02 engineering and technology, 01 natural sciences, 0103 physical sciences, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], education, ComputingMilieux_MISCELLANEOUS, 010302 applied physics, education.field_of_study, Optical properties, business.industry, Ciència dels materials, 021001 nanoscience & nanotechnology, Dark field microscopy, Nanocrystal, Optoelectronics, Propietats òptiques, 0210 nano-technology, business
Abstract: The correlation between the structural (average size and density) and optoelectronic properties [band gap and photoluminescence (PL)] of Si nanocrystals embedded in SiO2 is among the essential factors in understanding their emission mechanism. This correlation has been difficult to establish in the past due to the lack of reliable methods for measuring the size distribution of nanocrystals from electron microscopy, mainly because of the insufficient contrast between Si and SiO2. With this aim, we have recently developed a successful method for imaging Si nanocrystals in SiO2 matrices. This is done by using high-resolution electron microscopy in conjunction with conventional electron microscopy in dark field conditions. Then, by varying the time of annealing in a large time scale we have been able to track the nucleation, pure growth, and ripening stages of the nanocrystal population. The nucleation and pure growth stages are almost completed after a few minutes of annealing time at 1100°C in N2 and afterward the ensemble undergoes an asymptotic ripening process. In contrast, the PL intensity steadily increases and reaches saturation after 3-4 h of annealing at 1100°C. Forming gas postannealing considerably enhances the PL intensity but only for samples annealed previously in less time than that needed for PL saturation. The effects of forming gas are reversible and do not modify the spectral shape of the PL emission. The PL intensity shows at all times an inverse correlation with the amount of Pb paramagnetic centers at the Si-SiO2 nanocrystal-matrix interfaces, which have been measured by electron spin resonance. Consequently, the Pb centers or other centers associated with them are interfacial nonradiative channels for recombination and the emission yield largely depends on the interface passivation. We have correlated as well the average size of the nanocrystals with their optical band gap and PL emission energy. The band gap and emission energy shift to the blue as the nanocrystal size shrinks, in agreement with models based on quantum confinement. As a main result, we have found that the Stokes shift is independent of the average size of nanocrystals and has a constant value of 0.26±0.03 eV, which is almost twice the energy of the Si¿O vibration. This finding suggests that among the possible channels for radiative recombination, the dominant one for Si nanocrystals embedded in SiO2 is a fundamental transition spatially located at the Si¿SiO2 interface with the assistance of a local Si-O vibration.
Published: 2002

31. Cryogenic plasma-processed silicon microspikes as a high-performance anode material for lithium ion-batteries

Author: François Tran-Van, Thomas Tillocher, Jérôme Wolfman, Erwann Luais, Remi Dussart, Joe Sakai, Fouad Ghamouss, GREMAN (matériaux, microélectronique, acoustique et nanotechnologies) (GREMAN - UMR 7347), Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours (UT)-Centre National de la Recherche Scientifique (CNRS), Physico-chimie des Matériaux et des Electrolytes pour l'Energie (PCM2E), Université de Tours (UT), Groupe de recherches sur l'énergétique des milieux ionisés (GREMI), Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours-Centre National de la Recherche Scientifique (CNRS), and Université de Tours
Subjects: Materials science, Silicon, General Physics and Astronomy, chemistry.chemical_element, 02 engineering and technology, black-silicon, Cryoetching, 010402 general chemistry, 01 natural sciences, 7. Clean energy, Lithium-ion battery, [SPI]Engineering Sciences [physics], chemistry.chemical_compound, Li-ion battery, Wafer, Composite material, Reactive-ion etching, Microstructure, Black silicon, 021001 nanoscience & nanotechnology, Anode, 0104 chemical sciences, chemistry, Lithium, 0210 nano-technology, Faraday efficiency
Abstract: International audience; Micro- or nano-structuring is essential in order to use Si as an anode material for lithium ion batteries. In the present study, we attempted to use Si wafers with a spiky microstructure (SMS), the so-called black-Si, prepared by a cryogenic reactive ion etching process with an SF6/O2 gas mixture, for Li half-cells. The SMS with various sizes of spikes from 2.0 μm (height) × 0.2 μm (width) to 21 μm × 1.0 μm was etched by varying the SF6/O2 gas flow ratio. An anode of SMS of 11 μm-height in average showed stable charge/discharge capacity and Coulombic efficiency higher than 99% for more than 300 cycles, causing no destruction to any part of the Si wafer. The spiky structure turned columnar after cycles, suggesting graded lithiation levels along the length. The present results suggest a strategy to utilize a wafer-based Si material for an anode of a lithium ion battery durable against repetitive lithiation/delithiation cycles.
Published: 2017

32. Flexoelectric response in soft polyurethane films and their use for large curvature sensing

Author: M. Tabellout, Raynald Seveno, A. Kassiba, Victor Ishrayelu Merupo, Benoit Guiffard, Institut d'Électronique et des Technologies du numéRique (IETR), Université de Nantes (UN)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Institut des Molécules et Matériaux du Mans (IMMM), Le Mans Université (UM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), French Region Pays de la Loire, RFI program WISE, Université de Nantes (UN)-Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Nantes Université (NU)-Université de Rennes 1 (UR1), Institut d'Electronique et de Télécommunications de Rennes (IETR), and Le Mans Université (UM)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Permittivity, Cantilever, Materials science, Flexoelectricity, Piezoelectricity, General Physics and Astronomy, 02 engineering and technology, Dielectric, Curvature, Elastomer, 01 natural sciences, Radius of curvature (optics), [SPI]Engineering Sciences [physics], 0103 physical sciences, Structural acoustics, Composite material, Materials, 010302 applied physics, General physics, Acoustics, Condensed matter physics, 021001 nanoscience & nanotechnology, Condensed matter properties, Electrical properties, Dielectrics, 0210 nano-technology
Abstract: International audience; The flexoelectric effect is simply defined as the coupling between the strain gradient and polarization in solid dielectrics. It may be seen as an alternative transduction mechanism to the piezoelectric effect to directly sense the curvature of bent flexible thin structures. In the case of large curvatures, flexible and compliant sensors are required and soft polar elastomers may be suitable for curvature sensing. In this study, we report the flexoelectric characterization of soft semi-crystalline polyurethane (PU) films with thicknesses ranging from 1.7 μm to 350 μm. Dynamic bending experiments have been performed on PU films deposited onto rigid steel substrates in the vicinity of the mechanical resonance frequency of the cantilever beams. Quasi-static flexoelectric coefficients of PU films could be obtained by using a classical oscillating model. A global large increase of μ′12 with the decreasing film thickness was found, especially for thicknesses lower than 25 μm. The variation of μ′12 is explained by the presence of a Young's Modulus gradient through the thickness of PU films. Besides, a concomitant uncommon dramatic decrease in the dielectric constant is observed. The combination of these two effects contributes to enhancing the flexocoupling “F” constant with the decreasing thickness. At last, the potential use of a 6.6 μm-thick soft PU film as a large curvature sensor has been experimentally demonstrated by subjecting a flexible Aluminum foil/Polyethylene terephthalate bilayered cantilever to large deflections. A curvature of about 80 m−1 (radius of curvature of ∼1.2 cm) could be sensed under low frequency (3 Hz) bending motion. These results may pave the way for the development of low cost and easy to implement soft flexoelectric elastomer-based large curvature sensors on highly flexible metallic structures.
Published: 2017

33. Modeling of the multilevel conduction characteristics and fatigue profile of Ag/La1/3Ca2/3MnO3/Pt structures using a compact memristive approach

Author: W. Román Acevedo, Ulrike Lüders, Diego Rubi, Pablo Levy, P. Granell, Enrique Miranda, Jordi Suñé, Universidad Autónoma de Barcelona, Comisión Nacional de Energía Atómica [ARGENTINA] (CNEA), Universidad Nacional de San Martin (UNSAM), Laboratoire de Microélectronique et de Physique des Semiconducteurs (LaMIPS), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-NXP Semiconductors [France]-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de cristallographie et sciences des matériaux (CRISMAT), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), CONICET [PIP 291], CIC-Bs. As, ANPCyT [PICT2013 0788], Ministerio de Ciencia, Tecnologia e Innovacion Productiva, Argentina, DURSI of the Generalitat de Catalunya [2014SGR384], PANACHE-ENIAC, Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-NXP Semiconductors [France], Universitat Autònoma de Barcelona (UAB), Consejo Nacional de Investigaciones Científicas y Técnicas [Buenos Aires] (CONICET), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), and Instituto Nacional de Tecnología Industrial (INTI)
Subjects: Materials science, Modelos Electrónicos, Oxide, General Physics and Astronomy, Nanotechnology, purl.org/becyt/ford/2.2 [https], 02 engineering and technology, 01 natural sciences, 7. Clean energy, Pulsed laser deposition, chemistry.chemical_compound, 0103 physical sciences, Limit (music), [CHIM.CRIS]Chemical Sciences/Cristallography, [CHIM]Chemical Sciences, 010306 general physics, Memorias Resistivas, business.industry, Operator (physics), Manganitas, [CHIM.MATE]Chemical Sciences/Material chemistry, Dissipation, 021001 nanoscience & nanotechnology, Thermal conduction, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, purl.org/becyt/ford/2 [https], chemistry, Electrode, Optoelectronics, Memristors, 0210 nano-technology, business, Reduction (mathematics)
Abstract: The hysteretic conduction characteristics and fatigue profile of La1/3Ca2/3MnO3 (LCMO)-based memristive devices were investigated. The oxide films were grown by pulsed laser deposition (PLD) and sandwiched between Ag and Pt electrodes. The devices exhibit bipolar resistive switching (RS) effect with well-defined intermediate conduction states that arise from partial SET and RESET events. The current-voltage curves are modeled and simulated using a compact memristive approach. Two equations are considered: one for the electron transport based on the double-diode equation and the other for the memory state of the device driven by the play operator with logistic ridge functions. An expression that accounts for the remnant resistance of the device is obtained after simplifying the model equations in the low-voltage limit. The role played by the power dissipation in the LCMO reset dynamics as well as the asymmetrical reduction of the resistance window caused by long trains of switching pulses are discussed. Fil: Miranda, E.. Universidad Autonoma de Barcelona. Facultad de Física; España Fil: Roman Acevedo, Wilson Stibens. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes. Gerencia de Investigación y Aplicaciones; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Rubi, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes. Gerencia de Investigación y Aplicaciones; Argentina Fil: Lüders, U.. Centre National de la Recherche Scientifique; Francia. École Nationale Supérieure d'Ingénieurs de Caen; Francia Fil: Granell, Pablo Nicolás. Instituto Nacional de Tecnología Industrial. Centro de Micro y Nanoelectrónica del Bicentenario; Argentina Fil: Suñé, J.. Universidad Autonoma de Barcelona. Facultad de Física; España Fil: Levy, Pablo Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes. Gerencia de Investigación y Aplicaciones; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina
Published: 2017

34. Theoretical investigation of Vernier effect based sensors with hybrid porous silicon-polymer optical waveguides

Author: Mohammed Guendouz, Nathalie Lorrain, Paul Azuelos, Pauline Girault, Monique Thual, Luiz Poffo, Isabelle Hardy, Institut des Fonctions Optiques pour les Technologies de l'informatiON (Institut FOTON), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-École Nationale Supérieure des Sciences Appliquées et de Technologie (ENSSAT)-Centre National de la Recherche Scientifique (CNRS), Département Optique (IMT Atlantique - OPT), IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), École Nationale Supérieure des Sciences Appliquées et de Technologie (ENSSAT)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES), IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-École Nationale Supérieure des Sciences Appliquées et de Technologie (ENSSAT)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique)
Subjects: Detection limit, chemistry.chemical_classification, Materials science, business.industry, Single-mode optical fiber, General Physics and Astronomy, 02 engineering and technology, Polymer, 021001 nanoscience & nanotechnology, Porous silicon, 01 natural sciences, 010309 optics, Optics, chemistry, 0103 physical sciences, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Molecule, Sensitivity (control systems), Vernier effect, 0210 nano-technology, business, Biosensor
Abstract: International audience; A new combination of porous silicon and polymer optical waveguides is investigated for two different designs of Vernier effect based sensors for the surface detection of Bovine Serum Albumin molecules (BSA). The hybrid structures studied consist of two cascaded micro-resonators for one and a micro-resonator cascaded with a Mach-Zehnder for the other. Because of its high specific surface and bio-compatibility, we use porous silicon to implement the waveguides in the sensing part of the sensor into which BSA molecules are grafted. Polymer waveguides are then used for the reference part of the sensor because of their low optical losses. We consider the opto-geometric parameters of both waveguides for single mode propagation. Finally, optimized designs, taking into account standard experimental wavelength shift measurement limitation are presented for both structures. We demonstrate a theoretical Limit Of Detection (LOD) of 0.019 pg.mm-2 and a sensitivity of 12.5 nm/(pg.mm-2) with these hybrid sensors. To our knowledge, these values are lower by a factor of 8 for the LOD and higher, by a factor of 200 for the sensitivity, as compared to state of the art Vernier effect biosensors.
Published: 2017

35. Prediction of irradiation induced microstructures using a multiscale method coupling atomistic and phase field modeling: Application to the AgCu model alloy

Author: Vassilis Pontikis, Laurence Luneville, David Simeone, Gilles Demange, Groupe de physique des matériaux (GPM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), CEA- Saclay (CEA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), and Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS]Physics [physics], Physics, Condensed matter physics, Ion beam mixing, General Physics and Astronomy, 02 engineering and technology, Binary collision approximation, 021001 nanoscience & nanotechnology, Thermal diffusivity, Microstructure, 01 natural sciences, Molecular physics, Ion, Phase (matter), 0103 physical sciences, Irradiation, Diffusion (business), 010306 general physics, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS
Abstract: Microstructure patterning using the ion beam mixing process results from the competition between thermal diffusion and ballistic disordering induced by impinging ions. Although microstructure patterning under irradiation is now qualitatively understood, so far, no study could quantitatively estimate irradiation conditions leading to patterning. In this work, a new multiscale approach based on phase field was developed to simulate the microstructure evolution, and the occurrence of patterning due to ion irradiation in a silver-copper alloy, from atomic to microstructural scale. For that purpose, an efficient numerical scheme was developed to simulate the microstructure dynamics, within the framework of phase field. Equilibrium parameters of AgCu were computed using a mixed Monte Carlo-molecular dynamics approach. Ballistic effects induced by krypton ion irradiation, and point defect recreation leading to irradiation enhanced diffusion, were estimated using the binary collision approximation framework. As a...
Published: 2017

36. Stress-induced metallic behavior under magnetic field in Pr1−xCaxMnO3 (x=0.5 and 0.4) thin films (invited)

Author: Wilfrid Prellier, B. Raveau, Ph. Lecoeur, M. Hervieu, Anne-Marie Haghiri-Gosnet, B. Mercey, Ch. Simon, Damien Saurel, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Microstructures et de Microélectronique (L2M), and Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS]Physics [physics], Resistive touchscreen, Materials science, Magnetoresistance, Condensed matter physics, Doping, General Physics and Astronomy, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, Substrate (electronics), 021001 nanoscience & nanotechnology, 01 natural sciences, Magnetic field, Metal, Charge ordering, visual_art, 0103 physical sciences, visual_art.visual_art_medium, [CHIM]Chemical Sciences, Thin film, 010306 general physics, 0210 nano-technology, human activities
Abstract: We have investigated the role of the stress-induced by the presence of the substrate in thin films of colossal magnetoresistive manganites on structural, resistive and magnetic properties. Because of the strong coupling between the small structural distortions related to the charge-ordering (CO) and the resistive properties, the presence of the substrate prevents the full developpement of the charge ordering in Pr$_{0.5}$Ca$_{0.5}$MnO$_{3}$, especially in the very thin films. For thicker films, the CO state exists, but is not fully developped. Correlatively, the magnetic field which is necessary to suppress the CO is decreased drastically from 25 Tesla to about 5 Tesla on SrTiO$_{3}$ substrates. We have also investigated the influence of the doping level by studying the case of Pr$_{0.6}$Ca$_{0.4}$MnO$_{3}$.
Published: 2001

37. Growth and stress relaxation of Co/NiO bilayers on MgO(001)

Author: S. Dubourg, B. Warot, P. Baules, Etienne Snoeck, J.C. Ousset, Jean-François Bobo, Marie-José Casanove, Centre d'élaboration de matériaux et d'études structurales (CEMES), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Surfaces, Interfaces et Nano-Objets (CEMES-SINanO), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Laboratoire de Métallurgie Physique et Science des Matériaux (URA CNRS 155) (LMPSM), Université Henri Poincaré - Nancy 1 (UHP)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), and Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse)
Subjects: 010302 applied physics, Materials science, Non-blocking I/O, Analytical chemistry, General Physics and Astronomy, 02 engineering and technology, 021001 nanoscience & nanotechnology, Epitaxy, 01 natural sciences, Crystallography, Sputtering, 0103 physical sciences, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Surface roughness, Stress relaxation, 0210 nano-technology, High-resolution transmission electron microscopy, Layer (electronics), Deposition (chemistry), ComputingMilieux_MISCELLANEOUS
Abstract: Co/NiO bilayers have been grown on a MgO(001) surface in an ultrahigh vacuum sputtering chamber under various deposition conditions. Investigations by x-ray diffraction, atomic force microscopy, and high resolution transmission electron microscopy give evidence for a close relationship between structure and deposition conditions for the two different layers. The role of the deposition rate on the oxide layer surface roughness is particularly emphasized. At high deposition rates, surface roughness increases with temperature, whereas the surface remains flat for low deposition rates. Whatever the growth conditions, the NiO layer grows epitaxially on the MgO substrate with the orientation relationship NiO(001)[100]//MgO(001)[100]. The misfit strain (about 1%), elastically accommodated in the thinner layers (3 nm), is fully relaxed in 50-nm-thick layers. A temperature dependence of the cobalt layer structure is observed: at room temperature it grows in its high temperature face-centered cubic structure, where...
Published: 2001

38. Current crowding and 1/f noise in polycrystalline silicon thin film transistors

Author: Olivier Bonnaud, A. Mercha, L.K.J. Vandamme, Laurent Pichon, R Carin, Equipe Electronique - Laboratoire GREYC - UMR6072, Groupe de Recherche en Informatique, Image et Instrumentation de Caen (GREYC), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU), Department of Electrical Engineering, Technische Universiteit Eindhoven, Technische Universiteit Eindhoven (TU/e), Groupe de Microélectronique et Visualisation, Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS), Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), Université de Rennes (UR), and Integrated Circuits
Subjects: 010302 applied physics, Electron mobility, Materials science, Condensed matter physics, Infrasound, Current crowding, General Physics and Astronomy, Y-factor, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Noise (electronics), Cutoff frequency, 0103 physical sciences, Flicker noise, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, 0210 nano-technology, Electrical impedance
Abstract: Here we investigate dc characteristics, impedance versus frequency, and low frequency noise. The effect of current distribution on 1/f noise in polycrystalline silicon thin film transistors (TFTs) is discussed. We show that the channel impedance versus frequency roll induces spectra that could be misinterpreted above a corner frequency in terms of a frequency index ¿ in 1/f ^¿ with ¿ higher than 2. Moreover, ignoring the inhomogeneous current distribution leads to overestimation of the noise parameter. Whereas it seemed evident that the noise in TFTs can be interpreted in terms of carrier number fluctuation, the noise parameter variation versus the gate bias can be also understood in terms of mobility fluctuations by including the potential barrier evolution. ©2001 American Institute of Physics.
Published: 2001

39. How do shape anisotropy and spatial orientation of the constituents affect the permittivity of dielectric heterostructures?

Author: Abderrahmane Beroual, Christian Brosseau, A. Boudida, Laboratoire d'Electronique et Systèmes de Télécommunications (LEST), Université de Brest (UBO)-Ecole Nationale Supérieure des Télécommunications de Bretagne-Centre National de la Recherche Scientifique (CNRS), Centre de génie électrique de Lyon (CEGELY), Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-École Centrale de Lyon (ECL), Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon
Subjects: 010302 applied physics, Permittivity, Materials science, Condensed matter physics, Optical metrology, [SPI.NRJ]Engineering Sciences [physics]/Electric power, Isotropy, General Physics and Astronomy, Relative permittivity, Percolation theory, 02 engineering and technology, Dielectric, Computer simulation, 021001 nanoscience & nanotechnology, Thermal conduction, 01 natural sciences, Phase transitions, Dielectric properties, 0103 physical sciences, Heterostructures, 0210 nano-technology, Anisotropy, Integral equations, Critical exponent, Quasistatic process
Abstract: International audience; The study of dielectric heterostructures has been advancing at a rapid pace. Much of the interest in these materials stems from the fact that their physical properties can be systematically tuned by variation of the size and shape of the constituents. Here we report on extensive computer simulations of the effective permittivity of dielectric periodic (deterministic) heterostructures, having monosized hard core inclusions of anisotropic shape (rod, ellipsoid) embedded in an otherwise homogeneous and isotropic matrix. The real and imaginary parts of the permittivity, in the quasistatic limit, are rigorously evaluated with the use of the PHI3D field calculation package and the resolution of boundary integral equations. In this article, we show that the effective permittivity has critical properties near a conduction threshold. The conduction threshold concentration can be significantly modified by the size, shape, and spatial arrangement of the constituents. More specifically, it obeys a square law dependence as a function of the aspect ratio, i.e., the ratio of the smaller dimension to the larger dimension in both the rodlike and ellipsoidal inclusions. The data exhibit a scaling behavior and can all be collapsed onto a single master curve, indicative of a remarkable universality in the conductivity property. The critical exponents which determine how the real and imaginary parts of the effective permittivity scale with the distance from the conduction threshold are determined. Our results are compared with the scaling prediction of the standard percolation theory for infinite three-dimensional random lattices of insulator–normal metal composite systems. We also observed that the conduction transition is shifted towards higher concentrations as the angle between the symmetry axis and the direction of the applied electric field increases. Increasing the contrast ratio, between the permittivity and the conductivity of the background medium and the inclusions, results in dramatic changes of the complex effective permittivity, depending on the geometry of the inclusions. The scale-dependent properties and the mechanism which govern criticality are related to the actual area of contacts between the inclusions.
Published: 2000

40. Surface effects on current mechanisms in 6H-SiC n+pp+ structures passivated with a deposited oxide

Author: Jean-Pierre Chante, Sylvie Ortolland, A. Senes, Marie-Laure Locatelli, Christophe Raynaud, Centre de génie électrique de Lyon (CEGELY), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), and Ampère, Publications
Subjects: DEVICES, Materials science, Optical beam-induced current, Passivation, Analytical chemistry, Oxide, General Physics and Astronomy, chemistry.chemical_element, FREQUENCY, 7. Clean energy, 01 natural sciences, Capacitance, Carbide, 010309 optics, chemistry.chemical_compound, 0103 physical sciences, VOLTAGE, DIODES, Diode, 010302 applied physics, business.industry, [SPI.NRJ]Engineering Sciences [physics]/Electric power, TRAPS, Atmospheric temperature range, Nitrogen, CARBIDE, CAPACITANCE, chemistry, Optoelectronics, business, [SPI.NRJ] Engineering Sciences [physics]/Electric power
Abstract: International audience; Bipolar n(+)pp(+) diodes fabricated by nitrogen implantation and passivated with a deposited oxide have been characterized. Current-voltage measurements in a large temperature range have been analyzed. We also used the optical beam induced current method to represent the depleted zone at the surface around a reverse-biased device. We show that phenomena as the diameter-dependent current for low reverse and forward biases, the specific value for the energy activation of current under low bias equal to 0.65 eV, the reverse current-voltage characteristics evolution with time, or the anomalous spread of the depleted layer around a reverse-biased diode can be correlated with the presence of the deposited oxide as a passivation layer. A study of the current-time characteristic, obtained for a set reverse bias, is used to prove the presence of charges in the oxide and interface states responsible for an eventual inversion channel along the mesa. (C) 1998 American Institute of Physics.
Published: 1998

41. Solid state interdiffusions in epitaxial Fe/GaAs(001) heterostructures during ultrahigh vacuum annealings up to 450 °C

Author: Roland Guérin, Guy Jézéquel, Stéphanie Députier, J. Crestou, André Rocher, C. Cohen, Bruno Lépine, A. Filipe, F. Abel, S. Ababou, A. Guivarc'h, Alain Schuhl, Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Milieux Environnementaux, Transferts et Interactions dans les hydrosystèmes et les Sols (METIS), Université Pierre et Marie Curie - Paris 6 (UPMC)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique des matériaux (LPM), Université Henri Poincaré - Nancy 1 (UHP)-Institut National Polytechnique de Lorraine (INPL)-Centre National de la Recherche Scientifique (CNRS), Institut des Nanosciences de Paris (INSP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Groupe de Physique des Solides (GPS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-École pratique des hautes études (EPHE), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)
Subjects: [PHYS]Physics [physics], 010302 applied physics, Materials science, Condensed matter physics, Annealing (metallurgy), Alloy, General Physics and Astronomy, Heterojunction, 02 engineering and technology, engineering.material, Atmospheric temperature range, 021001 nanoscience & nanotechnology, Epitaxy, 01 natural sciences, Gallium arsenide, Crystallography, Magnetization, chemistry.chemical_compound, chemistry, 0103 physical sciences, engineering, Antiferromagnetism, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 0210 nano-technology
Abstract: International audience; We have used a set of complementary experimental techniques to characterize an epitaxial structure (25 nm Fe)/GaAs(001) annealed at 450 °C under ultrahigh vacuum conditions. The solid state interdiffusion leads to the formation of an epitaxial reaction layer made of Fe2As patches embedded in a Ga rich Fe3Ga2−XAsX ternary phase. The epitaxial character of this layer explains how the usually reported epitaxial growth of Fe on GaAs performed in the temperature range of 175 to 225 °C is possible in spite of the species intermixing occurring at the interface. Moreover, the observed grains of Fe2As explain the decrease of magnetization at the interface in such contact, since Fe2As is an antiferromagnetic alloy.
Published: 1998

42. Screening magnetic fields by superconductors: A simple model

Author: Yohann Thimont, Laura Gozzelino, P. Bernstein, Roberto Gerbaldo, Francesco Laviano, Jacques G. Noudem, Gianluca Ghigo, Jean-Guy Caputo, Centre National de la Recherche Scientifique - CNRS (FRANCE), Ecole Nationale Supérieure d'Ingénieurs de Caen - ENSICAEN (FRANCE), Institut National des Sciences Appliquées de Rouen - INSA (FRANCE), Université de Caen Basse-Normandie (FRANCE), Politecnico di Torino (ITALY), Laboratoire de Cristallographie et Sciences des Matériaux - CRISMAT (Caen, France), Laboratoire de Mathématiques de l'INSA de Rouen Normandie (LMI), Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU), Laboratoire de cristallographie et sciences des matériaux (CRISMAT), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), Department of Applied Science and Technology [Politecnico di Torino] (DISAT), Politecnico di Torino = Polytechnic of Turin (Polito), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Universitaire des Sciences Appliquées de Cherbourg (LUSAC), and Normandie Université (NU)-Normandie Université (NU)
Subjects: Matériaux, General Physics and Astronomy, Flux, 02 engineering and technology, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, [SPI]Engineering Sciences [physics], Condensed Matter::Superconductivity, 0103 physical sciences, Superconductors, 010306 general physics, Variable (mathematics), Physics, Superconductivity, [PHYS]Physics [physics], [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, Milieux fluides et réactifs, 021001 nanoscience & nanotechnology, Magnetic field, Computational physics, London equations, Line (geometry), [SDE]Environmental Sciences, 0210 nano-technology, Distribution (differential geometry), Vector potential
Abstract: International audience; We introduce a simple approach to evaluate the magnetic field distribution around superconducting samples, based on the London equations; the elementary variable is the vector potential. This procedure has no adjustable parameters, only the sample geometry and the London length, λ, determine the solution. This approach was validated by comparing the induction field calculated to the one measured above MgB2 disks of different diameters, at 20 K and for applied fields lower than 0.4 T. The model can be applied if the flux line penetration inside the sample can be neglected when calculating the induction field distribution outside the superconductor. We conclude by showing on a cup-shape geometry how one can design a magnetic shield satisfying a specific constraint.
Published: 2013

43. Substrate effects on the room-temperature ferromagnetism in Co-doped TiO_2 thin films grown by pulsed laser deposition

Author: Wilfrid Prellier, Hoa Hong Nguyen, Antoine Ruyter, Joe Sakai, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Ecotoxicologie - Milieux Aquatiques (LEMA), Université Le Havre Normandie (ULH), Normandie Université (NU)-Normandie Université (NU), Laboratoire d'Electrodynamique des Matériaux Avancés (LEMA), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Tours (UT)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS]Physics [physics], Anatase, Laser ablation, Materials science, Analytical chemistry, General Physics and Astronomy, [CHIM.MATE]Chemical Sciences/Material chemistry, Coercivity, Pulsed laser deposition, Magnetization, Nuclear magnetic resonance, Ferromagnetism, Curie temperature, [CHIM]Chemical Sciences, Thin film
Abstract: Co:TiO_2 films were fabricated by laser ablation on Si, LaAlO_3 (LAO), and SrTiO_3 (STO) substrates from a ceramic target. Films on all types of substrates have Curie temperature (T_C) above 400 K. All films are highly crystallized with different structures. While films on Si substrates are rutile, films on LAO and STO substrates are single phased anatase. Due to the different lattice mismatch, films grown under the same growth conditions on Si, LAO, and STO substrates have different saturation magnetization and coercivity. While Co atoms are mostly localized near the surface of the films, magnetic measurements suggested that the ferromagnetism unlikely originates from Co clusters.
Published: 2004

44. Static electric field enhancement in nanoscale structures

Author: Maykel Márquez-Mijares, Didier Lemoine, Bruno Lepetit, Théorie (LCAR), Laboratoire Collisions Agrégats Réactivité (LCAR), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Instituto Superior de Tecnologias y Ciencias Aplicadas - InSTEC (CUBA), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse)
Subjects: [PHYS]Physics [physics], Materials science, Condensed matter physics, Field (physics), General Physics and Astronomy, chemistry.chemical_element, 02 engineering and technology, Tungsten, 021001 nanoscience & nanotechnology, 01 natural sciences, Power law, Characterization (materials science), Field electron emission, Atomic radius, chemistry, Electric field, 0103 physical sciences, Density functional theory, Atomic physics, 010306 general physics, 0210 nano-technology
Abstract: International audience; We study the effect of local atomic- and nano-scale protrusions on field emission and, in particular, on the local field enhancement which plays a key role as known from the Fowler-Nordheim model of electronic emission. We study atomic size defects which consist of right angle steps forming an infinite length staircase on a tungsten surface. This structure is embedded in a 1 GV/m ambient electrostatic field. We perform calculations based upon density functional theory in order to characterize the total and induced electronic densities as well as the local electrostatic fields taking into account the detailed atomic structure of the metal. We show how the results must be processed to become comparable with those of a simple homogeneous tungsten sheet electrostatic model. We also describe an innovative procedure to extrapolate our results to nanoscale defects of larger sizes, which relies on the microscopic findings to guide, tune, and improve the homogeneous metal model, thus gaining predictive power. Furthermore, we evidence analytical power laws for the field enhancement characterization. The main physics-wise outcome of this analysis is that limited field enhancement is to be expected from atomic- and nano-scale defects.
Published: 2016

45. Polarized Raman backscattering selection rules for (hhl)-oriented diamond- and zincblende-type crystals

Author: Julian A. Steele, Pascal Puech, Roger A Lewis, University of Wollongong [Australia], Centre for Surface Chemistry and Catalysis, Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Matériaux Multi-fonctionnels et Multi-échelles (CEMES-M3), Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)
Subjects: Raman scattering, Nanostructure, Materials science, Degrees of freedom (statistics), General Physics and Astronomy, 02 engineering and technology, Orientation dependent, Backscattering, engineering.material, 01 natural sciences, Degrees of freedom (mechanics), Zinc sulfide, Crystal, symbols.namesake, Optics, Raman backscattering, 0103 physical sciences, Selection Rules, 010306 general physics, Condensed matter physics, business.industry, Scattering, Diamond, Wide band gap semiconductors, 021001 nanoscience & nanotechnology, Orientation (vector space), Semiconductor crystals, Semiconductor, Crystal surfaces, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], engineering, symbols, Polarized micro-Raman, Polarized Raman, Local orientations, 0210 nano-technology, Raman spectroscopy, business, Crystal orientation
Abstract: Due to their interesting orientation-dependent properties, the ability to grow high-index semiconductor crystals and nanostructures extends the design palette for applications based on these materials. Notably, a source containing a systematic reporting of what the Raman tensors are for an arbitrary high-index zincblende material is yet to appear in the literature. Herein, we present the polarized Raman backscattering selection rules for arbitrary (hhl)-oriented diamond- and zincblende-type crystal surfaces and verify their correctness through experiment (up to (115)). Considering the many degrees of freedom available to common polarized micro-Raman scattering instruments, and the unique local orientation of the probed material, we further examine a range of consequences imposed by the selection rules for the Raman backscattering method. ispartof: Journal of Applied Physics vol:120 issue:5 status: published
Published: 2016

46. Temperature stability of (Pt/Co)3/IrMn multilayers

Author: F. Letellier, L. Lechevallier, A. Zarefy, B. Dieny, Didier Blavette, Vincent Baltz, Rodrigue Lardé, B. Rodmacq, J.M. Le Breton, Groupe de physique des matériaux (GPM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), and Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Self-diffusion, Materials science, Annealing (metallurgy), Bilayer, Stacking, Analytical chemistry, General Physics and Astronomy, 02 engineering and technology, Atom probe, 021001 nanoscience & nanotechnology, 01 natural sciences, law.invention, Crystallography, law, Structural stability, 0103 physical sciences, Thermal stability, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 010306 general physics, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS, Phase diagram
Abstract: The effect of annealing on the structural stability of (Pt2nm/Co0.4 nm)3/IrMn7nm multilayers has been investigated using atom probe tomography. The composition of individual layers was measured after annealing at 300, 400, 500, and 700 °C. While results show that the (Pt/Co)3/IrMn stacking sequence is preserved up to 400 °C, there is an almost complete destruction of the multilayered structure when annealing at higher temperatures (500 and 700 °C). Co layers no more alternate with Pt-rich layers. The whole stack is transformed into an IrCo/PtMn bilayer. These results are interpreted on the basis of atomic mobilities and chemical affinities. Diffusion of Co and Mn is shown to become important when annealing temperature approaches 500 °C. Results are well accounted for by thermodynamics arguments considering the Co-Ir and Pt-Mn phase diagrams.
Published: 2012
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47. Quantitative analysis of doped/undoped ZnO nanomaterials using laser assisted atom probe tomography: Influence of the analysis parameters

Author: Corine Sartel, Lorenzo Mancini, Xavier Portier, Said Hassani, Vincent Sallet, Nooshin Amirifar, Jonathan Houard, Lorenzo Rigutti, Ahmed Ziani, Celia Castro, Emir Zehani, Etienne Talbot, Rodrigue Lardé, Philippe Pareige, Groupe de physique des matériaux (GPM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), Groupe d'Etude de la Matière Condensée (GEMAC), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), Centre de recherche sur les Ions, les MAtériaux et la Photonique (CIMAP - UMR 6252), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Caen Normandie (UNICAEN), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), and Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, General Physics and Astronomy, Nanotechnology, 02 engineering and technology, Atom probe, 01 natural sciences, law.invention, Nanomaterials, Condensed Matter::Materials Science, law, 0103 physical sciences, Physics::Atomic and Molecular Clusters, Microelectronics, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], 010302 applied physics, business.industry, Doping, 021001 nanoscience & nanotechnology, Laser, Evaporation (deposition), Semiconductor, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Atom optics, Optoelectronics, 0210 nano-technology, business
Abstract: International audience; In the last decade, atom probe tomography has become a powerful tool to investigate semiconductor and insulator nanomaterials in microelectronics, spintronics, and optoelectronics. In this paper, we report an investigation of zinc oxide nanostructures using atom probe tomography. We observed that the chemical composition of zinc oxide is strongly dependent on the analysis parameters used for atom probe experiments. It was observed that at high laser pulse energies, the electric field at the specimen surface is strongly dependent on the crystallographic directions. This dependence leads to an inhomogeneous field evaporation of the surface atoms, resulting in unreliable measurements. We show that the laser pulse energy has to be well tuned to obtain reliable quantitative chemical composition measurements of undoped and doped ZnO nanomaterials.
Published: 2015

48. An ordered Ga2Te3phase in the ZnTe/GaSb interface

Author: DA Ashenford, B. Lunn, CT Chou, M.‐J. Casanove, John L. Hutchison, David Cherns, John W Steeds, Roger Vincent, RainDance Technologies [Billerica, MA, USA], inconnu, Inconnu, Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Surfaces, Interfaces et Nano-Objets (CEMES-SINanO), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3)
Subjects: 010302 applied physics, Nanostructure, Chemistry, General Physics and Astronomy, Heterojunction, 02 engineering and technology, Crystal structure, engineering.material, 021001 nanoscience & nanotechnology, 01 natural sciences, Crystallography, Sphalerite, Electron diffraction, Lattice (order), 0103 physical sciences, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], engineering, Regular array, Orthorhombic crystal system, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS
Abstract: A Ga2Te3 interfacial phase has been observed in a ZnTe/(001)GaSb heterostructure by high resolution electron microscopy under special imaging conditions. This phase exists in domains 5–10 nm in size on the ZnTe side of, and usually 2–4 nm away from, the interface. A structural model has been proposed for this phase that is derived from the sphalerite cell with cation sites occupied either fully (occupancy 1) or partially (occupancy 5/9) by Ga atoms. The fully occupied Ga sites form a regular array of uninterrupted chains along the [110] direction of the sphalerite unit cell. The partially occupied Ga sites can also be considered as forming chains containing both Ga atoms and vacancies along the [110] direction. Within these chains vacancies are highly mobile, resulting in an average Ga occupancy of 5/9. The unit cell of Ga2Te3 is orthorhombic with the space group Amm2. The lattice parameters of the unit cell have been derived from electron diffraction data.
Published: 1993

49. Magnetic anisotropy determination and magnetic hyperthermia properties of small Fe nanoparticles in the superparamagnetic regime

Author: B. Mehdaoui, A. Meffre, Sébastien Lachaize, Lise-Marie Lacroix, Julian Carrey, Bruno Chaudret, Marc Respaud, Michel Gougeon, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - INPT (FRANCE), Institut National des Sciences Appliquées de Toulouse - INSA (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre interuniversitaire de recherche et d'ingenierie des matériaux (CIRIMAT), Université de Toulouse (UT), Laboratoire de chimie de coordination (LCC), Institut de Chimie de Toulouse (ICT), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Institut Carnot Chimie Balard Cirimat, Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), and Université de Montpellier (UM)
Subjects: Condensed Matter - Materials Science, Materials science, Matériaux, Analytical chemistry, General Physics and Astronomy, Specific absorption rate, Nanoparticle, Materials Science (cond-mat.mtrl-sci), FOS: Physical sciences, [CHIM.MATE]Chemical Sciences/Material chemistry, Power law, [SPI.MAT]Engineering Sciences [physics]/Materials, Magnetic field, Magnetic anisotropy, Magnetic hyperthermia, Anisotropy, Superparamagnetism
Abstract: We report on the magnetic and hyperthermia properties of iron nanoparticles synthesized by organometallic chemistry. They are 5.5 nm in diameter and display a saturation magnetization close to the bulk one. Magnetic properties are dominated by the contribution of aggregates of nanoparticles with respect to individual isolated nanoparticles. Alternative susceptibility measurements are been performed on a low interacting system obtained after eliminating the aggregates by centrifugation. A quantitative analysis using the Gittleman s model allow a determination of the effective anisotropy Keff = 1.3 * 10^5 J.m^{-3}, more than two times the magnetocristalline value of bulk iron. Hyperthermia measurements are performed on agglomerates of nanoparticles at a magnetic field up to 66 mT and at frequencies in the range 5-300 kHz. Maximum measured SAR is 280 W/g at 300 kHz and 66 mT. Specific absorption rate (SAR) displays a square dependence with the magnetic field below 30 mT but deviates from this power law at higher value. SAR is linear with the applied frequency for mu_0H=19 mT. The deviations from the linear response theory are discussed. A refined estimation of the optimal size of iron nanoparticles for hyperthermia applications is provided using the determined effective anisotropy value.
Published: 2010

50. Structural, magnetic, transport, and magneto-optical properties of single crystal La2/3Sr1/3MnO3 thin films

Author: P. Baules, Ch. Roucau, Jean-François Bobo, J.C. Ousset, Marie-José Casanove, Albert Fert, R. Porres, D. Magnoux, Bertrand Raquet, Etienne Snoeck, Laboratoire de Métallurgie Physique et Science des Matériaux (URA CNRS 155) (LMPSM), Université Henri Poincaré - Nancy 1 (UHP)-Centre National de la Recherche Scientifique (CNRS), Unité mixte de physique CNRS/Thales (UMPhy CNRS/THALES), THALES [France]-Centre National de la Recherche Scientifique (CNRS), Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Surfaces, Interfaces et Nano-Objets (CEMES-SINanO), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), THALES-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3)
Subjects: 010302 applied physics, Materials science, Kerr effect, Magnetoresistance, Condensed matter physics, General Physics and Astronomy, 02 engineering and technology, Sputter deposition, Coercivity, 021001 nanoscience & nanotechnology, 01 natural sciences, 0103 physical sciences, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Curie temperature, Grain boundary, Thin film, 0210 nano-technology, Single crystal, ComputingMilieux_MISCELLANEOUS
Abstract: We have grown La0.7Sr0.3MnO3 thin films by reactive facing target radio frequency sputtering on SrTiO3 (001) substrates with the nominal stoichiometry and the perovskite structure down to nanometer-scale film thickness. The films are found to be perfectly expitaxied on SrTiO3, without misfit dislocations. The surfaces of the layers were found to be highly flat with terraces of ≈4 A height corresponding to the manganite unit cell. Magnetic measurements evidence a decrease of the Curie temperature for decreasing thickness. Low temperature magnetoresistance is very small, confirming the absence of grain boundaries in the films but it reaches ≈−50% at room temperature. Finally, magneto-optical Kerr effect measurements between 20 and 400 K reveal the onset of ferromagnetic transition via the coercive field increase and the Kerr rotation and ellipticity measurements.
Published: 2000

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