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Start Over Author "Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS)" Topic 0210 nano-technology
192 results on '"Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS)"'

1. Modelling of ultrasound transmission through a solid-liquid interface comprising a network of gas pockets

Author

Gilles Corneloup, Francois Baque, Dominique Chatain, Joseph Moysan, Kevin Paumel, Service de Technologie des Composants et des Procédés (STCP), Département Technologie Nucléaire (DTN), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Caractérisation Non Destructive [Aix en Provence] (LCND), MISTRAL-Lab, CEA Cadarache, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ), Ondes et Imagerie ( O&I ), Laboratoire de Mécanique et d'Acoustique [Marseille] ( LMA ), Aix Marseille Université ( AMU ) -Ecole Centrale de Marseille ( ECM ) -Centre National de la Recherche Scientifique ( CNRS ) -Aix Marseille Université ( AMU ) -Ecole Centrale de Marseille ( ECM ) -Centre National de la Recherche Scientifique ( CNRS ), Centre de recherche de la matière condensée et des nanosciences ( CRMCN ), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique ( CNRS ), and Département Technologie Nucléaire ( DTN )

Subjects
Materials science, Analytical chemistry, General Physics and Astronomy, 02 engineering and technology, Surface finish, ultrasounds, 01 natural sciences, Nondestructive testing, 0103 physical sciences, Surface roughness, sodium fast reactor, Transmission coefficient, Composite material, 010301 acoustics, [ PHYS.MECA.ACOU ] Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], non destructive testing, wetting, business.industry, Ultrasonic testing, technology, industry, and agriculture, 021001 nanoscience & nanotechnology, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], Transducer, Computer Science::Graphics, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], interface, Ultrasonic sensor, spring model, Wetting, 0210 nano-technology, business
Abstract

International audience; Ultrasonic inspection of sodium-cooled fast reactor requires a good acoustic coupling between the transducer and the liquid sodium. Ultrasonic transmission through a solid surface in contact with liquid sodium can be complex due to the presence of microscopic gas pockets entrapped by the surface roughness. Experiments are run using substrates with controlled roughness consisting of a network of holes and a modeling approach is then developed. In this model, a gas pocket stiffness at a partially solid-liquid interface is defined. This stiffness is then used to calculate the transmission coefficient of ultrasound at the entire interface. The gas pocket stiffness has a static, as well as an inertial component, which depends on the ultrasonic frequency and the radiative mass.

Published
2011

2. In situ study of the quasicrystal growth by synchrotron X-ray imaging

Author

José Baruchel, Thomas Schenk, P. Pino, Nathalie Mangelinck-Noël, H. Nguyen-Thi, J. Gastaldi, G. Reinhart, A. Buffet, H. Klein, H. Jung, Benjamin Grushko, B. Przepiarzynski, Jürgen Härtwig, Bernard Billia, Centre de recherche de la matière condensée et des nanosciences ( CRMCN ), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique ( CNRS ), Laboratoire matériaux et microélectronique de Provence ( L2MP ), Université Paul Cézanne - Aix-Marseille 3-Université de Provence - Aix-Marseille 1-Université de Toulon ( UTLN ) -Centre National de la Recherche Scientifique ( CNRS ), ESRF, IFF, FZ Juelich, Laboratoire de Cristallographie CNRS, Grenoble, Université de Lille, Sciences Humaines et Sociales, European Synchrotron Radiation Facility ( ESRF ), IFF, Forschungszentrum Juelich, Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), Laboratoire matériaux et microélectronique de Provence (L2MP), Université Paul Cézanne - Aix-Marseille 3-Université de Provence - Aix-Marseille 1-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), European Synchrotron Radiation Facility (ESRF), Matériaux, Rayonnements, Structure (NEEL - MRS), Institut Néel (NEEL), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), and Matériaux, Rayonnements, Structure (MRS)

Subjects
Alloy, Oxide, 02 engineering and technology, engineering.material, 01 natural sciences, law.invention, chemistry.chemical_compound, Optics, law, Lattice (order), 0103 physical sciences, 010306 general physics, Supercooling, [PHYS]Physics [physics], [ PHYS ] Physics [physics], Condensed matter physics, business.industry, Quasicrystal, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Synchrotron, Semiconductor, chemistry, Quasiperiodic function, Physical Sciences, engineering, 0210 nano-technology, business
Abstract

International audience; One of the main challenges of the quasicrystal science is to elucidate how the quasiperiodic order can extend so far, i.e. up to several centimeters according to the size of the single grains of various alloys routinely grown nowadays [1, 2, 3]. Noticing that most of the present knowledge on the growth of quasicrystal grains has been collected after their cooling at room temperature, we have carried out the first in situ and real time observation of this peculiar process which has clearly disclosed both, the shape of the growing interface and its defective state. Therefore we have studied the solidification of an AlPdMn alloy giving quasicrystal grains by synchrotron X-ray imaging, combining thereby the radiography and X-ray topography techniques. Radiography allowed us to clearly evidence a facetted growth proceeding by lateral motion of ledges at the solid-melt interface and controlled by the interface kinetics rather than by the local heat flow as widely thought. Thus a realistic estimate of the kinetic coefficient was deduced from the solid-melt interface undercooling which indicates that the quasicrystal growth is more likely comparable to both semiconductor and oxide growths than to pure metal growth. The X-ray topographs recorded simultaneously with radiographs, revealed that a lot of strains and defects are generated in the quasicrystal grains during their growth, which could be related to the growth process itself and very informative on the origin of the stability of the quasicrystal lattice.

Published
2007

3. The Samson phase, β-Mg2Al3, revisited

Author

Stefan Brühne, J. P. A. Makongo, Françoise Bley, Nathalie Mangelinck-Noël, Stefan Hoffmann, Daniel C. Fredrickson, Yuri Grin, Thomas Proffen, Jean Louis Chemin, C. Thomas, Volker Gramlich, Raul Cardoso, Thomas P. Weber, Bernard Billia, Henri Nguyen-Thi, Janusz J. Malinowski, Beata Dubiel, Jeppe Christensen, Guido Kreiner, Wieslawa Sikora, Sven Lidin, Marc de Boissieu, Aleksandra Czyrska-Filemonowicz, Anna Zielińska-Lipiec, Jürgen Schreuer, Jean Marc Joubert, Wilder Carrillo-Cabrera, Michael Feuerbacher, Walter Steurer, G. Krauss, Thomas Schenk, Wolf Assmus, Patricia Donnadieu, Marek Mihalkovic, Philippe Schaub, J. Gastaldi, Forschungszentrum Jülich GmbH, Max Planck Institute for Chemical Physics of Solids, Laboratoire de Chimie Metallurgique des Terres Rares ( UPR 209 ), ISCSA-CNRS, Ecole Nationale Supérieure des Mines de Nancy ( ENSMN ), Institut Mines-Télécom [Paris]-Université de Lorraine ( UL ), Centre de recherche de la matière condensée et des nanosciences ( CRMCN ), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique ( CNRS ), Laboratoire matériaux et microélectronique de Provence ( L2MP ), Université Paul Cézanne - Aix-Marseille 3-Université de Provence - Aix-Marseille 1-Université de Toulon ( UTLN ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de thermodynamique et physico-chimie métallurgiques ( LTPCM ), Institut National Polytechnique de Grenoble ( INPG ) -Centre National de la Recherche Scientifique ( CNRS ), Faculty of metals engineering and industrial computer science, Swiss Federal Institute of Technology in Zürich ( ETH Zürich ), Department of Physical, Inorganic and Structural Chemistry ( Arrhenius Laboratory ), Stockholm University, Arrhenius Laboratory, Insitute of physics, Slovak Academy of Science, Faculty of Physics and Applied Computer Science [Kraków] ( FPACS ), AGH University of Science and Technology, Physikalisches Institut [Frankfurt/Main], Goethe-Universität Frankfurt am Main, Los Alamos Natl Lab, Los Alamos, NM 87545 USA, Insitut fur Geowissenschaften, Universitet Frankfurt, Forschungszentrum Jülich GmbH | Centre de recherche de Juliers, Helmholtz-Gemeinschaft = Helmholtz Association, Max Planck Institute for Chemical Physics of Solids (CPfS), Max-Planck-Gesellschaft, Chimie métallurgique des terres rares (CMTR), Centre National de la Recherche Scientifique (CNRS), Ecole Nationale Supérieure des Mines de Nancy (ENSMN), Institut Mines-Télécom [Paris] (IMT)-Université de Lorraine (UL), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), Laboratoire matériaux et microélectronique de Provence (L2MP), Université Paul Cézanne - Aix-Marseille 3-Université de Provence - Aix-Marseille 1-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de thermodynamique et physico-chimie métallurgiques (LTPCM), Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Department of Physical, Inorganic and Structural Chemistry (Arrhenius Laboratory), Faculty of Physics and Applied Computer Science [Kraków] (FPACS), AGH University of Science and Technology [Krakow, PL] (AGH UST), Los Alamos National Laboratory (LANL), and Institut für Geowissenschaften [Frankfurt am Main]

Subjects
Phase transition, 02 engineering and technology, Crystal structure, Magnesium aluminides, CMA, Samson phase, 01 natural sciences, Molecular physics, Thermal expansion, Inorganic Chemistry, Elastic parameters, Phase (matter), 0103 physical sciences, Electron microscopy, General Materials Science, Microstructure, ComputingMilieux_MISCELLANEOUS, Phase diagram, 010302 applied physics, Chemistry, Space group, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Powder diffraction structure analysis, X-ray diffraction, Crystallography, Reciprocal lattice, [ CHIM.MATE ] Chemical Sciences/Material chemistry, X-ray crystallography, 0210 nano-technology
Abstract

Co-Authors: Michael Feuerbacher, Carsten Thomas, Julien P. A. Makongo, Stefan Hoffmann, Wilder Carrillo-Cabrera, Raul Cardoso, Yuri Grin, Guido Kreiner, Jean-Marc Joubert, Thomas Schenk, Joseph Gastaldi, Henri Nguyen-Thi, Nathalie Mangelinck-Noël, Bernard Billia, Patricia Donnadieu, Aleksandra Czyrska-Filemonowicz, Anna Zielinska-Lipiec, Beata Dubiel, Thomas Weber, Philippe Schaub, Günter Krauss, Volker Gramlich, Jeppe Christensen, Sven Lidin, Daniel Fredrickson, Marek Mihalkovic, Wieslawa Sikora, Janusz Malinowski, Stefan Brühne, Thomas Proffen, Wolf Assmus, Marc de Boissieu, Francoise Bley, Jean-Luis Chemin, Jürgen Schreuer Abstract. The Al−Mg phase diagram has been reinvestigated in the vicinity of the stability range of the Samson phase, β-Mg2Al3 (cF1168). For the composition Mg 38.5 Al 61.5, this cubic phase, space group Fd-3m (no 227), a = 28.242(1) Å, V = 22526(2) Å3, undergoes at 214 °C a first-order phase transition to rhombohedral β′-Mg2Al3(hR293), a = 19.968(1) Å, c = 48.9114(8) Å, V = 16889(2) Å3, (i.e. 22519 Å3 for the equivalent cubic unit cell) space group R3m (no 160), a subgroup of index four of Fd-3m. The structure of the β-phase has been redetermined at ambient temperature as well as in situ at 400 °C. It essentially agrees with Samson's model, even in most of the many partially occupied and split positions. The structure of β′-Mg2Al3is closely related to that of the β-phase. Its atomic sites can be derived from those of the β-phase by group-theoretical considerations. The main difference between the two structures is that all atomic sites are fully occupied in case of the β′-phase. The reciprocal space, Bragg as well as diffuse scattering, has been explored as function of temperature and the β- to β′-phase transition was studied in detail. The microstructures of both phases have been analyzed by electron microscopy and X-ray topography showing them highly defective. Finally, the thermal expansion coefficients and elastic parameters have been determined. Their values are somewhere in between those of Al and Mg.

Published
2007

4. Heptane Adsorption in Silicalite-1: Neutron Scattering Investigation

Author

J. P. Coulomb, N. Floquet, Gilles Andre, Jean-Marc Simon, Guy Weber, J. P. Bellat, Simon, Jean-Marc, Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), Centre de recherche de la matière condensée et des nanosciences ( CRMCN ), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique ( CNRS ), Laboratoire Interdisciplinaire Carnot de Bourgogne ( LICB ), Université de Bourgogne ( UB ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire Léon Brillouin ( LLB - UMR 12 ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ), Cinam, Hal, Laboratoire Interdisciplinaire Carnot de Bourgogne (LICB), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS), 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, Laboratoire Interdisciplinaire Carnot de Bourgogne (ICB), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

Subjects
Heptane, Phase transition, Chemistry, Rietveld refinement, Neutron diffraction, Thermodynamics, 02 engineering and technology, Neutron scattering, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, chemistry.chemical_compound, Crystallography, [CHIM.THEO] Chemical Sciences/Theoretical and/or physical chemistry, General Energy, Adsorption, Deuterium, [ CHIM.THEO ] Chemical Sciences/Theoretical and/or physical chemistry, Molecule, Physical and Theoretical Chemistry, 0210 nano-technology
Abstract

International audience; Structural properties of confined deuterated n-heptane in silicalite-1 have been investigated by neutron scattering experiments during the adsorption process. At 300 K, the adsorption isotherm shows a sharp inflection at a loading near Nads ) 4 molecules per silicalite-1 unit cell. In addition, the diffusivities obtained from recent QENS data exhibit a loading dependence. Our motivation is to find structural signatures of the peculiar behavior of n-heptane in silicalite-1 and to check the numerous computer simulation findings of this behavior. Our detailed neutron diffraction investigation agrees with the MONO-ORTHO phase transition of the silicalite-1 above a Nads value of 4 molecules per unit cell, while no transition is reported for the n-hexane/silicalite-1 system at 300 K. Besides, the adsorption of C7D16 molecules in silicalite-1 is proved to be a two-step filling process. The location of the C7D16 molecules at increasing loading obtained from Rietveld refinement shows that the C7D16 molecules begin by first filling the straight channels, then near Nads ) 4 mol./u.c., C7D16 molecules fill both straight and sinusoidal channels. Our structural results happen to be in agreement with computer simulation calculations newly reported by Song et al. By contrast, the commensurate “freezing” of n-heptane in the sinusoidal channels of the silicalite-1 obtained from molecular simulation does not explain the two-step adsorption process. Rather, it corresponds to the final adsorption state similar to the molecular arrangement determined for the 8 n-hexane/silicalite-1 complex at 180 K. Recent thermodesorption studies on the both n-heptane/ZSM-5 and n-heptane/ZSM-11 systems showed also the defectiveness of the commensurate “freezing” interpretation.

Published
2007

5. Studies by In Situ and Real-Time Synchrotron Imaging of Interface Dynamics and Defect Formation in Solidification Processing

Author

Guillaume Reinhart, Holger Klein, Jürgen Härtwig, Bernard Billia, Thomas Schenk, Nathalie Mangelinck-Noël, J. Baruchel, Viviana Cristiglio, B. Grushko, J. Gastaldi, Henri Nguyen-Thi, Laboratoire matériaux et microélectronique de Provence (L2MP), Université Paul Cézanne - Aix-Marseille 3-Université de Provence - Aix-Marseille 1-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), European Synchrotron Radiation Facility (ESRF), IFF Forschungszentrum Jülich (IFF), Forschungszentrum Jülich GmbH | Centre de recherche de Juliers, Helmholtz-Gemeinschaft = Helmholtz Association-Helmholtz-Gemeinschaft = Helmholtz Association, Laboratoire de Cristallographie, Centre National de la Recherche Scientifique (CNRS), Laboratoire matériaux et microélectronique de Provence ( L2MP ), Université Paul Cézanne - Aix-Marseille 3-Université de Provence - Aix-Marseille 1-Université de Toulon ( UTLN ) -Centre National de la Recherche Scientifique ( CNRS ), Centre de recherche de la matière condensée et des nanosciences ( CRMCN ), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique ( CNRS ), European Synchrotron Radiation Facility ( ESRF ), IFF Forschungszentrum Jülich ( IFF ), Forschungszentrum Jülich GmbH, and Centre National de la Recherche Scientifique ( CNRS )

Subjects
Materials science, Nucleation, Synchrotron radiation, Solidification dynamics, 02 engineering and technology, 01 natural sciences, Metallic alloys, law.invention, Synchrotron, law, 0103 physical sciences, Interface microstructure, Composite material, 010306 general physics, Supercooling, Directional solidification, X-ray imaging, Quasicrystal, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Microstructure, Crystallography, Beamline, [ CHIM.MATE ] Chemical Sciences/Material chemistry, 0210 nano-technology, Quasicrystals
Abstract

International audience; The solid microstructure built in the solid governs the properties of materials elaborated from the melt. In order to clarify the dynamical mechanisms controlling solidification processing, we use in situ and real-time synchrotron X-ray radiography at ESRF (European Synchrotron Radiation Facility) to analyze microstructure formation in thin aluminum alloys solidified in the Bridgman facility installed at the ID19 beamline. During directional solidification of Al - 3.5 wt% Ni alloys, global mechanical constraints induced by the shape are found to act on the solid microstructure. In particular, radiography videos of dendritic growth show disorientations of sidebranches induced by mechanical stresses. In the solidification of AlPdMn quasicrystals, live imaging reveals that facetted growth proceeds by the lateral motion of ledges at the solid-melt interface. When the solidification rate is increased, the kinetic undercooling becomes sufficient for grain nucleation and growth in the liquid. These grains develop specific features that can be attributed to grain competition and concomitant poisoning of growth caused by the rejection of aluminum in the melt.

Published
2006

6. In situ observation of pore evolution during melting and solidification of Al-Pd-Mn quasicrystals by synchrotron X-ray radiography

Author

Thomas Schenk, Nathalie Mangelinck-Noël, Jürgen Härtwig, J. Gastaldi, B. Grushko, H. Nguyen Thi, H. Klein, Bernard Billia, José Baruchel, P. Pino, G. Reinhart, Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), European Synchrotron Radiation Facility (ESRF), Laboratoire matériaux et microélectronique de Provence (L2MP), Université Paul Cézanne - Aix-Marseille 3-Université de Provence - Aix-Marseille 1-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Cristallographie, Centre National de la Recherche Scientifique (CNRS), IFF, FZ Juelich, Centre de recherche de la matière condensée et des nanosciences ( CRMCN ), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique ( CNRS ), ESRF, Laboratoire matériaux et microélectronique de Provence ( L2MP ), Université Paul Cézanne - Aix-Marseille 3-Université de Provence - Aix-Marseille 1-Université de Toulon ( UTLN ) -Centre National de la Recherche Scientifique ( CNRS ), and Centre National de la Recherche Scientifique ( CNRS )

Subjects
Thermal equilibrium, [PHYS]Physics [physics], Supersaturation, [ PHYS ] Physics [physics], Materials science, Nucleation, Synchrotron radiation, Quasicrystal, 02 engineering and technology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Synchrotron, law.invention, Crystallography, Chemical physics, law, Vacancy defect, 0103 physical sciences, Physical Sciences, 010306 general physics, 0210 nano-technology, Directional solidification
Abstract

International audience; Abstract It is now generally admitted that pores are intriguing special features of quasicrystals. Therefore, we have performed an “in situ” and real time observation of the pore evolution during directional solidification and melting cycles of an icosahedral Al-Pd-Mn bi-grained sample by synchrotron X-ray radiography. Rather surprisingly, no pore was observed to grow during the solidification stages. Nucleation and growth of pores were firstly seen during melting. These pores were subsequently shrinking either just being absorbed or during resumption of directional solidification. It is concluded that the vacancy origin of pores is certainly valid whereas the vacancy supersaturation needed thereby to explain their growth would be more probably related to the peculiar structure of quasicrystal than to the destruction of the thermal equilibrium.

Published
2006

7. In situ and real-time probing of quasicrystal solidification dynamics by synchrotron imaging

Author

Thomas Schenk, Nathalie Mangelinck-Noël, Viviana Cristiglio, Bernard Billia, José Baruchel, Jürgen Härtwig, H. Nguyen Thi, B. Grushko, J. Gastaldi, H. Klein, G. Reinhart, Cinam, Hal, Laboratoire matériaux et microélectronique de Provence ( L2MP ), Université Paul Cézanne - Aix-Marseille 3-Université de Provence - Aix-Marseille 1-Université de Toulon ( UTLN ) -Centre National de la Recherche Scientifique ( CNRS ), Centre de recherche de la matière condensée et des nanosciences ( CRMCN ), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique ( CNRS ), European Synchrotron Radiation Facility ( ESRF ), IFF Forschungszentrum Jülich ( IFF ), Forschungszentrum Jülich GmbH, Laboratoire de Cristallographie CNRS, Grenoble, Université de Lille, Sciences Humaines et Sociales, Laboratoire matériaux et microélectronique de Provence (L2MP), Université Paul Cézanne - Aix-Marseille 3-Université de Provence - Aix-Marseille 1-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), European Synchrotron Radiation Facility (ESRF), IFF Forschungszentrum Jülich (IFF), Forschungszentrum Jülich GmbH | Centre de recherche de Juliers, Helmholtz-Gemeinschaft = Helmholtz Association-Helmholtz-Gemeinschaft = Helmholtz Association, Laboratoire de Cristallographie, and Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Icosahedral symmetry, Kinetics, [ PHYS.COND.CM-MS ] Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Nucleation, chemistry.chemical_element, 02 engineering and technology, 01 natural sciences, law.invention, Recoil, law, Aluminium, 0103 physical sciences, Fluid dynamics, ddc:530, 010302 applied physics, 81.10.Aj, 61.44.Br, 68.55.a, 81.30.Fb, Quasicrystal, 021001 nanoscience & nanotechnology, Synchrotron, [PHYS.COND.CM-MS] Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], chemistry, Chemical physics, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], 0210 nano-technology
Abstract

Quasicrystal growth remains an unsolved problem in condensed matter. The dynamics of the process is studied by means of synchrotron live imaging all along the solidification of icosahedral AlPdMn quasicrystals. The lateral motion of ledges driving faceted growth at the solid-melt interface is conclusively shown. When the solidification rate is increased, nucleation and free growth of new faceted grains occur in the melt due to the significant interface recoil induced by slow attachment kinetics. The detailed analysis of the evolution of these grains reveals the crucial role of aluminum rejection, both in the poisoning of their growth and driving fluid flow.

Published
2006

8. In situ analysis of equiaxed growth of aluminium–nickel alloys by x-ray radiography at ESRF

Author

Thomas Schenk, Nathalie Mangelinck-Noël, J. Gastaldi, Jürgen Härtwig, M-D Dupouy, Bernard Billia, H. Nguyen-Thi, Viviana Cristiglio, G. Reinhart, José Baruchel, Laboratoire matériaux et microélectronique de Provence ( L2MP ), Université Paul Cézanne - Aix-Marseille 3-Université de Provence - Aix-Marseille 1-Université de Toulon ( UTLN ) -Centre National de la Recherche Scientifique ( CNRS ), European Synchrotron Radiation Facility ( ESRF ), Elaboration par procédés magnétiques ( EPM ), Centre National de la Recherche Scientifique ( CNRS ), Centre de recherche de la matière condensée et des nanosciences ( CRMCN ), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique ( CNRS ), Laboratoire matériaux et microélectronique de Provence (L2MP), Université Paul Cézanne - Aix-Marseille 3-Université de Provence - Aix-Marseille 1-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), European Synchrotron Radiation Facility (ESRF), Elaboration par procédés magnétiques (EPM), Centre National de la Recherche Scientifique (CNRS), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), and Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Equiaxed crystals, Materials science, Acoustics and Ultrasonics, chemistry.chemical_element, Synchrotron radiation, 02 engineering and technology, 01 natural sciences, law.invention, Aluminium, law, 0103 physical sciences, Directional solidification, 010302 applied physics, Metallurgy, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Synchrotron, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Characterization (materials science), Nickel, Beamline, chemistry, [ CHIM.MATE ] Chemical Sciences/Material chemistry, 0210 nano-technology
Abstract

International audience; We present results obtained at the ID19 beamline of the European Synchrotron Radiation Facility (ESRF) by synchrotron x-ray radiographyduring the solidification of Al–Ni alloys. We focus on columnar dendritic and equiaxed solidification, and the transition between the two regimes. Thecolumnar to equiaxed transition is a critical and still pending issue in metallurgy. By making use of the high potential of synchrotron experimental tools for in situ and real-time characterization of the solid–liquid interface during directional solidification, we were able to provide insight into key physical phenomena, in particular, sedimentation, interaction and arrangement of equiaxed grains.

Published
2005

9. Structure and Deformations of Pd−Ni Core−Shell Nanoparticles

Author

Sergio Sao-Joao, J.M. Penisson, Sylvie Bourgeois, Suzanne Giorgio, Claude Henry, Chapon C, Centre de recherche de la matière condensée et des nanosciences ( CRMCN ), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Recherche sur la Réactivité des Solides ( LRRS ), Université de Bourgogne ( UB ) -Centre National de la Recherche Scientifique ( CNRS ), ME ( ME ), Commissariat à l'Énergie Atomique et aux Énergies Alternatives (CEA) - Grenoble, Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Recherche sur la Réactivité des Solides (LRRS), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS), Service de Physique des Matériaux et Microstructures (SP2M - UMR 9002), Institut Nanosciences et Cryogénie (INAC), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])

Subjects
DECOMPOSITION, STRAIN, Materials science, [ SPI.MAT ] Engineering Sciences [physics]/Materials, Nanoparticle, 02 engineering and technology, 010402 general chemistry, OXIDATION, 01 natural sciences, law.invention, [SPI.MAT]Engineering Sciences [physics]/Materials, Condensed Matter::Materials Science, X-ray photoelectron spectroscopy, law, Microscopy, Materials Chemistry, LEIS, Physical and Theoretical Chemistry, High-resolution transmission electron microscopy, Spectroscopy, Bimetallic strip, 021001 nanoscience & nanotechnology, REACTIVITY, 0104 chemical sciences, Surfaces, Coatings and Films, INTERFACE, Crystallography, SURFACE CHARACTERIZATION, Chemical engineering, Transmission electron microscopy, GROWTH, METALS, Electron microscope, 0210 nano-technology, BIMETALLIC PARTICLES
Abstract

International audience; Homogeneous collections of Pd−Ni core−shell nanoparticles have been prepared by decomposition of metal−organic compounds and studied by several electron microscopy techniques: transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), high-resolution transmission electron microscopy (HRTEM), energy-filtered microscopy (EFTEM), and by X-ray photoelectron spectroscopy (XPS). The physical and chemical properties of the Pd shell are supposed to depend on its electronic properties, which are influenced by the presence of the Ni core and by the deformation in the Pd lattice. Here, the interfacial structure of Pd/Ni and the lattice deformations in the core and the shell are studied in detail. The catalytic properties of the pure metal and the bimetallic particles, toward CO oxidation, have been investigated.

Published
2005

10. Templated dewetting of single-crystal sub-millimeter-long nanowires and on-chip silicon circuits

Author

Meher Naffouti, Antonio M. Mio, Monica Bollani, Mario Lodari, Jean-Benoît Claude, Marco Salvalaglio, Marco Abbarchi, Ibtissem Fraj, Antoine Ronda, David Grosso, Mohammed Bouabdellaoui, Isabelle Berbezier, Luc Favre, Stefano Di Corato, A. Benali, Axel Voigt, Alexey V. Fedorov, Giuseppe Nicotra, Institute of Photonics and Nanotechnologies (CNR-IFN), ICT Institute of Politecnico di Milano, Institute of Scientific Computing, Department of Mathematics, Technische Universität Dresden = Dresden University of Technology (TU Dresden), Laboratory of Physics of Condensed Matter and Renewable Energy, Faculty of Sciences and Technology, Hassan II University of Casablanca, Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), CNR Istituto di Fotonica e Nanotecnologie [Padova] (IFN), Consiglio Nazionale delle Ricerche [Roma] (CNR), Department of Geology & Geophysics, Yale University [New Haven], Laboratoire de Micro-optoélectronique et Nanostructures [Monastir], Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), Laboratoire Pierre Aigrain (LPA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Electron mobility, Materials science, Silicon, Science, Nanowire, General Physics and Astronomy, chemistry.chemical_element, 02 engineering and technology, Hardware_PERFORMANCEANDRELIABILITY, 010402 general chemistry, 01 natural sciences, Article, General Biochemistry, Genetics and Molecular Biology, Si nanowires, law.invention, Monocrystalline silicon, law, Electronic devices, Hardware_INTEGRATEDCIRCUITS, Dewetting, lcsh:Science, Electronic circuit, Si dewetting, Multidisciplinary, Nanowires, business.industry, Transistor, General Chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, chemistry, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Optoelectronics, lcsh:Q, phase field simulation, Photonics, 0210 nano-technology, business, Hardware_LOGICDESIGN
Abstract

Large-scale, defect-free, micro- and nano-circuits with controlled inter-connections represent the nexus between electronic and photonic components. However, their fabrication over large scales often requires demanding procedures that are hardly scalable. Here we synthesize arrays of parallel ultra-long (up to 0.75 mm), monocrystalline, silicon-based nano-wires and complex, connected circuits exploiting low-resolution etching and annealing of thin silicon films on insulator. Phase field simulations reveal that crystal faceting and stabilization of the wires against breaking is due to surface energy anisotropy. Wires splitting, inter-connections and direction are independently managed by engineering the dewetting fronts and exploiting the spontaneous formation of kinks. Finally, we fabricate field-effect transistors with state-of-the-art trans-conductance and electron mobility. Beyond the first experimental evidence of controlled dewetting of patches featuring a record aspect ratio of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sim$$\end{document}~1/60000 and self-assembled \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sim$$\end{document}~mm long nano-wires, our method constitutes a distinct and promising approach for the deterministic implementation of atomically-smooth, mono-crystalline electronic and photonic circuits., Fabricating defect-free micro- and nano-circuits over large scales with controlled interconnections remains a challenge. Here, Bollani et al. show a dewetting strategy for engineering arrays of parallel Si-based nanowires up to 0.75 mm and complex interconnected circuits of monocrystalline Si on a chip.

Published
2019

11. Structure of a Zn monolayer on Ag(111) and Ag(110) substrates: an AES, LEED and STM study

Author

B. Ealet, Haik Jamgotchian, Carole Fauquet, Sébastien Vizzini, H. Maradj, M. Ghamnia, J. P. Biberian, Nabil Rochdi, Bernard Aufray, Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), and Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)

Subjects
Materials science, Ag(110), Substrate surface, STM, FOS: Physical sciences, 02 engineering and technology, Substrate (electronics), 010402 general chemistry, 01 natural sciences, law.invention, Moiré pattern, law, Monolayer, Materials Chemistry, Auger electron spectroscopy, Condensed Matter - Materials Science, Low-energy electron diffraction, Ag(111), Materials Science (cond-mat.mtrl-sci), Surfaces and Interfaces, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, Surfaces, Coatings and Films, Crystallography, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Scanning tunneling microscope, superstructure, 0210 nano-technology, Layer (electronics), Superstructure (condensed matter), Zn monolayer
Abstract

Auger Electron Spectroscopy, Low Energy Electron Diffraction and Scanning Tunneling Microscopy have been used to study the atomic structure of a Zn monolayer deposited on Ag(111) and Ag(110) substrates at room temperature. On both faces, there is formation of a close packed monolayer of Zn covering the entire substrate surface and giving rise to specific Moir{\'e} patterns. From a comprehensive LEED and STM data analysis, we deduce that the Zn monolayer adopts a (111) structure equivalent to a pure Zn layer rotated with respect to the silver substrate, of about $1.5^\circ$ on the Ag(111) face and of about $4.5^\circ$ on the Ag(110) face giving rise respectively to ($\sqrt{156}\times\sqrt{156})R18^\circ$ and c(12x6) superstructures.

Published
2019

12. Tuning bimetallic catalysts for a selective growth of SWCNTs

Author

Salomé Forel, Annick Loiseau, Hakim Amara, Laure Catala, Christophe Bichara, Alice Castan, Vincent Huc, Ileana Florea, Costel Sorin Cojocaru, Talal Mallah, Frédéric Fossard, Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), Laboratoire d'étude des microstructures [Châtillon] (LEM - ONERA - CNRS), Université Paris Saclay (COmUE)-ONERA-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique du solide (Namur) (LPS), Facultés Universitaires Notre Dame de la Paix (FUNDP) - Namur, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace, Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Université de Strasbourg (UNISTRA), Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), Service de Chimie Moléculaire (SCM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), LEM, UMR 104 CNRS-ONERA, Université Paris Saclay (COmUE) [Châtillon], ONERA-Centre National de la Recherche Scientifique (CNRS)-Université Paris Saclay (COmUE), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), ANR-13-BS10-0015,SYNAPSE,Synthèse de Nanotubes à Propriétés Spécifiques(2013), ANR-10-EQPX-0050,TEMPOS,Microscopie electronique en transmission sur le plateau Palaiseau Orsay Saclay(2010), European Project: 604472,EC:FP7:NMP,FP7-NMP-2013-EU-Japan,IRENA(2013), Université Paris-Sud - Paris 11 (UP11)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Coalescence (physics), Materials science, Condensed Matter - Mesoscale and Nanoscale Physics, chemistry.chemical_element, Nanoparticle, FOS: Physical sciences, 02 engineering and technology, Applied Physics (physics.app-ph), Physics - Applied Physics, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Ruthenium, Catalysis, chemistry, Chemical engineering, Phenomenological model, Mesoscale and Nanoscale Physics (cond-mat.mes-hall), [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], General Materials Science, Solubility, 0210 nano-technology, Carbon, Bimetallic strip
Abstract

Recent advances in structural control during the synthesis of SWCNTs have in common the use of bimetallic nanoparticles as catalysts, despite the fact that their exact role is not fully understood. We therefore analyze the effect of the catalyst' s chemical composition on the structure of the resulting SWCNTs by comparing three bimetallic catalysts (FeRu, CoRu and NiRu). A specific synthesis protocol is designed to impede the catalyst nanoparticle coalescence mechanisms and stabilize their diameter distributions throughout the growth. Owing to the ruthenium component which has a limited carbon solubility, tubes grow in tangential mode and their diameter is close to that of their seeding nanoparticle. By using as-synthesized SWCNTs as a channel material in field effect transistors, we show how the chemical composition of the catalysts and temperature can be used as parameters to tune the diameter distribution and semiconducting-to-metallic ratio of SWCNT samples. Finally, a phenomenological model, based on the dependence of the carbon solubility as a function of catalyst nanoparticle size and nature of the alloying elements, is proposed to interpret the results., 10 pages, 6 figures

Published
2018

13. Hydrothermal Steel Slag Valorization—Part II: Hydrogen and Nano-Magnetite Production

Author

Camille Crouzet, Fabrice Brunet, Nadir Recham, Anne-Line Auzende, Nathaniel Findling, Valérie Magnin, Jean-Henry Ferrasse, Bruno Goffé, Institut des Sciences de la Terre (ISTerre), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-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]), Laboratoire de géologie de l'ENS (LGENS), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Laboratoire réactivité et chimie des solides - UMR CNRS 7314 (LRCS), Université de Picardie Jules Verne (UPJV)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Mécanique, Modélisation et Procédés Propres (M2P2), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), ANR-10-LABX-0056,OSUG@2020,Innovative strategies for observing and modelling natural systems(2010), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université de Picardie Jules Verne (UPJV)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, magnetite, Hydrogen, hydrogen production, Geochemistry, chemistry.chemical_element, 02 engineering and technology, Activation energy, 010402 general chemistry, 01 natural sciences, 7. Clean energy, Hydrothermal circulation, Ferrous, chemistry.chemical_compound, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, lcsh:Science, Dissolution, Magnetite, Hydrogen production, Slag, 021001 nanoscience & nanotechnology, BOF steel slag, 0104 chemical sciences, chemistry, Chemical engineering, visual_art, visual_art.visual_art_medium, General Earth and Planetary Sciences, hydrothermal oxidation, lcsh:Q, nanoparticles, 0210 nano-technology
Abstract

International audience; The effect of acidic conditions (in a pH range of 3 to 6) and temperature on the kinetics of the hydrothermal oxidation of ferrous iron contained in BOF steel slag has been tested in the 150–350 • C range for acid acetic concentrations from 0 to 4 M. Reaction progress was monitored with the amount of produced H 2. Higher temperature and lower pH are found to enhance the hydrothermal oxidation kinetics of the slag. These two parameters are believed to increase iron dissolution rate which has already been identified as the rate limiting step of the hydrothermal oxidation of pure FeO. An activation energy of 28 ± 4 kJ/mole is found for the hydrothermal oxidation of the steel slag which compares very well with that of pure FeO under similar conditions. In the case of the slag run in water at 300 • C for 70.5 h, magnetite product has been separated magnetically and characterized. Particles were found to fall in three size ranges: 10–30 nm, 100–300 nm, and 1–10 µm. The smallest fraction (10–30 nm) is comparable to the 10–20 nm size range that is achieved when nanomagnetite are synthesized by co-precipitation methods. Obviously, the production of nanomagnetite enhances the economic interest of the hydrothermal processing of steel slags, which has already proven its capacity to produce high-purity H 2 .

Published
2017

14. Crystal-chemistry control of the mechanical properties of 2:1 clay minerals

Author

Olivier Grauby, Alain Baronnet, Franz-Josef Ulm, Jérémie Berthonneau, Christian G. Hoover, Roland J.-M. Pellenq, Centre Interdisciplinaire de Conservation et Restauration du Patrimoine (CICRP), Ministère de la Culture et de la Communication (MCC), Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), Massachusetts Institute of Technology (MIT), Multiscale Material Science for Energy and Environment (MSE 2), and Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Chemistry, Muscovite, Mineralogy, 020101 civil engineering, Geology, 02 engineering and technology, Nanoindentation, engineering.material, 021001 nanoscience & nanotechnology, 0201 civil engineering, Brittleness, Geochemistry and Petrology, visual_art, engineering, visual_art.visual_art_medium, Phlogopite, Clay mineral X-ray diffraction, Clintonite, 0210 nano-technology, Clay minerals, ComputingMilieux_MISCELLANEOUS, Pyrophyllite, [SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy
Abstract

Clay minerals are the main constituents of the clay matrix of a wide variety of sedimentary deposits. When subjected to burial, some of these minerals undergo phase transitions accompanied by atomic substitutions which ultimately impact the cohesive interactions between their constitutive layers. The most common among such transitions is smectite illitization, which is also highly relevant for oil and gas exploration and production from source rocks. The impact of this transition on the mechanical properties of clay minerals as well as clay bearing rocks remains, however, to be properly addressed. To this end, a set of macroscopic single 2:1 clay minerals (pyrophyllite, talc, vermiculite, phlogopite, muscovite, and clintonite) representative of the two octahedral fillings and the variation in surface charge densities was investigated. A hybrid experimental-modeling approach is proposed, which combines nanoindentation in orthogonal directions (x1 and x3-directions) with analytical derivations of the cohesive energy (Ui) using XRD and TEM-EDS measurements. The results highlight that the interlayer energy defines the elasticity (modulus M), strength (hardness H) and ductility behavior (M/H) of these materials; and not the bond energy stored into the constituent layers. This finding permits the derivation of predictive stiffness and strength functional relations as derivatives of the interlayer energy that account for the arrangement of nanoscale layers and the interlayer composition. These relations suggest that as the cohesion increases with the coulombic interactions through progressive smectite illitization, the system loses its capacity to dissipate applied energy by dislocation mechanisms in between the layers, entailing an increase in brittleness of the clay particles with burial. By way of conclusion, the geophysics and geochemistry implications of these results for predicting the macroscopic mechanical performance of clay bearing geomaterials, such as economically valuable source rocks, are discussed.

Published
2017

15. Structural and physical–chemical behavior of a CeO2 nanoparticle based diesel additive during combustion and environmental release

Author

Catherine Mouneyrac, Wei Liu, Marie Tella, Mélanie Auffan, Bernard Angeletti, A Pariat, Martiane Cabié, Daniel Borschneck, Laure Giamberini, G. Landrot, Jérôme Rose, Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Central China Normal University [Wuhan, China], Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement, Institut National de la Recherche Agronomique (INRA)-Institut de Recherche pour le Développement (IRD [France-Ouest])-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), Department of Plant and Soil Sciences, University of Delaware [Newark], Ecole Supérieure des Sciences Commerciales d'Angers (ESSCA), Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Terre et Environnement de Lorraine (OTELo), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS), European Commission, OSU-Institut Pytheas, ANR-10-LABX-0021,RESSOURCES21,Strategic metal resources of the 21st century(2010), ANR-11-IDEX-0001,Amidex,INITIATIVE D'EXCELLENCE AIX MARSEILLE UNIVERSITE(2011), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Groupe ESSCA (ESSCA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Terre et Environnement de Lorraine (OTELo), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), and ANR-10-LABX-0021/10-LABX-0021,RESSOURCES21,Strategic metal resources of the 21st century(2010)

Subjects
Materials science, Materials Science (miscellaneous), Kinetics, Nanoparticle, Nanotechnology, 02 engineering and technology, 010501 environmental sciences, 021001 nanoscience & nanotechnology, Combustion, 01 natural sciences, 7. Clean energy, Diesel fuel, Colloid, Chemical engineering, [SDE]Environmental Sciences, Degradation (geology), Chemical stability, 0210 nano-technology, Dissolution, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, General Environmental Science
Abstract

International audience; The colloidal and chemical stability of CeO2 nanoparticles used in a diesel additive (viz. Envirox™) was studied at different stages of their lifecycle (formulation, use, end of life). After combustion at a temperature close to that of diesel engines, the size of the CeO2 crystallites increased significantly without detectable Ce(III) in the structure and remaining organic compounds at the surface. Regardless of the aging conditions (salinity, light, pH), the dissolution kinetics of the combusted particles were slowed down compared to that of the initial CeO2 nanoparticles. After 2 days at 0.1 g L−1 of salts, no more than 0.01% of the total Ce was released from the 850 °C-combusted Envirox™ versus 1.5% for the uncombusted Envirox™. Both the crystal growth during combustion and the degradation of the organic matrix will govern the aggregation and dissolution kinetics/mechanisms once the CeO2 particles are released into the environment at different stages of their lifecycle. Such a study is a prerequisite needed before any assessment of the environmental risks of CeO2 nanoparticle-based diesel additives is performed.

Published
2017

16. Raman characterization of synthetic magnesian calcites

Author

Angèle Ricolleau, Didier Laporte, Jonathan Perrin, George R. Rossman, Daniel Vielzeuf, Nicole Floquet, Institut des Sciences de la Terre (ISTerre), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-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]), Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Magmas et Volcans (LMV), Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), and Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Calcite, Magnesium, Dolomite, Analytical chemistry, chemistry.chemical_element, Mineralogy, 02 engineering and technology, 010502 geochemistry & geophysics, 021001 nanoscience & nanotechnology, 01 natural sciences, Amorphous calcium carbonate, Amorphous solid, chemistry.chemical_compound, symbols.namesake, Geophysics, chemistry, Geochemistry and Petrology, symbols, 0210 nano-technology, Raman spectroscopy, Spectroscopy, 0105 earth and related environmental sciences, Magnesite, [SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy
Abstract

International audience; Magnesian calcites are important components of sediments and biominerals. Although Raman spectra of calcite, dolomite, and magnesite are well known, those of magnesian calcites deserve further investigation. Nineteen syntheses of magnesian calcites covering the range 0-50 mol% MgCO3 have been carried out at high pressure and temperature (1-1.5 GPa, 1000-1100 degrees C). The crystalline run products have been characterized by m-Raman spectroscopy. For all lattice and internal modes (L, T, nu(1), nu(4), 2 nu(2)) but nu(3), wavenumbers align closer to the calcitedolomite line than the calcite-magnesite line. The compositional dependence is strong and regression curves with high correlation coefficients have been determined. Full-width at half maximum (FWHM) plot along parabolas that depart from the calcite-dolomite or calcite-magnesite lines. The limited data dispersion of both shifts and FWHM allow using Raman spectral properties of magnesian calcites to determine the Mg content of abiotic calcites. A comparison with Raman data from the literature obtained on synthetic magnesian amorphous calcium carbonate (Mg ACC) shows that the wavenumber position of the ACC n1 mode is systematically shifted toward lower values, and that their FWHM are higher than those of their crystalline counterparts. The FWHM parameters of crystalline and amorphous materials do not overlap, which allows a clear-cut distinction between crystalline and amorphous materials. In synthetic magnesian calcites, the shift and FWHM of Raman bands as a function of magnesium can be interpreted in terms of changes of metal-O bond lengths resulting from the replacement of calcium by magnesium. The facts that the wavenumber of magnesian calcites are close to the calcite-dolomite line (not calcite-magnesite), that the FWHM of the T, L, and nu(4) modes reach a maximum around 30 +/- 5 mol% MgCO3, and that a peak specific to dolomite at 880 cm(-1) is observed in high-magnesian calcites indicate that dolomite-like ordering is present above similar to 10 mol% MgCO3. Mg atom clustering in cation layers combined with ordering in successive cation basal layers may account for the progressive ordering observed in synthetic magnesian calcites.

Published
2016

17. Electric field induced motion of metallic droplets: Application to submicron contactor

Author

Frédéric Bedu, P. Sudraud, Dominique Chatain, M. Prestigiacomo, H. Dallaporta, D. Tonneau, Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), Orsay Physics (ZAC Saint Charles), and Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)

Subjects
Materials science, Ion beam, Scanning electron microscope, chemistry.chemical_element, Nanotechnology, 02 engineering and technology, 01 natural sciences, Focused ion beam, 0103 physical sciences, Materials Chemistry, Electrical measurements, Electrical and Electronic Engineering, Gallium, Instrumentation, Electrical conductor, 010302 applied physics, business.industry, Process Chemistry and Technology, 021001 nanoscience & nanotechnology, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, chemistry, Electrode, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Optoelectronics, 0210 nano-technology, business, Current density
Abstract

This article reports the monitoring of reversible displacement of a gallium droplet on a tungsten submicron wire deposited by focused ion beam from tungsten hexacarbonyl precursor. The authors demonstrate that by applying a voltage to the wire terminals, the internal electric field created along the wire produces the motion of the droplet. Since the matter involved in this displacement is conductive, the authors show that it is possible to build a submicron electrical switch. Contact can be switched on and off between two electrodes separated by a submicron gap, by electrical monitoring the position of the conductive droplet. In nanoscience, connections of nano-objects are needed to demonstrate the peculiar electrical properties of such objects. A lot of studies have been devoted to direct writing of high quality metallic wires by local decomposition of gaseous molecules induced by tightly focused ion or electron beams. 1–4 These techniques are particularly suitable to link the micron world optical lithography to the nanoworld. Cross beam systems coupling a focused ion beam FIB and a scanning electron microscope SEM equipped with a gas injection system have been widely used in microelectronic industry for integrated circuit rewiring at the submicron scale. The deposited materials are often contaminated by C and O coming from the decomposition of the ligands of the precursor molecules, usually organometallic or metal organic molecules. Furthermore, extra contamination of the deposited wires occurs by implantation of gallium atoms coming from the Ga + ion beam itself. Consequently, the metal wire resistivity is usually up to 100 times higher than the bulk one. Tungsten nanowires 200 nm wide by 80 nm thick have been fabricated by a focused ion beam induced deposition process 5,6 FIBID from the dissociation of WC0 6 molecules and studied in our cross beam system equipped with in situ electrical measurements. A current density above a threshold value 5,6 of 1.4 10 7 A / cm 2 induces a wire annealing by Joule effect which improves their electrical conductivity. The high current density induces the exudation of gallium out of the wire and its merging as several droplets Fig. 1. The exudation of gallium is closely related to the light 3% decrease of the wire resistance between 1.1 and 4 V Fig. 1. Droplet formation along the wire takes place when the voltage reaches about 2.5 V. This value increases with the initial value of the resistance of the wire to get the current density threshold required. Increasing the voltage up to 4 V drives all the droplets toward the lowest potential electrode, leading to the formation of a unique droplet of about 550 nm in diameter SEM image inserted in Fig. 1. For a voltage above 4 V, the resistance of the wire drops due to the nonreversible crys-tallization of the tungsten wire. 5,6 The value of the resistance after the first ramping can be ten times less than the value of the resistance of the as-deposited wire. The droplet contains about 90 at. % of gallium atoms and 10 at. % of oxygen atoms as observed by ex situ energy dispersive x-ray analysis. Most of the oxygen contained in the droplet is a consequence of the sample transfer through air from one SEM to the other. A gallium droplet, which has been formed at one extremity of a wire, as explained previously, 5,6 migrates toward the opposite terminal if the voltage is reversed. The droplet is always driven toward the lowest potential electrode when the voltage applied 2.5 V induces a current density of about 1.4 10 7 A / cm 2 through the tungsten wire. Droplet position change was followed in situ by SEM. Figure 2 displays three images grabbed from a SEM video, separated in time by 0.6 s between Figs. 2a and 2b and 0.4 s between Figs. 2b and 2c. We started with one drop-let nearby the left electrode and slowly increased the voltage. One can see that the left droplet diameter decreases slightly while the right one increases. It demonstrates that the gal-lium transfer occurs from the left electrode to the right one by changing the polarity of the voltage between the two electrodes. During the transfer, the W wire remains unchanged between the initial and final states. It should be stressed that instead of moving at once from one point of the wire to the other, the droplet diameter decreases while simultaneously a Electronic

Published
2010

18. Intrusion and Retraction of Fluids in Nanopores: Effect of Morphological Heterogeneity

Author

Roland J.-M. Pellenq, Benoit Coasne, Anne Galarneau, Francesco Di Renzo, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), and Cinam, Hal

Subjects
Pore size, Work (thermodynamics), Chemistry, Nanotechnology, Molecular simulation, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, Porosimetry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Nanopore, Intrusion, General Energy, Phase (matter), [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Physical and Theoretical Chemistry, Composite material, 0210 nano-technology, Porous medium
Abstract

International audience; This paper reports on a molecular simulation study of intrusion and retraction of a non wetting fluid in silica nanopores without or with morphological defects (constrictions or undulations) to mimic mercury porosimetry in porous materials. All the pores considered in this work are of a finite length and are connected to bulk reservoirs so that they mimic real materials for which the confined fluid is always in contact with the external phase. Our results for pores with constant or variable cross-section are in qualitative agreement with experimental data: (1) the intrusion and retraction pressures are larger than the bulk saturating vapor pressures, (2) the intrusion and retraction pressures are decreasing functions of the pore size, and (3) entrapment of the confined fluid leads to irreversible intrusion/retraction isotherms (except for the smallest pore for which intrusion is reversible). Our data show that the intrusion pressure varies linearly with the pore diameter when both quantities are plotted in a logarithmic scale; the slope, -1.1 +/- 0.1, is close to the theoretical value -1 given by the Washburn – Laplace equation (the contact angle Θa is found about 102° +/- 15°). In contrast, the retraction pressure varies with a larger slope -1.6+/- 0.1, due to the fact that retraction consists of the nucleation of a gas bubble within the pore. We find that the intrusion chemical potential for the large cavities of the constricted pores corresponds to that for a regular cylindrical nanopore having the same diameter than the constriction, i.e. intrusion in the constricted pores occurs when the non wetting fluid invades the constrictions that isolate the large cavity from the bulk external phase. On the other hand, the retraction chemical potentials for pores with uneven diameter underestimates the value found for a regular cylindrical pore having the pore diameter of the wider parts of the variable-diameter pore. These results suggest that intrusion and retraction experiments (porosimetry) can be used to assess and characterize morphological defects in nanopores, provided that the pore size is known from other independent measurements. The present work also provides a theoretical frame to explain some discrepancies observed between properties assessed by mercury porosimetry and nitrogen adsorption.

Published
2009

19. Structural properties of GaAs surfaces nitrided in hydrazine-sulfide solutions

Author

L. Masson, V. P. Ulin, V. L. Berkovits, I. V. Makarenko, Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), and Cinam, Hal

Subjects
General Physics and Astronomy, Mineralogy, Gallium nitride, Nitride monolayer, 02 engineering and technology, Nitride, 01 natural sciences, Microetching, law.invention, chemistry.chemical_compound, Gallium arsenide, law, 0103 physical sciences, Monolayer, Scanning tunneling microscopy, 010302 applied physics, Auger electron spectroscopy, Surfaces and Interfaces, General Chemistry, Chemical nitridation, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Surfaces, Coatings and Films, Solutions, chemistry, Chemical engineering, Scanning tunneling microscope, Surface morphology, 0210 nano-technology, Vicinal, biotechnology, Hillock
Abstract

The surface structure of GaAs(1 0 0), (1 1 1)A, and (1 1 1)B substrates nitrided through the wet chemical treatment in hydrazine-sulfide solution have been studied by scanning tunneling microscopy (STM) under annealing in UHV. Such treatment has earlier been shown to produce a monolayer of gallium nitride on the (1 0 0)GaAs surface. The as-nitrided substrates of all surface orientations were found to be covered by an overfilm, which contains thioarsenic compounds and has a smooth relief. Thermal desorption of the overlfilm at about 530 °C opens the own relief of the nitrided surfaces. For the (1 0 0) orientation such relief is not microscopically planar and consists of nano-scale vicinal hillocks. These hillocks occur due to surface microetching which proceeds simultaneously with the formation of the surface nitride layer. We have shown that the wet nitridation procedure forms a monolayer of surface nitride on the (1 1 1)B surface. During nitridation the (1 1 1)B surface, as well as the (1 0 0) one, is affected by the microetching in the hydrazine-sulfide solution. Therefore, it exhibits a characteristic relief formed by triangular vicinal pyramids. At the same time the nitride film is not formed on the (1 1 1)A surface, which is more chemically inert, and where the surface etching is almost absent.

Published
2008

20. Anisotropy of Wetting

Author

Dominique Chatain, Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), and Cinam, Hal

Subjects
010302 applied physics, Surface (mathematics), Liquid metal, Materials science, Condensed matter physics, Young equation, Bonding in solids, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Condensed Matter::Soft Condensed Matter, Physics::Fluid Dynamics, Contact angle, Crystallography, Wetting transition, 0103 physical sciences, General Materials Science, Wetting, 0210 nano-technology, Anisotropy
Abstract

Wetting of single-crystal surfaces of metallic solids and oxides by liquid metals and alloys is anisotropic because of the anisotropy of the energies of solid surfaces and of their interfaces with liquids. To provide a basis for a discussion of wetting anisotropy, we review first the literature on surface and interfacial energies in metal-metal and metal-ceramic systems. We then summarize the relevant literature on the anisotropy of the energies of solid surfaces and of solid-liquid interfaces. These energies are then used in conjunction with the Young equation to estimate the expected anisotropy of wetting. Some serious discrepancies are found between these estimates and the experimental anisotropy of wetting. We show that under certain experimental conditions the wetting angles that have been determined are not Young contact angles.

Published
2008

21. Adsorption of Simple Fluid on Silica Surface and Nanopore: Effect of Surface Chemistry and Pore Shape

Author

Francesco Di Renzo, Roland J M Pellenq, Benoit Coasne, Anne Galarneau, Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Cinam, Hal, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), and Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Evaporation, Mineralogy, Binary compound, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, chemistry.chemical_compound, Adsorption, Electrochemistry, General Materials Science, Physics::Chemical Physics, ComputingMilieux_MISCELLANEOUS, Spectroscopy, Capillary condensation, Condensation, Substrate (chemistry), Surfaces and Interfaces, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, Nanopore, Chemical engineering, chemistry, Meniscus, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], 0210 nano-technology
Abstract

This paper reports a molecular simulation study on the adsorption of simple fluids (argon at 77 K) on hydroxylated silica surfaces and nanopores. The effect of surface chemistry is addressed by considering substrates with either partially or fully hydroxylated surfaces. We also investigate the effect of pore shape on adsorption and capillary condensation by comparing the results for cylindrical and hexagonal nanopores having equivalent sections (i.e., equal section areas). Due to the increase in the polarity of the surface with the density of OH groups, the adsorbed amounts for fully hydroxylated surfaces are found to be larger than those for partially hydroxylated surfaces. Both the adsorption isotherms for the cylindrical and hexagonal pores conform to the typical behavior observed in the experiments for adsorption/condensation in cylindrical nanopores MCM-41. Capillary condensation occurs through an irreversible discontinuous transition between the partially filled and the completely filled configurations, while evaporation occurs through the displacement at equilibrium of a hemispherical meniscus along the pore axis. Our data are also used to discuss the effect of surface chemistry and pore shape on the BET method. The BET surface for fully hydroxylated surfaces is much larger (by 10-20%) than the true geometrical surface. In contrast, the BET surface significantly underestimates the true surface when partially hydroxylated surfaces are considered. These results suggest that the surface chemistry and the choice of the system adsorbate/adsorbent is crucial in determining the surface area of solids using the BET method.

Published
2008

22. Dynamic observations of Au catalysts by environmental electron microscopy

Author

M. Cabié, Claude Henry, Suzanne Giorgio, Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), and Cinam, Hal

Subjects
Gold cluster, Chemistry, Ultra-high vacuum, Analytical chemistry, 02 engineering and technology, Substrate (electronics), 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Atomic units, 0104 chemical sciences, law.invention, Inorganic Chemistry, Materials Science(all), law, Energy filtered transmission electron microscopy, Deposition (phase transition), General Materials Science, Electron microscope, 0210 nano-technology, High-resolution transmission electron microscopy
Abstract

Au clusters in the size range (1–8 nm), supported on MgO and TiO2, are studied at the atomic scale by High Resolution Transmission Electron Microscopy (HRTEM), in standard conditions and during cycles of gas treatments by environmental HRTEM. Their morphology, the structure of the interface with the substrate and their adhesion energy are deduced from top and profile views, according to the preparation techniques, by atomic deposition in ultra high vacuum or by deposition precipitation in wet conditions.

Published
2008

23. Structural and optical properties of pulsed laser deposited V2O5 thin films

Author

Suzanne Giorgio, László Nánai, László Korösi, Szabolcs Beke, Wladimir Marine, Cinam, Hal, Centre de recherche de la matière condensée et des nanosciences (CRMCN), and Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS)

Subjects
010302 applied physics, Chemistry, Metals and Alloys, Analytical chemistry, 02 engineering and technology, Surfaces and Interfaces, 021001 nanoscience & nanotechnology, 01 natural sciences, Nanocrystalline material, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Pulsed laser deposition, Amorphous solid, Absorption edge, X-ray photoelectron spectroscopy, 0103 physical sciences, Tauc plot, Materials Chemistry, Thin film, 0210 nano-technology, High-resolution transmission electron microscopy
Abstract

Pulsed laser deposited nanocrystalline V 2 O 5 thin films were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM) and optical spectroscopy. The films were deposited on amorphous glass substrates, keeping the O 2 partial pressure at 13.33 Pa and the substrate temperature at 220 °C. The characteristics of the films were changed by varying the laser fluence and repetition rate. XRD revealed that films are nanocrystalline with an orthorhombic structure. XPS shows the sub-stoichiometry of the films, that generally relies on the fact that during the formation process of V 2 O 5 films, lower valence oxides are also created. From the HRTEM images, we observed the size evolution and distribution characteristics of the clusters in the function of the laser fluence. From the spectral transmittance we determined the absorption edge using the Tauc plot. Calculation of the Bohr radius for V 2 O 5 is also reported.

Published
2008

24. Decomposition of methanol by Pd, Co, and bimetallic Co–Pd catalysts: A combined study of well-defined systems under ambient and UHV conditions

Author

Holger Borchert, Suzanne Giorgio, Volkmar Zielasek, Marcus Bäumer, Tobias Nowitzki, Yu. Borchert, Birte Jürgens, Peter Behrend, Claude Henry, Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), and Cinam, Hal

Subjects
Chemistry, Inorganic chemistry, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, Heterogeneous catalysis, 7. Clean energy, 01 natural sciences, Decomposition, Catalysis, 0104 chemical sciences, chemistry.chemical_compound, Transition metal, 13. Climate action, Desorption, Dehydrogenation, Methanol, Physical and Theoretical Chemistry, 0210 nano-technology, Bimetallic strip
Abstract

We investigated the decomposition of methanol over Pd-based catalysts and the influence of Co as a second metal. To obtain mechanistic information on the reaction, we prepared structurally well-defined systems for studies in the ambient pressure regime and systems suitable for UHV studies in a dual approach. For the ambient pressure regime, monometallic and bimetallic Co/Pd nanoparticles supported on MgO were prepared by a wet-chemical method. FTIR spectroscopy was used to analyze the surface species that formed on the catalysts in the interaction with methanol, and the catalytic performance was studied in continuous-flow reactors. We found that methanol is dehydrogenated to CO already at room temperature by the Pd and Pd–Co catalysts, but high steady-state conversion requires temperatures above ∼150 °C. As could be shown by parallel studies of methanol decomposition on model catalysts prepared by physical vapor deposition under UHV conditions, CO desorption is the limiting factor at lower temperature. Pure Pd catalysts were found to be more active for methanol decomposition than the bimetallic Co–Pd catalysts. Although electronic effects in the bimetallic system facilitate desorption of CO at low temperature, this cannot compensate for the lower intrinsic activity of Co sites. We also investigated the influence of small amounts of oxygen on the decomposition of methanol. The activity of the Me/MgO catalysts was found to be higher in the presence of oxygen than in the absence of oxygen. Oxygen facilitates the removal of carbon species resulting from the C O bond scission reaction channel.

Published
2008

25. Effect of Morphological Defects on Gas Adsorption in Nanoporous Silicas

Author

Francesco Di Renzo, Benoit Coasne, Anne Galarneau, Roland J M Pellenq, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), and Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)

Subjects
Quantitative Biology::Biomolecules, Work (thermodynamics), Materials science, Chromatography, Capillary condensation, Nanoporous, Condensation, Evaporation, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Quantitative Biology::Subcellular Processes, Hysteresis, Nanopore, General Energy, Adsorption, Chemical engineering, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Physical and Theoretical Chemistry, 0210 nano-technology
Abstract

International audience; This paper reports a molecular simulation study on the adsorption of a simple fluid in nanoporous silicas with or without morphological defects (constrictions). All the pores considered in this work are of a finite length and are connected to a bulk reservoir so that they mimic real materials for which the confined fluid is always in contact with the external gas phase. The adsorption isotherms for the regular cylindrical pores conform to the typical experimental behavior for MCM-41 as the adsorbed amount increases continuously in the multilayer adsorption regime until a jump occurs due to capillary condensation of the fluid within the pore. The evaporation pressures are lower than the condensation pressures, so that hysteresis loops are observed. The condensation and evaporation mechanisms for the pores with constrictions depart significantly from what is observed for regular non-defective nanopores. Depending on the size, length, and number of constrictions in the pores, the filling and emptying processes are found to be of different nature. In every case, these mechanisms involve the coexistence between the confined liquid and some gas nanobubbles that are trapped within the main cavities of the pore. It is also found that the finite length of the pore introduces some heterogeneity in the adsorption and desorption processes; the filling and emptying of the regions (constriction and/or cavities) near the pore surface differs from those of the regions in the pore center. The desorption process can occur through different mechanisms such as cavitation, pore blocking effects with at equilibrium evaporation, or several combined pore blocking effects. Adsorption isotherms can be used to assess and characterize morphological defects in nanopores. In contrast, our results suggest that microcalorimetry experiments such as measurements of the isosteric heat of adsorption cannot be used to gain information regarding such defects as all the data for the regular and constricted pores fall on the same curve.

Published
2007

26. Real-time andin situsolidification of Al-based alloys investigated by synchrotron radiation: a unique experimental set-up combining radiography and topography techniques

Author

Jürgen Härtwig, Thomas Schenk, H. Jung, H. Nguyen-Thi, Bernard Billia, Nathalie Mangelinck-Noël, J. Gastaldi, A. Buffet, José Baruchel, G. Reinhart, European Synchrotron Radiation Facility (ESRF), Laboratoire matériaux et microélectronique de Provence (L2MP), Université Paul Cézanne - Aix-Marseille 3-Université de Provence - Aix-Marseille 1-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Ecole Nationale Supérieure des Mines de Nancy (ENSMN), Institut Mines-Télécom [Paris] (IMT)-Université de Lorraine (UL), Centre de recherche de la matière condensée et des nanosciences (CRMCN), and Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS)

Subjects
In situ, Materials science, Radiography, Mechanical Phenomena, Synchrotron radiation, 02 engineering and technology, 01 natural sciences, 010305 fluids & plasmas, Optics, 0103 physical sciences, Materials Chemistry, Solidification microstructure, Electrical and Electronic Engineering, 010306 general physics, ComputingMilieux_MISCELLANEOUS, Directional solidification, 010302 applied physics, business.industry, Direct observation, 07.85.Qe, 61.72.Ff, 62.20.–x, 81.10.Aj, [CHIM.MATE]Chemical Sciences/Material chemistry, Surfaces and Interfaces, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, 0210 nano-technology, business
Abstract

International audience; A unique experimental set-up combining X-ray radiography and topography has been recently developed at the ESRF. It allows direct observation of the solidification microstructure by these two complementary imaging techniques. This combined observation offers new possibilities, in particular for the investigation of strains, stresses and defect formation during directional solidification. In this paper we present in detail the experimental device and selected results obtained for two Al-based alloys: Al–3.5 wt% Ni and β-Al3Mg2. For the first time, we were able to characterize and quantify (by using topography) mechanical phenomena observed by radiography during the growth process.

Published
2007

27. Pb induced charge accumulation on InAs(111)B

Author

Mats Göthelid, Karolina Szamota-Leandersson, R. Bugoi, Ulf O. Karlsson, G. Le Lay, Cinam, Hal, Centre de recherche de la matière condensée et des nanosciences (CRMCN), and Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS)

Subjects
Chemistry, Analytical chemistry, 02 engineering and technology, Surfaces and Interfaces, Synchrotron radiation photoelectron spectroscopy, Electrostatic induction, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Surfaces, Coatings and Films, chemistry.chemical_compound, Adsorption, X-ray photoelectron spectroscopy, 0103 physical sciences, Materials Chemistry, Valence band, Indium arsenide, 010306 general physics, 0210 nano-technology, Spectroscopy, Deposition (law)
Abstract

The Pb/InAs(111)B interface has been studied by synchrotron radiation photoelectron spectroscopy (SR-PES) of valence band and ln4d, As3d and Pb5d core levels. Room temperature deposition of similar ...

Published
2007

28. Femtosecond laser synthesized nanohybrid materials for bioapplications

Author

Wladimir Marine, Cs.L. Sajti, Vladimir Khodorkovsky, Suzanne Giorgio, Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), and Cinam, Hal

Subjects
Materials science, Photoluminescence, General Physics and Astronomy, Nanotechnology, 02 engineering and technology, 010402 general chemistry, Photochemistry, 7. Clean energy, 01 natural sciences, Laser ablation synthesis in solution, Nanomaterials, law.invention, chemistry.chemical_compound, law, Rhodamine B, High-resolution transmission electron microscopy, Laser ablation, Surfaces and Interfaces, General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Laser, 3. Good health, 0104 chemical sciences, Surfaces, Coatings and Films, chemistry, Femtosecond, 0210 nano-technology
Abstract

Hybrid nanomaterials were synthesized by adopting femtosecond laser ablation of a ZnO target in pure ethanol. Dye molecules were grafted onto the ZnO nanoparticles by mixing colloidal ZnO–ethanol solution prepared by laser ablation to Tetramethylrhodamine B isothiocyante, or to Rhodamine B solutions. Strongly facetted nanohybrid particles were observed with an average size of 15 nm, by HRTEM measurements. From photoluminescence spectroscopy of the nanohybrids after single and multiphoton excitations, we observed energy transfer from the ZnO nanoparticles towards the attached dye molecules. Moreover, IR excitation spectra of the hybrid nanomaterials reveal the emission of the grafted dye via two photon absorption of the ZnO.

Published
2007

29. Controlled growth of aluminum oxide thin films on hydrogen terminated Si(001) surface

Author

Hamid Oughaddou, J.P. Bibérian, C. Coudreau, Vlado K. Lazarov, Bernard Aufray, Jean-Louis Lazzari, C. Leandri, B. Ealet, A. Kohn, Sébastien Vizzini, K. Nguyen, F. Arnaud d’Avitaya, Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), and Cinam, Hal

Subjects
inorganic chemicals, 010302 applied physics, Auger electron spectroscopy, Silicon, Electron energy loss spectroscopy, Oxide, Analytical chemistry, chemistry.chemical_element, Equivalent oxide thickness, 02 engineering and technology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Inorganic Chemistry, Atomic layer deposition, chemistry.chemical_compound, chemistry, 0103 physical sciences, Materials Chemistry, Thin film, 0210 nano-technology, Silicon oxide
Abstract

Auger electron spectroscopy, energy electron loss spectroscopy, atomic force microscopy and transmission electron microscopy were used to characterize ultra-thin aluminum oxide films grown on hydrogen-terminated Si(0 0 1)–H substrates via a specific atomic layer deposition and oxidation technique. Oxide thin films grown in such a way are highly stable with temperature at least up to 700 °C. Band gap was estimated to be 6.6±0.2 eV, independent of thickness. Formation of the oxide layer slightly increases the initial roughness of silicon surface. Furthermore, no silicon oxide was found at the aluminum oxide–silicon interface.

Published
2007

30. Mn–Ge nanocluster formation vs. diluted magnetic semiconductuor formation

Author

V. Le Thanh, Aurélie Spiesser, Lisa Michez, Omar Abbes, Christophe Girardeaux, Alain Portavoce, Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), and Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)

Subjects
010302 applied physics, Materials science, Fabrication, Condensed matter physics, Spintronics, Mechanical Engineering, Metals and Alloys, chemistry.chemical_element, Germanium, 02 engineering and technology, Manganese, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Nanoclusters, chemistry, Ferromagnetism, Mechanics of Materials, 0103 physical sciences, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Curie temperature, General Materials Science, Binary system, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS
Abstract

The possible fabrication of spintronic devices based on the Mn–Ge binary system supports extensive investigations on the magnetic properties of Mn–Ge structures. However, the global magnetic signal of a given sample is sometime complex due to the coexistence of several objects of unknown magnetic properties. We report the existence of ferromagnetic Mn–Ge nanoclusters (2–4 nm) containing only 4–6% Mn with a Curie temperature of ∼43.5 K, usually attributed to an 1.2% Mn-rich diluted magnetic semiconductuor.

Published
2015

31. Interface structure of Ni nanoparticles on MgO (100): A combined HRTEM and molecular dynamic study

Author

Christine Mottet, Sergio Sao-Joao, Claude Henry, Suzanne Giorgio, J. Goniakowski, Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), Institut des Nanosciences de Paris (INSP), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Molecular dynamic, HRTEM, Analytical chemistry, Nanoparticle, chemistry.chemical_element, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, Molecular dynamics, High resolution electron microscopy, Materials Chemistry, Cluster (physics), High-resolution transmission electron microscopy, Chemistry, Surfaces and Interfaces, Interface, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, Surfaces, Coatings and Films, Crystallography, Nickel, Transmission electron microscopy, 0210 nano-technology, Metal clusters
Abstract

International audience; Ni clusters with an average size of 4 nm, supported on MgO micro-cubes were studied by high resolution electron microscopy (HRTEM) and image simulations by the multislice technique. Regular defects were evidenced in the metal clusters at the interface. Molecular dynamic calculations of a 4 nm cluster indicates the same type of defects.

Published
2006

32. Modeling of the dissolution of a pharmaceutical compound

Author

Eric Garcia, Stéphane Veesler, Sébastien Gerard, Jean-Paul Klein, Christian Hoff, Denis Mangin, Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), and Cinam, Hal

Subjects
Aqueous solution, Discretization, Chemistry, Kinetics, Population balance equation, Mineralogy, Thermodynamics, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, 0104 chemical sciences, Inorganic Chemistry, Mass transfer, Particle-size distribution, Materials Chemistry, 0210 nano-technology, Anisotropy, Dissolution
Abstract

This paper analyses the phenomena encountered in the dissolution of a powder composed by drug crystals using the complementarity between the experimental and numerical approach. A macroscopic model based on the population balance equation was developed to describe dissolution experiments. The population balance equation was discretized and solved with the method of classes. The experiments were performed in a perfectly mixed vessel. Different initial masses of solid particles were introduced. The size distribution of the initial particles was measured by image analysis to take into account the particle anisotropy. For each experiment, the evolution of the concentration during the dissolution process was followed by conductimetry. The concentration measurements show an acceleration of the overall dissolution kinetics at the beginning of the dissolution process, although the undersaturation decreases. This particular behavior suggests that the aggregated powder is first disaggregated under the effect of stirring. The introduction of a fragmentation mechanism in our model has allowed a correct description of the concentration profiles. Intrinsic dissolution kinetics was found to be controlled by mass transfer.

Published
2006

33. Application of synchrotron X-ray imaging to the study of directional solidification of aluminium-based alloys

Author

Nathalie Mangelinck-Noël, B. Grushko, Thomas Schenk, Jürgen Härtwig, H. Nguyen Thi, H. Klein, J. Gastaldi, Bernard Billia, José Baruchel, G. Reinhart, Viviana Cristiglio, European Synchrotron Radiation Facility (ESRF), Laboratoire matériaux et microélectronique de Provence (L2MP), Université Paul Cézanne - Aix-Marseille 3-Université de Provence - Aix-Marseille 1-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), Università degli studi di Torino = University of Turin (UNITO), Laboratoire de Cristallographie, Centre National de la Recherche Scientifique (CNRS), IFF Forschungszentrum Jülich (IFF), Forschungszentrum Jülich GmbH | Centre de recherche de Juliers, Helmholtz-Gemeinschaft = Helmholtz Association-Helmholtz-Gemeinschaft = Helmholtz Association, and Università degli studi di Torino (UNITO)

Subjects
Equiaxed crystals, Directional solidification, Materials science, Synchrotron radiation, chemistry.chemical_element, 02 engineering and technology, 01 natural sciences, law.invention, Inorganic Chemistry, Columnar-equiaxed transition, law, Aluminium, 0103 physical sciences, Materials Chemistry, Quasicrystal growth, 010302 applied physics, Metallurgy, X-ray, Quasicrystal, Dendrites, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Microstructure, Synchrotron, chemistry, X-ray radiography, Morphological stability, 0210 nano-technology
Abstract

International audience; Third generation synchrotron X-ray sources like ESRF (European Synchrotron Radiation Facility) have enhanced the capabilities of in situ and real-time X-ray imaging so that it is possible to follow the solid–liquid interface dynamics on metallic alloys with improved spatial and time resolution. In this paper, we focus on the solidification patterns of Al based alloys, visualised by absorption and phase contrast radiography at ESRF. Two metallic systems were selected for this study: (i) Al–3.5 wt% Ni (with and without refiners) for the analysis of columnar growth and equiaxed growth, and the influence of the refiners on the columnar to equiaxed transition (CET), which is a key point in solidification processing, (ii) Al72.4Pd20.5Mn7.1 for the analysis of interface shape of growing quasicrystals (QCs). For both alloys, striking features were observed and a preliminary discussion is presented. Those results demonstrate the high potential of ESRF Synchrotron source for the characterisation of the dynamical formation of the solid microstructure in materials processing.

Published
2005

34. Laser treatment of a steel surface in ambient air

Author

Philippe Delaporte, Marc Sentis, C. Leborgne, Thierry Sauvage, Nadjib Semmar, Wladimir Marine, Antonio Pereira, Anne-Lise Thomann, A. Basillais, Pascal Andreazza, Alain Cros, Laboratoire Lasers, Plasmas et Procédés photoniques (LP3), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), Groupe de recherches sur l'énergétique des milieux ionisés (GREMI), Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Centre de Recherche sur la Matière Divisée (CRMD), Centre d'Études et de Recherches par Irradiation (CERI), Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), and Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Scanning electron microscope, Analytical chemistry, Oxide, 02 engineering and technology, Nitride, Heat treatment, 01 natural sciences, 7. Clean energy, Nitrides, chemistry.chemical_compound, X-ray photoelectron spectroscopy, Ferrite (iron), Oxidation, 0103 physical sciences, Materials Chemistry, 010302 applied physics, Austenite, Laser ablation, Chemistry, Metals and Alloys, Surfaces and Interfaces, 021001 nanoscience & nanotechnology, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Surface modification, 0210 nano-technology
Abstract

International audience; We study the steel surface modifications induced by irradiation of several lasers in air.The surface modifications are found to depend on the laser properties (Krf, 248 nm, 26 ns; XeCl, 308 nm, 25 ns; Nd:YAG, 1064 or 532 nm, 5 or 10 ns).The treated surface features (morphology, chemical composition and crystalline structure) are analysed by complementary techniques, such as X-ray photoelectron spectroscopy, nuclear reactions, scanning electron microscopy and grazing incidence X-ray diffraction.First of all, it is shown that the carbon coming from the machining oils is successfully removed under all the studied conditions.The incorporation of oxygen and nitrogen (beyond 1 mm in depth) to the surface is also shown.In addition to the original ferrite phase, new crystalline compounds are detected after treatment such as austenite, oxides (FeO or Fe2O3, Fe3O4) and nitride (εFe2-3 N).Depending on the laser characteristics, the main formed crystalline phases are different (oxide or nitride).A discussion of the expected surface modification mechanisms is presented. Under some experimental conditions, the formation of a backdeposition layer composed of oxides and hydroxides is observed

Published
2004

35. Hole trapping in self-assembled SiGe quantum nanostructures

Author

Matthew P. Halsall, Isabelle Berbezier, I. D. Hawkins, A. Ronda, Anthony R. Peaker, Alain Portavoce, P.B. Kenway, F. Volpi, Science et Ingénierie des Matériaux et Procédés (SIMaP), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National Polytechnique de Grenoble (INPG)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Chimie du CNRS (INC)-Institut National Polytechnique de Grenoble (INPG), and Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)

Subjects
Photoluminescence, Materials science, Deep-level transient spectroscopy, Silicon, chemistry.chemical_element, Germanium, 02 engineering and technology, Substrate (electronics), 01 natural sciences, 0103 physical sciences, General Materials Science, 010306 general physics, ComputingMilieux_MISCELLANEOUS, Wetting layer, business.industry, Mechanical Engineering, Strained silicon, 021001 nanoscience & nanotechnology, Condensed Matter Physics, chemistry, Mechanics of Materials, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Optoelectronics, Light emission, 0210 nano-technology, business
Abstract

The electronic behaviour of boron-doped single germanium layers grown in a silicon matrix by solid source MBE has been studied by deep level transient spectroscopy (DLTS) and photoluminescence (PL). The structures result from the Si-capping of nine monolayers of germanium on (100) silicon at different substrate temperatures (650, 550 and 450 °C). Due to the growth procedure, the buried germanium structures consist of a wetting layer (WL) (typical of the Stranski–Krastanov growth mode of germanium in silicon) plus the self-assembled structure under the silicon cap. The detailed morphology of the structure depends on the growth temperature. Emission and trapping behaviours of the layer have been studied by DLTS and PL measurements, while Transmission Electron Microscope (TEM) observations were used to characterise the actual film morphology. We first show that the major electrical signal arising from the structure comes from the WL. The corresponding ground state depth clearly follows the trend imposed by a typical quantum confinement: the thinner the well, the higher the level. We also show that the electrical signal is maintained in the low-temperature-grown sample even if light emission from the WL is non-existent. The growth procedure coupled with PL results also allowed us to confirm the high level of elastic relaxation inherent to dome islands nucleation. The hole trapping behaviour of the WLs have also been investigated. A surprising point-defect-like behaviour is observed, suggesting that the WL capture rate is charge state independent.

Published
2003

36. Characterisation of a steel surface after XeCl laser irradiation

Author

Marc Sentis, Wladimir Marine, Ph. Delaporte, Antonio Pereira, Alain Cros, Laboratoire Lasers, Plasmas et Procédés photoniques (LP3), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)

Subjects
iron oxide, Materials science, Scanning electron microscope, Oxide, Analytical chemistry, General Physics and Astronomy, 02 engineering and technology, 01 natural sciences, Electron spectroscopy, law.invention, chemistry.chemical_compound, law, 0103 physical sciences, 010302 applied physics, Coalescence (physics), Auger electron spectroscopy, Surfaces and Interfaces, General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Laser, Surfaces, Coatings and Films, chemistry, laser surface treatment, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Surface modification, 0210 nano-technology, Layer (electronics)
Abstract

International audience; This study focuses on the surface modification of a low alloy steel by XeCl laser under ambient conditions. These modifications were investigated employing two complementary methods. Auger electron spectroscopy was employed for chemical characterisation and depth profile and Scanning electron microscopy for the surface morphology after laser irradiation. It is shown that laser treatment induce the formation of Fe(III) oxide, mainly Fe2O3. This oxide can be described as a multilayer structure. One part, e.g. the upper layer, is formed with Fe2O3 aggregates due to the coalescence of small particles of Fe2O3 formed in the plasma by reaction of matter ejected from the surface with O2 gas in the atmosphere. Under this layer deposited on the surface, we find a Fe2O3 structured layer corresponding to the oxidation of the melt layer.

Published
2003

37. Investigation of aprotinin (BPTI) solutions during nucleation

Author

Françoise Bonneté, Monika Budayova-Spano, Stéphane Veesler, Jean-Pierre Astier, Laboratoire de minéralogie, cristallographie de Paris (LMCP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), Centre de la Recherche sur les Mécanismes de la Croissance Cristalline (CRMC2), Université de la Méditerranée - Aix-Marseille 2-Centre National de la Recherche Scientifique (CNRS), and Université Pierre et Marie Curie - Paris 6 (UPMC)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Kinetics, Nucleation, Crystal growth, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Growth from solutions, Inorganic Chemistry, Crystal, chemistry.chemical_compound, Biocrystallization, Materials Chemistry, Biological macromolecules, Chemistry, Scattering, Small-angle X-ray scattering, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, Crystallography, Monomer, PACS : 61.10.Eq81.10.Dn87.15.Kg, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Radius of gyration, 0210 nano-technology
Abstract

International audience; A combination of small angle X-ray scattering (SAXS) and gel techniques was used to follow the kinetics of aprotinin (BPTI) nucleation and crystal growth induced in NaCl solutions by increasing temperature. These experiments were carried out in order to determine if aggregation occurs in the solution during crystal growth. From these first series of experiments, we found a radius of gyration of 24.7 Å for intermediates species in solution, consistent with a mixture of decamers and monomers. Once formed, BPTI crystals obtained at acidic pH in NaCl kept this association and it is the decamer, which was found in the crystal packing in contrast to what happened at basic pH where only monomers are observed in the crystal.

Published
2002

38. The Potential of Mean Force concept for bridging (length and time) scales in the modeling of complex porous materials

Author

Roland J.-M. Pellenq, Katerina Ioannidou, Benoit Carrier, Matthieu Vandamme, Massachusetts Institute of Technology (MIT), Modélisation et expérimentation multi-échelle pour les solides hétérogènes (multi-échelle), Laboratoire Navier (navier umr 8205), École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR), École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS), and Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics::Biological Physics, Quantitative Biology::Biomolecules, Engineering, Bridging (networking), Scale (ratio), business.industry, Physics, QC1-999, Mechanical engineering, 02 engineering and technology, Function (mathematics), 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Key (cryptography), Statistical physics, Potential of mean force, 0210 nano-technology, business, Porous medium, Energy (signal processing)
Abstract

International audience; We introduce the concept of Potential of Mean Force, PMF, as a way to implement upscaling modeling from the nano-scale to micron-scale. A PMF is a free energy function representing in an effective way the interactions between objects (cement hydrates, clay platelets, etc.) at thermodynamics conditions. The PMF is therefore the key piece of information allowing to coarse-grained Physical-Chemistry information in a meso-scale model formulation. The use of PMF offers a huge computational advantage as it allows a straight up-scaling to the meso-scale while keeping essential interactions information that are the hallmark of Physical-Chemistry processes. Such a coarse-grained modeling integrates atomistic response into inter-particle potentials that fully propagate molecular scale information all the way to the meso-scale.

Published
2017

39. Kinetic modeling of the CO oxidation reaction on supported metal clusters

Author

Laurent Piccolo, Conrad Becker, Claude Henry, Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn, and Piccolo, Laurent

Subjects
Materials science, Analytical chemistry, chemistry.chemical_element, 02 engineering and technology, 010501 environmental sciences, 010402 general chemistry, Kinetic energy, 01 natural sciences, Redox, Oxygen, Reaction rate, Atom, Reactivity (chemistry), Physics::Chemical Physics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, [CHIM.CATA] Chemical Sciences/Catalysis, [CHIM.CATA]Chemical Sciences/Catalysis, 021001 nanoscience & nanotechnology, Atomic and Molecular Physics, and Optics, 010406 physical chemistry, 0104 chemical sciences, chemistry, Particle, 0210 nano-technology, Molecular beam
Abstract

The CO oxidation on Pd is generally considered to be structure insensitive and is not expected to depend on the size of the Pd particles. However, several size effects have already been evidenced for this reaction. Near the temperature where the steady-state reaction rate is maximum, the reactivity per Pd surface atom (turnover number (TON)) increases for small particles. At low temperature, in transient molecular beam experiments, a second peak of CO2 appears after the CO beam is closed, while the oxygen is still supplied to the sample. This peak shifts, and its shape changes with temperature and oxygen pressure. This peak is explained by the presence of CO strongly bound to the particle edges. This strongly bound CO reactswell after the CO adsorbed on the facets has desorbed. A kinetic model is presented which explains the evolution of this peak with temperature and oxygen pressure.

Published
1999

40. Fabrication and characterization of large metallic nanodots arrays for organic thin film solar cells using anodic aluminum oxide templates

Author

Eric Moyen, Lionel Patrone, Virginie Chevallier, Alexandre Sangar, Sylvain Vedraine, Francois Flory, Gregory Delafosse, Ludovic Escoubas, Alexandre Merlen, Margrit Hanbücken, Philippe Torchio, Equipes Öpto-PV\' et \'Nanostructuration\', Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique de l'ENS Lyon (Phys-ENS), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), OPTO-PV, Equipe Optoélectronique et Photovoltaïque, OptoPV, Laboratoire matériaux et microélectronique de Provence (L2MP), Université Paul Cézanne - Aix-Marseille 3-Université de Provence - Aix-Marseille 1-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), École normale supérieure - Lyon (ENS Lyon)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon, and Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)

Subjects
Materials science, Fabrication, Organic solar cell, Nanotechnology, 02 engineering and technology, Substrate (electronics), 010402 general chemistry, 01 natural sciences, Anodic aluminum oxide, [SPI]Engineering Sciences [physics], Organic Photovoltaic cell, Plasmonic solar cell, Surface plasmon resonance, Plasmon, Renewable Energy, Sustainability and the Environment, Surface-enhanced Raman spectroscopy, 021001 nanoscience & nanotechnology, Plasmonic, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Near field, Nanoparticles, Nanodot, FDTD method calculation, 0210 nano-technology
Abstract

International audience; We present a soft method for the fabrication of well controlled plasmonic nanodots on large ITO substrate for organic solar cells. Masks of nanopatterned aluminum oxide are elaborated and deposited on ITO substrates before metal deposition. After removal of the mask, well organized and isolated metallic nanodots are observed. In this article, we focus on gold or silver nanostructures: they show a Surface Plasmon Resonance (SPR) in the visible region, an important feature for their integration in organic thin film solar cells and the final improvement of the optical properties of the cell. In addition, their near field enhancement capacity is also clearly demonstrated by surface enhanced Raman spectroscopy and FDTD method simulation. An additional advantage of this protocol is that it can be used on any kind of surface and with different metals, depending on the final application.

Published
2013

41. Role of Quantum Confinement in Luminescence Efficiency of Group IV Nanostructures

Author

David J. Lockwood, Guillaume Amiard, R. N. Costa Filho, Nelson Rowell, E. G. Barbagiovanni, David Grosso, Luc Favre, Marco Faustini, Isabelle Berbezier, A. Ronda, Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie de la Matière Condensée de Paris (site Paris VI) (LCMCP (site Paris VI)), Université Pierre et Marie Curie - Paris 6 (UPMC)-Collège de France (CdF (institution))-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)

Subjects
Physics, Photoluminescence, Nanostructure, Condensed Matter - Mesoscale and Nanoscale Physics, Scattering, General Physics and Astronomy, FOS: Physical sciences, 02 engineering and technology, Electron, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Effective mass (solid-state physics), Quantum dot, 0103 physical sciences, Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Atomic physics, 010306 general physics, 0210 nano-technology, Luminescence, Bohr radius
Abstract

International audience; Experimental results obtained previously for the photoluminescence efficiency (PLeff) of Ge quantum dots (QDs) are theoretically studied. A log-log plot of PLeff versus QD diameter (D) resulted in an identical slope for each Ge QD sample only when E-G similar to (D-2 + D)(-1). We identified that above D approximate to 6.2 nm: E-G similar to D-1 due to a changing effective mass (EM), while below D approximate to 4.6 nm: E-G similar to D-2 due to electron/hole confinement. We propose that as the QD size is initially reduced, the EM is reduced, which increases the Bohr radius and interface scattering until eventually pure quantum confinement effects dominate at small D. (C) 2014 AIP Publishing LLC.

Published
2013
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42. Effects of anisotropy on the equilibrium shape of nanoscale pores at grain boundaries

Author

Dominique Chatain, Paul Wynblatt, Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), and Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Work (thermodynamics), Materials science, Polymers and Plastics, Nucleation, 02 engineering and technology, 01 natural sciences, Crystal, Molecular dynamics, Nanopores, Atomistic simulation, 0103 physical sciences, morphology, Triple line, Facet, Anisotropy, 010302 applied physics, Metals and Alloys, 021001 nanoscience & nanotechnology, Electronic, Optical and Magnetic Materials, Crystallography, Nanopore, Chemical physics, triple line 2, Grain boundaries, Ceramics and Composites, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Grain boundary, 0210 nano-technology
Abstract

Molecular dynamics simulations have been performed to study the interaction between a faceted pore and an anisotropic grain boundary (GB). Nickel was chosen as a convenient model system. In order to establish the equilibrium crystal shape (ECS) of the pore, studies were also conducted on isolated pores. Isolated pores were found to be subject to the nucleation inhibition of equilibration that has been predicted by Rohrer et al. (J Am Ceram Soc 2000;83:214, 2001;84: 2099). This work shows that configurations close to the ECS can be obtained if supersaturation within a pore is artificially increased by adding mobile adatoms to the internal surfaces of the pores. In the case of pores located at GBs, the nucleation energy barriers to facet displacement are not present for facets in contact with the GB at the triple line, but may still persist for facets that have no contact with the GB. This problem can be overcome by approaching the equilibrium shape from different initial configurations. The configuration of the GB in the vicinity of the pore has been found to be essentially planar, indicating that GB puckering in the vicinity of anisotropic pores is not generally necessary. The present calculations show that incompatibilities between misoriented pore facets that meet at the triple line with the GB are easily accommodated by local atomic rearrangements at the disordered region of intersection with the GB.

Published
2013

43. Adsorption, intrusion and freezing in porous silica: the view from the nanoscale

Author

Roland J.-M. Pellenq, Francesco Di Renzo, Benoit Coasne, Anne Galarneau, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Department of Civil and Environmental Engineering [Cambridge] (CEE), Massachusetts Institute of Technology (MIT), Multi-Scale Material Science for Energy and Environment ((MSC)2 UMI3466 CNRS-MIT), CNRS-MIT, Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), and Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Work (thermodynamics), Materials science, Surface Properties, Evaporation, Nanotechnology, 02 engineering and technology, Molecular Dynamics Simulation, 010402 general chemistry, 01 natural sciences, Physics::Geophysics, Adsorption, Freezing, Porosity, Nanoscopic scale, Capillary condensation, General Chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, Silicon Dioxide, 021001 nanoscience & nanotechnology, Nanostructures, 0104 chemical sciences, Characterization (materials science), Condensed Matter::Soft Condensed Matter, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Chemical physics, Cavitation, 0210 nano-technology
Abstract

International audience; This review presents the state of the art of molecular simulation and theory of adsorption, intrusion and freezing in porous silica. Both silica pores of a simple geometry and disordered porous silicas which exhibit morphological and topological disorders are considered. We provide a brief description of the numerical models of porous silicas available in the literature and present the most common molecular simulation and theoretical methods. Adsorption in regular and irregular pores is discussed in the light of classical theories of adsorption and capillary condensation in pores. We also present the different evaporation mechanisms for disordered systems: pore blocking and cavitation. The criticality of fluids confined in pores, which is still the matter of debate, is then discussed. We review theoretical results for intrusion/extrusion and freezing in silica pores and discuss the validity of classical approaches such as the Washburn-Laplace equation and Gibbs-Thomson equation to describe the thermodynamics of intrusion and in-pore freezing. The validity of the most widely used characterization techniques is then discussed. We report some concluding remarks and suggest directions for future work.

Published
2013

44. Phase formation during Mn thin film reaction with Ge: Self-aligned germanide process for spintronics

Author

Christophe Girardeaux, V. Le Thanh, Alain Portavoce, Omar Abbes, Lisa Michez, Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Cinam, Hal, and Girardeaux, Christophe

Subjects
010302 applied physics, Diffraction, Materials science, Physics and Astronomy (miscellaneous), Spintronics, business.industry, Metallurgy, 02 engineering and technology, 021001 nanoscience & nanotechnology, Salicide, 01 natural sciences, [PHYS.COND.CM-MS] Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Amorphous solid, Germanide, chemistry.chemical_compound, chemistry, 0103 physical sciences, X-ray crystallography, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Optoelectronics, Thin film, 0210 nano-technology, business, Layer (electronics), ComputingMilieux_MISCELLANEOUS
Abstract

Interesting results have been reported concerning the magnetic properties of the Mn5Ge3 compound, opening the road to possibly create spin injectors in Ge. However, a process compatible with the Complementary Metal Oxide Semiconductor technology, allowing to produce a Mn5Ge3 layer on the active regions of Ge-based transistors has not been well established yet. Here, we report on the solid state reaction between a 50 nm-thick Mn film and amorphous Ge, aiming to investigate a similar process than the one (Salicide) used for contact production in the standard Si technology. In situ X-ray diffraction combined with ex situ structural and magnetic characterizations were used to identify and study phase formation during the Mn/Ge reaction.

Published
2013

45. Manganese diffusion in monocrystalline germanium

Author

Lee Chow, Yauheni Rudzevich, Omar Abbes, V. Le Thanh, Alain Portavoce, Christophe Girardeaux, Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Girardeaux, Christophe, Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), and Cinam, Hal

Subjects
Materials science, Diffusion, Inorganic chemistry, Analytical chemistry, chemistry.chemical_element, Germanium, 02 engineering and technology, Substrate (electronics), Manganese, 01 natural sciences, Vacancy defect, 0103 physical sciences, General Materials Science, 010306 general physics, ComputingMilieux_MISCELLANEOUS, Mechanical Engineering, Doping, Metals and Alloys, 021001 nanoscience & nanotechnology, Condensed Matter Physics, [PHYS.COND.CM-MS] Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Secondary ion mass spectrometry, chemistry, Mechanics of Materials, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], 0210 nano-technology, Molecular beam epitaxy
Abstract

The diffusion of a half monolayer of Mn deposited by molecular beam epitaxy on a Ge(0 0 1) substrate was studied via secondary ion mass spectrometry. Mn diffused in Ge under extrinsic conditions, exhibiting a solubility of 0.7–0.9%. All the Mn atoms were activated, occupying Ge substitutional sites and exhibiting a negative charge, in agreement with semiconductor doping theory. The diffusion mechanism being vacancy ( V )-mediated, the formation of Mn– V pairs is suggested. Mn surface desorption occurred for temperatures >600 °C.

Published
2012

46. On Morphology and Strain Field of Ge/Si(001) Islands According to TEM Phase Imaging Method

Author

Antoine Ronda, T. Neisius, P. Donnadieu, A. Gouyé, Guillaume Amiard, Isabelle Berbezier, Science et Ingénierie des Matériaux et Procédés (SIMaP), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National Polytechnique de Grenoble (INPG)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), STMicroelectronics [Crolles] (ST-CROLLES), Centre de recherche de la matière condensée et des nanosciences (CRMCN), and Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Strain (chemistry), Relaxation (NMR), Biomedical Engineering, Nucleation, chemistry.chemical_element, Bioengineering, Geometry, Germanium, 02 engineering and technology, General Chemistry, Substrate (electronics), [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Dome (geology), chemistry, Phase (matter), 0103 physical sciences, General Materials Science, 010306 general physics, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS, Pyramid (geometry)
Abstract

The mechanism driving Germanium islands nucleation and self-assembly is an important effect for opto-electronic applications, still not fully understood. We demonstrate that the new transmission electron microscopy phase imaging method provides insights on the distribution of strain and composition fields in and around the islands on rather large areas. The method consists of retrieving the phase from a focus series of plane view images. The phase image is representative of morphology, composition and strain. The results show that whatever the islands size and shape is, a maximum compressive strain is obtained at the apex of the islands compensated by a maximum tensile strain in the substrate close to the islands perimeter. The maximum compressive strain is associated to a larger Ge concentration. The distribution of tensile strain varies with the shape of the islands: for square base pyramidal "hut" islands, a maximum tensile strain is obtained at the four corners of the pyramid base and for "dome" islands, the tensile strain is less pronounced and affects almost the whole island perimeter. These results are consistent with the higher strain relaxation level of "dome" islands in comparison to those of "hut" islands.

Published
2011

47. AAO-based nanoreservoir arrays: A quick and easy support for TEM characterization

Author

Houda Sahaf, F. Bedu, Margrit Hanbücken, Laurence Masson, Magali Macé, Eric Moyen, Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), and MASSON, Laurence

Subjects
Fabrication, Materials science, General Physics and Astronomy, Nanoparticle, Nanotechnology, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, [PHYS.COND.CM-MS] Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Characterization (materials science), chemistry.chemical_compound, chemistry, Transmission electron microscopy, 0103 physical sciences, Aluminium oxide, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Sample preparation, Nanometre, 010306 general physics, 0210 nano-technology, Deposition (law), ComputingMilieux_MISCELLANEOUS
Abstract

Large-scale arrays of calibrated, nanometer sized reservoirs are prepared by adapting the well-established electrochemical method used so far for the preparation of anodic aluminium oxide (AAO) membranes. The bottom plane of the assembly is prepared to be transparent for high-energy electrons, enabling their use as a universal sample support for transmission electron microscopy studies of nanoparticles. The nanoreservoir substrates can be cleaned under ultra-high-vacuum conditions and filled, by evaporating different materials. Filled nanoreservoirs can locally be sealed with a thin carbon layer using focused-ion-beam–induced deposition (FIBID). Nanoparticles, grow at various adsorption places on the walls and bottom planes inside the nanoreservoirs. They can be characterized by transmission electron microscopy (TEM) without further sample preparation in different crystallographic directions. Due to the dense array-arrangement of the reservoirs, very good statistics can already be obtained on one single sample. The controlled fabrication of the nanoreservoir array and first TEM results obtained on Au nanoparticles before and after sealing of the reservoirs, are presented.

Published
2010

48. Molecular Simulation of Nitrogen Adsorption in Nanoporous Silica

Author

Benoit Coasne, Roland J.-M. Pellenq, F. Di Renzo, Anne Galarneau, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), and Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
chemistry.chemical_element, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Adsorption, MCM-41, Desorption, Electrochemistry, Organic chemistry, General Materials Science, Spectroscopy, Capillary condensation, Nanoporous, Chemistry, Condensation, Surfaces and Interfaces, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Nitrogen, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Nanopore, Chemical engineering, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], 0210 nano-technology
Abstract

International audience; This article reports on a molecular simulation study of nitrogen adsorption and condensation at 77 K in atomistic silica cylindrical nanopores (MCM-41). Two models are considered for the nitrogen molecule and its interaction with the silica substrate. In the “pea” model, the nitrogen molecule is described as a single Lennard-Jones sphere and only Lennard-Jones interactions between the nitrogen molecule and the oxygens atoms of the silica substrate are taken into account. In the “bean” model (TraPPE force field), the nitrogen molecule is composed of two Lennard-Jones sites and a linear array of three charges on the atomic positions and at the center of the nitrogen-nitrogen bond. In the bean model, the interactions between the sites on the nitrogen molecule and the Si, O, and H atoms of the substrate are the sum of the Coulombic and dispersion interactions with a repulsive short-range contribution. The data obtained with the pea and bean models in silica nanopores conform to the typical behavior observed in the experiments for adsorption/ condensation in cylindrical MCM-41 nanopores; the adsorbed amount increases continuously in the multilayer adsorption regime until an irreversible jump occurs because of capillary condensation and evaporation of the fluid within the pore. Our results suggest that the pea model can be used for characterization purposes where one is interested in capturing the global experimental behavior upon adsorption and desorption in silica nanopores. However, the bean model is more suitable to investigating the details of the interaction with the surface because this model, which accounts for the partial charges located on the nitrogen atoms of the molecule (quadrupole), allows a description of the specific interactions between this adsorbate and silica surfaces (silanol groups and siloxane bridges) or grafted silica surfaces. In particular, the bean model provides a more realistic picture of nitrogen adsorption in the vicinity of silica surfaces or confined in silica nanopores, where the isosteric heat of adsorption curves show that the nitrogen molecule in this model is sensitive to the surface heterogeneity.

Published
2010

49. Direct observation of the reversible changes of the morphology of Pt nanoparticles under gas environment

Author

Suzanne Giorgio, Martiane Cabié, K. Philippot, Claude Raymond Henry, B. Chaudret, M. Rosa Axet, Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), departament de quimica fisica i quimica inorganica i quimica analitica i quimica organica, Universitat Rovira i Virgili, 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), 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, and Cinam, Hal

Subjects
Morphology (linguistics), Hydrogen, chemistry.chemical_element, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Oxygen, Crystal, Adsorption, [CHIM]Chemical Sciences, Physical and Theoretical Chemistry, Anisotropy, ComputingMilieux_MISCELLANEOUS, Chemistry, [CHIM.CATA]Chemical Sciences/Catalysis, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Surface energy, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Crystallography, General Energy, Chemical engineering, Transmission electron microscopy, 0210 nano-technology
Abstract

Large faceted Pt particles prepared in solution were in situ observed by ETEM (Environmental Transmission Electron Microscopy) during oxidation - reduction cycles. Reversible shape transformations were observed with the increase or decrease of the ratio of (111) faces to (001) faces in H2 and O2 respectively, at pressures of a few mbars. Under Hydrogen, the shape is relatively close to the Wulff shape of an fcc crystal under vacuum, while under oxygen, the (001) faces extend and the (111) faces shrink due to a stronger adsorption of oxygen on the more open (100) faces. Going from hydrogen to oxygen, the surface energy anisotropy is inverted.

Published
2010

50. Correction of secondary ion mass spectrometry profiles for atom diffusion measurements

Author

Catherine Grosjean, Rachid Daineche, Nicolas Rodriguez, Alain Portavoce, Christophe Girardeaux, Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), University of Granada [Granada], Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Universidad de Granada = University of Granada (UGR), Département Systèmes et Architectures Sécurisés (SAS-ENSMSE), École des Mines de Saint-Étienne (Mines Saint-Étienne MSE), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-CMP-GC, Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), STMicroelectronics [Rousset] (ST-ROUSSET), and Girardeaux, Christophe

Subjects
Static secondary-ion mass spectrometry, Materials science, Ion beam, Analytical chemistry, 02 engineering and technology, 01 natural sciences, Si(001), Diffusion, Ion beam deposition, Characterization methods, 0103 physical sciences, Atom, General Materials Science, Diffusion (business), As, ComputingMilieux_MISCELLANEOUS, 010302 applied physics, Mechanical Engineering, 021001 nanoscience & nanotechnology, Condensed Matter Physics, [PHYS.COND.CM-MS] Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], [SPI.TRON]Engineering Sciences [physics]/Electronics, Secondary ion mass spectrometry, Mechanics of Materials, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Atomic physics, 0210 nano-technology, SIMS, Simulation
Abstract

International audience; A simple method is proposed in order to correct experimental secondary ion mass spectrometry (SIMS) profiles. This method uses only one parameter which is experimentally accessible. It is tested in the case of As SIMS profiles in Si(001) acquired with three different primary ion beam energies: 1, 3, and 9 keV. This method is shown to give consistent corrections. The correction of SIMS profiles measured in a same sample with different analysis conditions leads to the same As distribution.

Published
2009

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