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213 results on '"Mariot, J-M"'

1. Bi monocrystal formation on InAs(111)A and B substrates

Author

Nicolaï, L., Mariot, J. -M., Djukic, U., Wang, W., Heckmann, O., Richter, M. C., Kanski, J., Leandersson, M., Sadowski, J., Balasubramanian, T., Vobornik, I., Fujii, J., Braun, J., Ebert, H., Minár, J., and Hricovini, K.

Subjects
Condensed Matter - Materials Science
Abstract

The growth of Bi films deposited on both A and B faces of InAs(111) has been investigated by low-energy electron diffraction, scanning tunneling microscopy, and photoelectron spectroscopy using synchrotron radiation. The changes upon Bi deposition of the In 4d and Bi 5d5/2 photoelectron signals allow to get a comprehensive picture of the Bi/InAs(1 1 1) interface. From the initial stages the Bi growth on the A face (In-terminated InAs) is epitaxial, contrary to that on the B face (As- terminated InAs) that proceeds via the formation of islands. Angle-resolved photoelectron spectra show that the electronic structure of a $\approx 10$~BL deposit on the A face is identical to that of bulk Bi, while more than $\approx 30$ BL are needed for the B face. Both bulk and surface states are well accounted for by fully relativistic ab initio spin-resolved photoemission calculations., Comment: 7 pages, 7 figures

Published
2018

2. Distinctive Picosecond Spin Polarization Dynamics in Bulk Half-Metals

Author

Battiato, M., Minar, J., Wang, W., Ndiaye, W., Richter, M. C., Heckmann, O., Mariot, J. -M., Parmigiani, F., Hricovini, K., and Cacho, C.

Subjects
Condensed Matter - Materials Science
Abstract

Femtosecond laser excitations in half-metal (HM) compounds are theoretically predicted to induce an exotic picosecond spin dynamics. In particular, conversely to what is observed in conventional metals and semiconductors, the thermalization process in HMs leads to a long living partially thermalized configuration characterized by three Fermi--Dirac distributions for the minority, majority conduction and majority valence electrons respectively. Remarkably, these distributions have the same temperature but different chemical potentials. This unusual thermodynamics state causes a persistent non-equilibrium spin polarization only well above the Fermi energy. Femtosecond spin dynamics experiments performed on Fe$_3$O$_4$ by time-, spin-, and angle-resolved photoelectron spectroscopy confirm our model. Furthermore, the spin polarization response proves to be very robust and it can be adopted to selectively test the bulk HM character in a wide range of compounds.

Published
2018
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3. Hard x-ray spectroscopy in NaxCoO2 and superconducting NaxCoO2 - yH2O: A view on the bulk Co electronic properties

Author

Leininger, Philippe, Rueff, J. -P., Mariot, J. -M., Yaresko, A., Proux, O., Hazemann, J. -L., Vanko, G., Sasaki, T., and Ishii, H.

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

The electronic properties of Co in bulk Na0.7CoO2 and the superconducting hydrated compound Na0.35CoO2 - y H2O have been investigated by x-ray absorption spectroscopy (XAS) and resonant inelastic x-ray scattering (RIXS) using hard x-rays. The XAS spectra at the Co K-edge were measured in both compounds with two different polarization directions. The changes in the XAS spectra upon hydration and their polarization dependence are well accounted for by linear muffin- tin orbital calculations in the local density approximation. The underlying electronic structure indicates the strong hybridization between the Co 3d and O 2p states in both compounds, while the electron localization is enhanced in the hydrated compound due to the increase of the Co-Co interplanar distance. The Co K pre-edge further highlights the splitting of the d band as a result of the crystal field effect and demonstrates the Co valency increase when Na0.7CoO2 is hydrated. The RIXS spectra measured at the Co K-edge show an energy loss feature around 10 eV in both compounds in fair agreement with the calculated dynamical structure factor. The RIXS feature is associated to a damped plasmon excitation., Comment: 8 pages

Published
2006
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4. Probing the gamma-alpha Transition in Bulk Ce under Pressure: A Direct Investigation by Resonant Inelastic X-ray Scattering

Author

Rueff, Jean-Pascal, Itié, Jean-Paul, Taguchi, M., Hague, C. F., Mariot, J. -M., Delaunay, R., Kappler, J. -P., and Jaouen, N.

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

We report on the most complete investigation to date of the 4f-electron properties at the gamma-alpha transition in elemental Ce by resonant inelastic x-ray scattering (RIXS). The Ce 2p3d-RIXS spectra were measured directly in the bulk material as a function of pressure through the transition. The spectra were simulated within the Anderson impurity model. The occupation number nf was derived from the calculations in both gamma- and alpha-phases in the ground state along with the f doubleoccupancy. We find that the electronic structure changes result mainly from band formation of 4f electrons which concurs with reduced electron correlation and increased Kondo screening at high pressure., Comment: 4 pages

Published
2006
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6. Band dispersion within pristine InBi crystal

Author

Nicolaï, L, Minár, J, Richter, M, Heckmann, O, Fanciulli, M, Reddy, L, Bell, G, Haria, R, Mariot, J.-M, Hricovini, K, Mariot, J.-M., New Technologies Research Centre [Plzeň] (NTC), University of West Bohemia [Plzeň ], Laboratoire de Physique des Matériaux et des Surfaces (LPMS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CY Cergy Paris Université (CY), Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Dynamique et Interactions en phase Condensée (DICO), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), University of Warwick [Coventry], Laboratoire de Chimie Physique - Matière et Rayonnement (LCPMR), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and J. Vajda, I. Jamnický, and P. Novák

Subjects
[PHYS]Physics [physics], [PHYS] Physics [physics]
Abstract

International audience; InBi has been theoretically analysed for many years as a semi-metal showing a stable phase within the PbO structure thanks to spin-orbit coupling forces . Regrettably, this alloy system remains not well-known on the experimental side: reports of grown ordered crystals are rare. We here present a thorough experimental and ab initio theoretical analysis on InBi(001). The crystal was grown using the Bridgman-Stockbarger technique. InBi consists of In layers sandwiched between Bi monolayers, with weak Van der Waals bonds amid the resulting trilayers. The InBi crystal was cleaved in situ in order to obtain a clean and flat surface suitable for angleresolved photoemission measurements. The SPR-KKR package , based on the Dirac equation, which fundamentally includes relativistic effects, was used for the theoretical analysis and clearly underlines the influence of the surface termination.

Published
2022

7. Mn 5Ge 3 films grown on Ge(1 1 1)- c(2 × 8)

Author

De Padova, P., Mariot, J.-M., Favre, L., Berbezier, I., Olivieri, B., Perfetti, P., Quaresima, C., Ottaviani, C., Taleb-Ibrahimi, A., Le Fèvre, P., Bertran, F., Heckmann, O., Richter, M.C., Ndiaye, W., D'Orazio, F., Lucari, F., Cacho, C.M., and Hricovini, K.

Published
2011
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14. Bi ultra-thin crystalline films on InAs(1 1 1)A and B substrates: a combined core-level and valence-band angle-resolved and dichroic photoemission study

Author

Nicolaï, L, primary, Mariot, J-M, additional, Djukic, U, additional, Wang, W, additional, Heckmann, O, additional, Richter, M C, additional, Kanski, J, additional, Leandersson, M, additional, Balasubramanian, T, additional, Sadowski, J, additional, Braun, J, additional, Ebert, H, additional, Vobornik, I, additional, Fujii, J, additional, Minár, J, additional, and Hricovini, K, additional

Published
2019
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17. Bi ultra-thin crystalline films on InAs(111)A and B substrates : a combined core-level and valence-band angle-resolved and dichroic photoemission study

Author

Nicolai, L., Mariot, J-M, Djukic, U., Wang, W., Heckmann, O., Richter, M. C., Kanski, J., Leandersson, M., Balasubramanian, T., Sadowski, Janusz, Braun, J., Ebert, H., Vobornik, I., Fujii, J., Minar, J., Hricovini, K., Nicolai, L., Mariot, J-M, Djukic, U., Wang, W., Heckmann, O., Richter, M. C., Kanski, J., Leandersson, M., Balasubramanian, T., Sadowski, Janusz, Braun, J., Ebert, H., Vobornik, I., Fujii, J., Minar, J., and Hricovini, K.

Abstract

The growth of Bi on both the In-terminated (A) face and the As-terminated (B) face of InAs(111) has been investigated by low-energy electron diffraction, scanning tunnelling microscopy, and photoelectron spectroscopy using synchrotron radiation. The changes upon Bi deposition of the In 4d and Bi 5d(5/2) photoelectron signals allow to get a comprehensive picture of the Bi/InAs(111) interface. From the early stage the Bi growth on the A face is epitaxial, contrary to that on the B face that proceeds via the formation of islands. Angle-resolved photoelectron spectra show that the electronic structure of a Bi deposit of approximate to 10 bi-layers on the A face is identical to that of bulk Bi, while more than approximate to 30 bi-layers are needed for the B face. Both bulk and surface electronic states observed are well accounted for by fully relativistic ab initio calculations performed using the one-step model of photoemission. These calculations are used to analyse the dichroic photoemission data recorded in the vicinity of the Fermi level around the (Gamma) over bar point of the Brillouin zone.

Published
2019
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18. Near-surface defects created by 335 nm laser irradiation of rutile

Author

Mercier, T. Le, Quarton, M., Fontaine, M.-F., Hague, C.F., and Mariot, J.-M.

Subjects
Rutile -- Research, Irradiation -- Analysis, Lasers -- Research, Physics
Abstract

X-ray photoelectron spectroscopy and exposure of sintered disks of rutile TiO2 to a 355-nanometer laser beam reveal that triply ionized Ti is formed at a depth of 0.4 micrometers below the surface of TiO2 due to strong energy deposition on the surface. The ions reduce the electrical resistivity of the TiO2 from 10 to the power of 9 Ohm-centimeters to 10 Ohm-centimeters. The reduction occurs through the formation of the energy levels in the gap by the triply ionized Ti.

Published
1994

26. k dependence of the spin polarization in Mn5Ge3/Ge(111) thin films

Author

Ndiaye, W., Mariot, J. -M., De Padova, P., Richter, M. C., Wang, W., Heckmann, O., Taleb-Ibrahimi, A., Le Fevre, P., Bertran, F., Cacho, C., Leandersson, M., Balasubramanian, T., Stroppa, A., Picozzi, S., and Hricovini, K.

Subjects
thin film spin polarization
Abstract

Mn5Ge3(001) thin films grown on Ge(111) were studied by angle-and spin-resolved photoemission using synchrotron radiation in the 17-40 eV photon energy range. The photoelectron spectra were simulated starting from a first-principles band-structure calculation for the ground state, using the free-electron approximation for the final states, taking into account photohole lifetime effects and k(perpendicular to) broadening plus correlation effects, but ignoring transition matrix elements. The measured spin polarizations for the various k points investigated in the Gamma MLA plane of the Brillouin zone are found to be in fair enough agreement with the simulated ones, providing a strong support to the ground-state band-structure calculations. Possible origins for the departures between either simulations and experiments or previous and present experiments are discussed.

Published
2015

31. k dependence of the spin polarization inMn5Ge3/Ge(111)thin films

Author

Ndiaye, W., primary, Mariot, J.-M., additional, De Padova, P., additional, Richter, M. C., additional, Wang, W., additional, Heckmann, O., additional, Taleb-Ibrahimi, A., additional, Le Fèvre, P., additional, Bertran, F., additional, Cacho, C., additional, Leandersson, M., additional, Balasubramanian, T., additional, Stroppa, A., additional, Picozzi, S., additional, and Hricovini, K., additional

Published
2015
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35. NiFe2O4 and Fe3O4 studied by XMCD and resonant photoemission

Author

Richter M.C., Mariot J.-M., Heckmann O., Kjeldgaard L., Mun B.S., Fadley C.S., Lueders U., Bobo J.-F., De Padova P., Taleb-Ibrahimi A., and Hricovini K.

Abstract

X-ray magnetic circular dichroism and resonant photoemission at the Fe and Ni L-2,L-3 edges have been used to investigate the electronic structure of NiFe2O4 (NFO) thin films. The results, when compared to those obtained on Fe3O4, indicate that in a 12 nm NFO film the Ni atoms occupy mainly B sites, as in bulk NFO, and that a decrease in the thickness of the film results in a modification of the nickel hybridization

Published
2009

36. Charge transfer at the metal-insulator transition in V2O3 thin films by resonant inelastic x-ray scattering

Author

Hague, C., Mariot, J.-M., Ilakovac, V., Delaunay, R., Marsi, M., Sacchi, M., Rueff, Jean-Pascal, Felsch, W., Laboratoire de Chimie Physique - Matière et Rayonnement (LCPMR), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique des Solides (LPS), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), and Georg-August-University = Georg-August-Universität Göttingen

Subjects
[PHYS.COND.CM-SCE]Physics [physics]/Condensed Matter [cond-mat]/Strongly Correlated Electrons [cond-mat.str-el]
Published
2008

37. Mn0.06Ge0.94 diluted magnetic semiconductor epitaxially grown on Ge(001): Influence of Mn5Ge3 nanoscopic clusters on the electronic and magnetic properties

Author

De Padova P. (1), Ayoub J.P. (2), Berbezier I. (2), Perfetti P. (1), Quaresima C. (1), Testa A.M. (1), Fiorani D. (1), Olivieri B. (3), Mariot J.-M. (4), Taleb-Ibrahimi A. (5), Richter M.C. (6), Heckmann O. (6), and Hricovini K. (6)

Abstract

The structural, electronic, and magnetic properties of the Mn0.06Ge0.94 diluted magnetic semiconductor, grown at 520 K by molecular-beam epitaxy on Ge(001)2x1, have been investigated. Diluted and highly ordered alloys, containing Mn5Ge3 nanocrystals, were grown. The valence band photoelectron spectrum of Mn0.06Ge0.94 shows a feature located at -4.2 eV below the Fermi level, which is the fingerprint of substitutional Mn atoms in the Ge matrix. Magnetization measurements show the presence of a paramagnetic component due to substitutional Mn atoms and of a ferromagneticlike component due to Mn5Ge3 nanocrystallites. The Mn L-2,L-3 x-ray absorption spectrum of this polyphase film shows no marked multiplet structure, but a bandlike character.

Published
2008

39. Hard x-ray spectroscopy in Na x Co O 2 and superconducting Na x Co O 2 ∙ y H 2 O : Bulk Co electronic properties

Author

Leininger, Ph., Rueff, Jean-Pascal, Mariot, J.-M., Yaresko, A., Proux, Olivier, Hazemann, J.-L., Vanko, G., Sasaki, T., Ishii, H., Laboratoire de Chimie Physique - Matière et Rayonnement (LCPMR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université Pierre et Marie Curie - Paris 6 (UPMC), Max Planck Institute for Solid State Research, Max-Planck-Gesellschaft, Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Institute of Electrical Engineering, SAS Bratislava, Institute for Material Research (IMR), Tohoku University [Sendai], RIKEN SPring-8 Center [Hyogo] (RIKEN RSC), RIKEN - Institute of Physical and Chemical Research [Japon] (RIKEN), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), SPring-8 (SPRING-8), and Japan Synchrotron Radiation Research Institute (JASRI)

Subjects
number͑s͒: 7870Dm, Condensed Matter::Materials Science, 7120Ϫb, Condensed Matter::Strongly Correlated Electrons, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], 7870Ck, 7120Be
Abstract

International audience; The electronic properties of Co in bulk Na 0.7 CoO 2 and the superconducting hydrated compound Na 0.35 CoO 2 · yH 2 O have been investigated by x-ray absorption spectroscopy ͑XAS͒ and resonant inelastic x-ray scattering ͑RIXS͒ using hard x rays. The XAS spectra at the Co K-edge were measured in both compounds with two different polarization directions. The changes in the XAS spectra upon hydration and their polarization dependence are well accounted for by linear muffin-tin orbital calculations in the local density approximation. The underlying electronic structure indicates the strong hybridization between the Co 3d and O 2p states in both compounds, while the electron localization is enhanced in the hydrated compound due to the increase of the Co-Co interplanar distance. The Co K preedge further highlights the splitting of the d band as a result of the crystal field effect and demonstrates the Co valency increase when Na 0.7 CoO 2 is hydrated. The RIXS spectra measured at the Co K edge show an energy loss feature around 10 eV in both compounds, in fair agreement with the calculated dynamical structure factor. The RIXS feature is associated to a damped plasmon excitation.

Published
2006

40. f -State Occupancy at the γ − α Phase Transition of Ce-Th and Ce-Sc Alloys

Author

Rueff, Jean-Pascal, Hague, C., Mariot, J.-M., Journel, L., Delaunay, R., Kappler, J.-P., Schmerber, G., Derory, A., Jaouen, N., Krill, G., Laboratoire de Chimie Physique - Matière et Rayonnement (LCPMR), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), RIKEN - Institute of Physical and Chemical Research [Japon] (RIKEN), Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), European Synchroton Radiation Facility [Grenoble] (ESRF), Laboratoire pour l'utilisation du rayonnement électromagnétique (LURE), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-MENRT-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.COND.CM-SCE]Physics [physics]/Condensed Matter [cond-mat]/Strongly Correlated Electrons [cond-mat.str-el]
Published
2004

41. Ferrimagnetic order in thin-film Fe3O4 studied by resonant inelastic X-ray scattering

Author

Hague, C F, Journel, L, Magnuson, Martin, Mariot, J-M, Sacchi, M, Gautier-Soyer, M, and Gota, S

Subjects
Naturvetenskap, Natural Sciences
Abstract

We have set out to use the ID21 microfocusing beamline to perform resonant inelastic x-ray scattering (RIXS) experiments on magnetic materials. For the first tests and experiments we start off with Fe oxide thin films of potential interest in new technical applications. Of main interest are thin films of Fe3O4 epitaxially grown on alumina. Note that RIXS is particularly well adapted to experiments involving samples on insulating substrates (no charging effects) prepared ex-situ (bulk sensitivity) which can be magnetized (all-photons experiment)....

Published
2000

42. Bulk electronic structure of Mn5Ge3/Ge(111) films by angle-resolved photoemission spectroscopy

Author

Ndiaye, W., primary, Richter, M. C., additional, Heckmann, O., additional, De Padova, P., additional, Mariot, J.-M., additional, Stroppa, A., additional, Picozzi, S., additional, Wang, W., additional, Taleb-Ibrahimi, A., additional, Le Fèvre, P., additional, Bertran, F., additional, Cacho, C., additional, Leandersson, M., additional, Balasubramanian, T., additional, and Hricovini, K., additional

Published
2013
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43. Fet2gband dispersion and spin polarization in thin films of Fe3O4(0 0 1)/MgO(0 0 1): Half-metallicity of magnetite revisited

Author

Wang, W., primary, Mariot, J.-M., additional, Richter, M. C., additional, Heckmann, O., additional, Ndiaye, W., additional, De Padova, P., additional, Taleb-Ibrahimi, A., additional, Le Fèvre, P., additional, Bertran, F., additional, Bondino, F., additional, Magnano, E., additional, Krempaský, J., additional, Blaha, P., additional, Cacho, C., additional, Parmigiani, F., additional, and Hricovini, K., additional

Published
2013
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45. Structural and chemical transformations induced by laser impact on TiO2 and Nb2O5

Author

Goubard, Fabrice, Dauzon, Emilie, Mansour, Ahmed, Niazi, Muhammad, Munir, Rahim, Smilgies, Detlef-M., Sallenave, Xavier, Plesse, Cedric, Amassian, Aram, Yuan, Xiaojiao, Floresyona, Dita, Aubert, Pierre-Henri, Bui, Thanh-Tuân, Remita, Samy, Ghosh, Srabanti, Brisset, François, Remita, Hynd, Le Mercier, T., Mariot, J.-M., Quarton, M., Fontaine, M.-F., Hague, C.F., Laboratoire de Physico-chimie des Polymères et des Interfaces (LPPI), Fédération INSTITUT DES MATÉRIAUX DE CERGY-PONTOISE (I-MAT), Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine, and CY Cergy Paris Université (CY)-CY Cergy Paris Université (CY)

Subjects
Valence (chemistry), Chemistry, [CHIM.ORGA]Chemical Sciences/Organic chemistry, Analytical chemistry, 02 engineering and technology, General Chemistry, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, 0104 chemical sciences, Ion, Paramagnetism, [CHIM.POLY]Chemical Sciences/Polymers, X-ray photoelectron spectroscopy, Rutile, Electrical resistivity and conductivity, General Materials Science, Irradiation, Diffuse reflection, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS
Abstract

TiO2 (rutile) and Nb2O5 have been irradiated by a 335 nm laser light. This changes the colour of these oxides from white to dark blue. The structural and chemical transformations induced by the irradiation have been investigated. Although no severe structural perturbation of the oxides is detected by X-ray diffraction, their electrical resistivity drops from ≈ 109Ω cm to ≈ 10 Ω cm in the case of TiO2 and to ≈ 10−2 Ω cm in the case of Nb2O5. The temperature dependence of the electrical transport properties can be explained by the formation under light irradiation of ions with unusual valence (Ti3+ and Ti2+, or Nb4+ and Nb2+), leading to energy levels in the electronic gap and to a hopping-driven conduction at room temperature. The presence of such ions is supported by diffuse reflectance, electronic paramagnetic resonance, and X-ray photoelectron spectroscopy measurements. Comparing with experimental data for these and related materials indicates that the defects associated with the presence of these ions could have the form of shear planes similar to those met in the Magneli phases TinO2n − 1 with n > 15.

Published
1997

46. Ferromagnetic Mn-doped Si0.3Ge0.7nanodots self-assembled on Si(100)

Author

De Padova, P, primary, Olivieri, B, additional, Mariot, J-M, additional, Favre, L, additional, Berbezier, I, additional, Quaresima, C, additional, Paci, B, additional, Generosi, A, additional, Rossi Albertini, V, additional, Cricenti, A, additional, Ottaviani, C, additional, Luce, M, additional, Testa, A M, additional, Peddis, D, additional, Fiorani, D, additional, Scarselli, M, additional, De Crescenzi, M, additional, Heckmann, O, additional, Richter, M C, additional, Hricovini, K, additional, and d’Acapito, F, additional

Published
2012
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47. Mn5Ge3 films grown on Ge(1 1 1)-c(2×8)

Author

De Padova, P., primary, Mariot, J.-M., additional, Favre, L., additional, Berbezier, I., additional, Olivieri, B., additional, Perfetti, P., additional, Quaresima, C., additional, Ottaviani, C., additional, Taleb-Ibrahimi, A., additional, Le Fèvre, P., additional, Bertran, F., additional, Heckmann, O., additional, Richter, M.C., additional, Ndiaye, W., additional, D'Orazio, F., additional, Lucari, F., additional, Cacho, C.M., additional, and Hricovini, K., additional

Published
2011
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48. Observation of magnetic circular dichroism in Fe L_{2,3} x-ray-fluorescence spectra

Author

Hague, C. F., Mariot, J-M, Strange, Paul, Durham, P. J., and Gyorffy, Balazs L.

Subjects
11000/12
Abstract

We report experiments demonstrating circular dichroism in the x-ray-fluorescence spectra of magnetic systems, as predicted by a recent theory. The data, on the L_{2,3} edges of ferromagnetic iron, are compared with fully relativistic local spin density functional calculations, and the relationship between the dichroic spectra and the spin-resolved local density of occupied states is discussed.

Published
1993

49. Magnetic Circular Dichroism in X-Ray Fluorescence

Author

Laurent Duda, Hague, C. F., Mancini, D. C., Mariot, J. -M, Marliere, C., Nordgren, J., Skytt, P., and Wassdahl, N.

Subjects
Astrophysics::High Energy Astrophysical Phenomena
Abstract

X-ray fluorescence spectra from magnetized iron excited by circularly polarized synchrotron radiation are reported. The Fe L2.3 emission band gives rise to a distinct dichroic signal in confirmation of a recent theoretical prediction. These preliminary experiments carried out with “white” and only partially circularly-polarized synchrotron radiation nevertheless reveal an asymmetry which reflects the spin polarization of the Fe 3d valence electrons. The usefulness of developing specialized high flux circularly-polarized sources is clearly established.

Published
1993

50. $\mbox{\sffamily\bfseries NiFe}_{\hbox{\sffamily\bfseries\fontsize{12}{12}\selectfont 2}}\mbox{\sffamily\bfseries O}_{\hbox{\sffamily\bfseries\fontsize{12}{12}\selectfont 4}}$ and $\mbox{\sffamily\bfseries Fe}_{\hbox{\sffamily\bfseries\fontsize{12}{12}\selectfont 3}}\mbox{\sffamily\bfseries O}_{\hbox{\sffamily\bfseries\fontsize{12}{12}\selectfont 4}}$ studied by XMCD and resonant photoemission

Author

Richter, M. C., primary, Mariot, J.-M., additional, Heckmann, O., additional, Kjeldgaard, L., additional, Mun, B. S., additional, Fadley, C. S., additional, Lüders, U., additional, Bobo, J.-F., additional, De Padova, P., additional, Taleb-Ibrahimi, A., additional, and Hricovini, K., additional

Published
2009
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