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1. In situ X-ray diffraction study of a TiO2 nanopowder Spark Plasma Sintering under very high pressure

Author

Sandrine Cottrino, Thomas Gaudisson, Stéphane Pailhès, Emanuela Archina Ferrara, Shashank Mishra, Stéphane Daniele, Mohamed Mézouar, Alain Largeteau, Yann Le Godec, Sylvie Le Floch, Matériaux, ingénierie et science [Villeurbanne] (MATEIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Institut Lumière Matière [Villeurbanne] (ILM), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Transport, Nanomagnétisme et Matériaux pour l'Énergie (ENERGIE), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), IRCELYON-C'Durable (CDURABLE), Institut de recherches sur la catalyse et l'environnement de Lyon (IRCELYON), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), École Supérieure de Chimie Physique Électronique de Lyon (CPE), European Synchroton Radiation Facility [Grenoble] (ESRF), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Programme de prématuration du CNRS

Subjects
In situ X-ray diffraction, Materials Chemistry, Ceramics and Composites, Activation energy, Nanopowder TiO2, [CHIM.MATE]Chemical Sciences/Material chemistry, High-pressure spark plasma sintering, Grain growth
Abstract

International audience; We investigated the effect of very high pressure on the sintering temperature, phase transition and the grain growth during Spark Plasma Sintering (SPS) of a 15 nm TiO2 nanopowder. Using in situ synchrotron X-ray diffraction during sintering at 1.5 and 3.5 GPa, we followed the evolution of the crystalline phases and the crystallite size as a function of temperature. In comparison, in the laboratory, SPS experiments were performed on two original facilities: A Paris-Edinburgh press and a high-pressure module adapted to standard SPS equipment. We studied the effect of the pressure on the sintering in the range 76 MPa to 3.5 GPa. We have shown that highly dense nanostructured ceramics can be prepared under very high pressure at low sintering temperatures. At 1 GPa, we limited the grain growth to an average size of 233 nm by heating at only 560 °C, and achieved a relative density of 98 %.

Published
2023
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2. Isostructural phase transition by point defect reorganization in the binary type-I clathrate Ba7.5Si45

Author

Holger Euchner, Vittoria Pischedda, Denis Machon, Alfonso San-Miguel, Patrice Mélinon, Stéphane Pailhès, Michael Hanfland, Régis Debord, (nano)Matériaux pour l'énergie (ENERGIE), Institut Lumière Matière [Villeurbanne] (ILM), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Helmholtz Institute Ulm (HIU), European Synchrotron Radiation Facility (ESRF), Spectroscopies optiques des matériaux verres, amorphes et à nanoparticules (SOPRANO), Laboratoire Nanotechnologies et Nanosystèmes [Sherbrooke] (LN2), Université de Sherbrooke (UdeS)-École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut Interdisciplinaire d'Innovation Technologique [Sherbrooke] (3IT), Université de Sherbrooke (UdeS), and Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)

Subjects
010302 applied physics, Diffraction, Phase transition, Isostructural phase transitions, Materials science, Polymers and Plastics, Metals and Alloys, Ab initio, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Crystallographic defect, Landau theory, Electronic, Optical and Magnetic Materials, Condensed Matter::Materials Science, Chemical physics, Vacancy defect, 0103 physical sciences, Ceramics and Composites, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Structural complexity, Isostructural, 0210 nano-technology, Single crystal
Abstract

International audience; Competition between microscopic point defect (vacancy and interstitial) configurations is inherent to crystalline phases of increased structural complexity. Phase transitions that preserve symmetry between them belong to a specific class of isostructural transitions. Type-I silicon clathrates are representatives of such structurally complex crystalline phases showing an intriguing structural transition at high pressure associated with an abrupt reduction of volume with no indication for any breakage of symmetry. Using isothermal high-pressure X-ray diffraction performed on a single crystal of the simplest representative type-I silicon clathrates, binary Ba 8 Si 46 , we confirm the isostructural character of the transition and identify the associated mechanism. A detailed analysis of the atomic structural parameters across the transition in combination with ab initio studies allow us to pinpoint a microscopic mechanism driven by a rearrangement of point defects initially present in the structure. An analysis based on the Landau theory gives a coherent description of the experimental observations. A discussion on the analogy between this transformation and liquid-liquid transitions is proposed.

Published
2021
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3. P-type thermoelectric LaCrO3-based epitaxial films grown by molecular beam epitaxy

Author

Dong Han, Esperonnat, Marc D., Mohamed Bouras, Rahma Moalla, Claude Botella, Aziz Benamrouche, Geneviève Grenet, Bruno Canut, Regis Debord, Giordano, Valentina M., Stéphane Pailhès, Guillaume Saint-Girons, Romain Bachelet, BACHELET, Romain, Institut des Nanotechnologies de Lyon (INL), Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-École Centrale de Lyon (ECL), Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE), (nano)Matériaux pour l'énergie (ENERGIE), Institut Lumière Matière [Villeurbanne] (ILM), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], ComputingMilieux_MISCELLANEOUS, [PHYS.COND.CM-MS] Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci]
Abstract

International audience

Published
2020

4. Lattice Dynamics Study of Thermoelectric Oxychalcogenide BiCuChO (Ch = Se, S)

Author

David Berardan, Jean-Louis Bantignies, David Maurin, Mickael Beaudhuin, Romain Viennois, Céline Barreteau, Michael Marek Koza, Nita Dragoe, Patrick Hermet, Stéphane Pailhès, M. T. Fernandez-Diaz, 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)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Charles Coulomb (L2C), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), (nano)Matériaux pour l'énergie (ENERGIE), Institut Lumière Matière [Villeurbanne] (ILM), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Institut Laue-Langevin (ILL), ILL, Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Université Paris-Sud - Paris 11 (UP11)-Institut de Chimie du CNRS (INC)-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), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon, and Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)

Subjects
Materials science, Condensed matter physics, Phonon, Anharmonicity, Neutron diffraction, 02 engineering and technology, Grüneisen parameter, 010402 general chemistry, 021001 nanoscience & nanotechnology, Thermoelectric materials, 7. Clean energy, 01 natural sciences, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Brillouin zone, Condensed Matter::Materials Science, General Energy, Thermal conductivity, Thermoelectric effect, [CHIM]Chemical Sciences, Physical and Theoretical Chemistry, 0210 nano-technology
Abstract

jp9b04806_si_001.pdf (1.0 MB); International audience; The BiCuSeO-based compounds with very low thermal conductivity are among the most promising thermoelectric materials recently discovered. Their lattice dynamics, which remains mostly unexplored experimentally, is investigated in this paper. We report Raman experiments on BiCuSe1–xSxO solid solutions and infrared experiments on BiCuSeO and BiCuSO alloys coupled to first-principles-based calculations. We have observed that the high-energy A1g Raman-active mode strongly depends on the chalcogen content. We also report the density functional theory calculations of the dielectric and elastic constants, the phonons in the whole Brillouin zone, and the thermodynamic properties. We have determined the thermal expansion of BiCuSeO at room temperature from neutron diffraction experiments and evaluated its thermodynamic Grüneisen parameter and found a quite large value compared to other thermoelectric materials, which confirms the large anharmonicity of BiCuSeO.

Published
2019
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5. Perovskite oxide engineering by molecular beam epitaxy for integrated thermoelectricity

Author

Mohamed Bouras, Mihai Apreutesei, Rahma Moalla, Debord, R., Philippe Regreny, Claude Botella, Geneviève Grenet, Matthieu Bugnet, Adrian Carretero-Genevrier, Jaume Gazquez, Acremont, Quentin D., Stefan Dilhaire, Chapuis, P. O., Stéphane Pailhès, Guillaume Saint-Girons, Romain Bachelet, INL - Hétéroepitaxie et Nanostructures (INL - H&N), Institut des Nanotechnologies de Lyon (INL), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Institut Lumière Matière [Villeurbanne] (ILM), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Matériaux, ingénierie et science [Villeurbanne] (MATEIS), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Institut d’Electronique et des Systèmes (IES), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Matériaux, MicroCapteurs et Acoustique (M2A), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Ondes et Matière d'Aquitaine (LOMA), Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS), Saint-Girons, Guillaume, Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-École Centrale de Lyon (ECL), Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], [PHYS.COND.CM-MS] Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2017

6. Thermal transport properties in amorphous/nanocrystalline metallic composites: A microscopic insight

Author

A. Assy, Nicholas Blanchard, Valentina M. Giordano, Jean-Jacques Blandin, Anne Tanguy, Beatrice Ruta, Stéphane Pailhès, S. Gomès, Sébastien Gravier, Régis Debord, Amani Tlili, Institut Lumière Matière [Villeurbanne] (ILM), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Science et Ingénierie des Matériaux et Procédés (SIMaP ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), European Synchrotron Radiation Facility (ESRF), Centre d'Energétique et de Thermique de Lyon (CETHIL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Mécanique des Contacts et des Structures [Villeurbanne] (LaMCoS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Milieux aquatiques, écologie et pollutions (UR MALY), and Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)

Subjects
Materials science, Polymers and Plastics, Phonon, 02 engineering and technology, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, Crystallinity, Condensed Matter::Materials Science, Electrical resistivity and conductivity, 0103 physical sciences, Composite material, 010306 general physics, Ductility, Composites, Amorphous metal, Scattering, Metals and Alloys, 021001 nanoscience & nanotechnology, Nanocrystalline material, Electronic, Optical and Magnetic Materials, Amorphous solid, Transport properties, Ceramics and Composites, Phonons, Bulk metallic glasses, 0210 nano-technology
Abstract

International audience; In the last years new composite materials made of a metallic glass matrix with embedded nanocrystals have arisen as a promising alternative to the metallic glasses, due to their higher hardness. Although the effects of a partial nano-crystallization onto mechanical and magnetic properties have been widely investigated, nothing is known about thermal transport properties, interesting for recently proposed novel applications. Here we investigate how thermal transport is modified in presence of nanocrystalline inclusions in a Zr-based bulk metallic glass. By means of electric measurements and inelastic x ray scattering we are able to disentangle the effects of a partial nanocrystallization onto the two different contributions to heat transport, the electronic and the vibrational one. We show that no enhanced electrons or phonons scattering from the interfaces is observed, while the presence of crystalline nanoinclusions leads to an increase of both contributions, via an increased electric conductivity and transverse acoustic speed of sound. Surprisingly, while a gradual modification of the electric conductivity with the crystalline fraction is observed, even a low crystalline fraction is sufficient to modify elastic and vibrational properties. Our results indicate that low crystallinity composites are indeed promising alternative to both amorphous and crystalline alloys, thanks to their unique combination of high ductility, polycrystal-like vibrational properties and amorphous-like electric transport. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Published
2017
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7. Boosting the power factor with resonant states: A model study

Author

Ch. Adessi, Stéphane Pailhès, G. Bouzerar, S. Thébaud, Institut Lumière Matière [Villeurbanne] (ILM), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)

Subjects
FOS: Physical sciences, Tight-binding model, 02 engineering and technology, Power factor, Conductivity, 01 natural sciences, 7. Clean energy, symbols.namesake, [SPI]Engineering Sciences [physics], Seebeck coefficient, 0103 physical sciences, Thermoelectric effect, Electrical conductivity, [CHIM]Chemical Sciences, 010306 general physics, Physics, [PHYS]Physics [physics], Condensed Matter - Materials Science, Valence (chemistry), Condensed matter physics, Fermi level, Materials Science (cond-mat.mtrl-sci), Thermoelectric systems, 021001 nanoscience & nanotechnology, Thermoelectric materials, Thermal conduction, Doped semiconductors, Semiconductors, Thermopower, symbols, 0210 nano-technology
Abstract

A particularly promising pathway to enhance the efficiency of thermoelectric materials lies in the use of resonant states, as suggested by experimentalists and theorists alike. In this paper, we go over the mechanisms used in the literature to explain how resonant levels affect the thermoelectric properties, and we suggest that the effects of hybridization are crucial yet ill-understood. In order to get a good grasp of the physical picture and to draw guidelines for thermoelectric enhancement, we use a tight-binding model containing a conduction band hybridized with a flat band. We find that the conductivity is suppressed in a wide energy range near the resonance, but that the Seebeck coefficient can be boosted for strong enough hybridization, thus allowing for a significant increase of the power factor. The Seebeck coefficient can also display a sign change as the Fermi level crosses the resonance. Our results suggest that in order to boost the power factor, the hybridization strength must not be too low, the resonant level must not be too close to the conduction (or valence) band edge, and the Fermi level must be located around, but not inside, the resonant peak., Comment: Accepted for publication in Physical Review B

Published
2017
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8. Unified modeling of the thermoelectric properties in SrTiO3

Author

S. Thébaud, Georges Bouzerar, Régis Debord, Stéphane Pailhès, Romain Bachelet, Ch. Adessi, M. Apreutesei, Institut Lumière Matière [Villeurbanne] (ILM), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon, INL - Hétéroepitaxie et Nanostructures (INL - H&N), Institut des Nanotechnologies de Lyon (INL), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), and Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, FOS: Physical sciences, General Physics and Astronomy, 02 engineering and technology, 01 natural sciences, 7. Clean energy, [SPI.MAT]Engineering Sciences [physics]/Materials, Tight binding, 0103 physical sciences, Thermoelectric effect, Energy transformation, Thin film, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, 010306 general physics, [PHYS]Physics [physics], Condensed Matter - Materials Science, [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Dopant, Scattering, Doping, Materials Science (cond-mat.mtrl-sci), 021001 nanoscience & nanotechnology, Thermoelectric materials, Engineering physics, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, 0210 nano-technology
Abstract

Thermoelectric materials are opening a promising pathway to address energy conversion issues governed by a competition between thermal and electronic transport. Improving the efficiency is a difficult task, a challenge that requires new strategies to unearth optimized compounds. We present a theory of thermoelectric transport in electron doped SrTiO3, based on a realistic tight binding model that includes relevant scattering processes. We compare our calculations against a wide panel of experimental data, both bulk and thin films. We find a qualitative and quantitative agreement over both a wide range of temperatures and carrier concentrations, from light to heavily doped. Moreover, the results appear insensitive to the nature of the dopant La, B, Gd and Nb. Thus, the quantitative success found in the case of SrTiO3, reveals an efficient procedure to explore new routes to improve the thermoelectric properties in oxides., 5 figures, manuscript submitted

Published
2017
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9. Prediction and Synthesis of a Non-Zintl Silicon Clathrate

Author

Romain Viennois, Régis Debord, Miguel A. L. Marques, Valentina M. Giordano, Jingming Shi, Tiago F. T. Cerqueira, Stéphane Pailhès, Silvana Botti, Institut Lumière Matière [Villeurbanne] (ILM), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS]Physics [physics], Silicon, Chemistry, General Chemical Engineering, Doping, Clathrate hydrate, chemistry.chemical_element, Nanotechnology, 02 engineering and technology, General Chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, [SPI]Engineering Sciences [physics], Chemical physics, 0103 physical sciences, Materials Chemistry, [CHIM]Chemical Sciences, Chemical stability, Wyckoff positions, 010306 general physics, 0210 nano-technology, Ternary operation, ComputingMilieux_MISCELLANEOUS
Abstract

We use computational high-throughput techniques to study the thermodynamic stability of ternary type I Si clathrates. Two strategies to stabilize the structures are investigated: through endohedral doping of the 2a and 6d Wyckoff positions (located at the center of the small and large cages, respectively) and by substituting the Si 6c positions. Our results agree with the overwhelming majority of experimental results and predict a series of unknown clathrate phases. Many of the stable phases can be explained by the simple Zintl–Klemm rule, but some are unexpected. We then successfully synthesize one of the latter compounds, a new type I silicon clathrate containing Ba (inside the cages) and Be (in the 6c position). These results prove the predictive power and reliability of our strategy and motivate the use of high-throughput screening of materials properties for the accelerated discovery of new clathrate phases.

Published
2016
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10. Observation of various magnetic-field-induced states in B20 cubic MnGe

Author

Stéphane Pailhès, Romain Viennois, Didier Ravot, Régis Debord, Corine Reibel, 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), Institut Lumière Matière [Villeurbanne] (ILM), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Condensed matter physics, Skyrmion, Magnetic signature, General Physics and Astronomy, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Magnetic susceptibility, Isothermal process, 3. Good health, Magnetic field, Phase (matter), 0103 physical sciences, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Crystallite, Isostructural, 010306 general physics, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS
Abstract

We report on the magnetic properties of the B20 polycrystalline MnGe compound synthesized under high-temperature and high-pressure conditions. From isothermal ac susceptibility experiments, we found the presence of several different magnetic-field–induced phases presenting similarities with those in the isostructural compounds MnSi and FeGe but with much broader existence range in the domain. From anomalies found in the ac magnetic susceptibility, we found not only the presence of an A phase similar to the one observed in MnSi but also a second phase we call B, whose magnetic signature is very similar to that of the A phase. Our discovery indicates that MnGe is a promising compound in order to further explore the existence conditions of the phases containing skyrmions.

Published
2015
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11. From crystal to glass-like thermal conductivity in crystalline minerals

Author

Janusz Tobola, Y. Bouyrie, Christophe Candolfi, Michael Marek Koza, Bernard Malaman, Bertrand Lenoir, Stéphane Pailhès, O. Boisron, Lucien Saviot, Anne Dauscher, Institut Jean Lamour ( IJL ), Université de Lorraine ( UL ) -Centre National de la Recherche Scientifique ( CNRS ), Institut Lumière Matière [Villeurbanne] ( ILM ), Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique ( CNRS ), Institut Laue-Langevin ( ILL ), ILL, Faculty of Physics and Applied Computer Science ( AGH ), University of Poland, Laboratoire Interdisciplinaire Carnot de Bourgogne ( LICB ), Université de Bourgogne ( UB ) -Centre National de la Recherche Scientifique ( CNRS ), Institut Jean Lamour (IJL), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Institut Lumière Matière [Villeurbanne] (ILM), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Institut Laue-Langevin (ILL), Faculty of Physics and Applied Computer Science (AGH), AGH University of Science and Technology [Krakow, PL] (AGH UST), Laboratoire Interdisciplinaire Carnot de Bourgogne (LICB), and Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, [ PHYS.COND.CM-MS ] Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], General Physics and Astronomy, Mineralogy, [ CHIM.INOR ] Chemical Sciences/Inorganic chemistry, Crystal structure, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, Thermal conduction, Thermoelectric materials, Inelastic neutron scattering, Amorphous solid, Crystal, Thermal conductivity, Chemical physics, Condensed Matter::Superconductivity, Thermoelectric effect, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Physical and Theoretical Chemistry
Abstract

Équipe 103 : Composés intermétalliques et matériaux hybrides; International audience; The ability of some materials with a perfectly ordered crystal structure to mimic the heat conduction of amorphous solids is a remarkable physical property that finds applications in numerous areas of materials science, for example, in the search for more efficient thermoelectric materials that enable to directly convert heat into electricity. Here, we unveil the mechanism in which glass-like thermal conductivity emerges in tetrahedrites, a family of natural minerals extensively studied in geology and, more recently, in thermoelectricity. By investigating the lattice dynamics of two tetrahedrites of very close compositions (Cu12Sb2Te2S13 and Cu10Te4S13) but with opposite glasslike and crystal thermal transport by means of powder and single-crystal inelastic neutron scattering, we demonstrate that the former originates from the peculiar chemical environment of the copper atoms giving rise to a strongly anharmonic excess of vibrational states.

Published
2015
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12. Epitaxial La-doped SrTiO3-based films of enhanced ZT

Author

Mihai Apreutesei, Regreny, P., Saint-Girons, G., Botella, C., Grenet, G., Carretero-Genevrier, A., Gazquez, J., Pierre-Olivier Chapuis, Régis Debord, Stéphane Pailhès, Romain Bachelet, CETHIL, Laboratoire, Matériaux, ingénierie et science [Villeurbanne] (MATEIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), INL - Hétéroepitaxie et Nanostructures (INL - H&N), Institut des Nanotechnologies de Lyon (INL), Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-École Centrale de Lyon (ECL), Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE), Centre d'Energétique et de Thermique de Lyon (CETHIL), Institut Lumière Matière [Villeurbanne] (ILM), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SPI.MECA.THER]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Thermics [physics.class-ph], ComputingMilieux_MISCELLANEOUS, [SPI.MECA.THER] Engineering Sciences [physics]/Mechanics [physics.med-ph]/Thermics [physics.class-ph]
Abstract

National audience

Published
2015

13. Anisotropic breakdown of Fermi liquid quasiparticle excitations in overdoped La2−xSrxCuO4

Author

Joël Mesot, Stéphane Pailhès, Oscar Tjernberg, Johan Juul Chang, Thomas Claesson, L. Patthey, O. J. Lipscombe, Martin Månsson, Stephen M Hayden, Ecole Polytechnique Fédérale de Lausanne (EPFL), The Swiss Light Source (SLS) (SLS-PSI), Paul Scherrer Institute (PSI), Laboratory for Neutron Scattering and Imaging [Paul Scherrer Institute] (LNS), Royal Institute of Technology [Stockholm] (KTH ), Institut Lumière Matière [Villeurbanne] (ILM), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), H. H. Wills Physics Laboratory [Bristol], University of Bristol [Bristol], Laboratory for Solid State Physics [ETH Zürich], Department of Physics [ETH Zürich] (D-PHYS), and Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)

Subjects
High-temperature superconductivity, General Physics and Astronomy, 02 engineering and technology, 01 natural sciences, General Biochemistry, Genetics and Molecular Biology, law.invention, [SPI]Engineering Sciences [physics], law, Quantum critical point, Condensed Matter::Superconductivity, 0103 physical sciences, [CHIM]Chemical Sciences, 010306 general physics, Physics, [PHYS]Physics [physics], Multidisciplinary, Condensed matter physics, Quantum oscillations, Fermi energy, Fermi surface, General Chemistry, 021001 nanoscience & nanotechnology, Quasiparticle, Condensed Matter::Strongly Correlated Electrons, Fermi liquid theory, 0210 nano-technology, Fermi gas
Abstract

International audience; High-temperature superconductivity emerges from an un-conventional metallic state. This has stimulated strong efforts to understand exactly how Fermi liquids breakdown and evolve into an un-conventional metal. A fundamental question is how Fermi liquid quasiparticle excitations break down in momentum space. Here we show, using angle-resolved photoemission spectroscopy, that the Fermi liquid quasiparticle excitations of the overdoped superconducting cuprate La1.77Sr0.23CuO4 is highly anisotropic in momentum space. The quasiparticle scattering and residue behave differently along the Fermi surface and hence the Kadowaki–Wood's relation is not obeyed. This kind of Fermi liquid breakdown may apply to a wide range of strongly correlated metal systems where spin fluctuations are present.

Published
2013
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14. Electronic structure and two-dimensional electron gas at the surface of SrTiO3

Author

Santander-Syro, A. F., Copie, O., Kondo, T., Fortuna, F., Stéphane Pailhès, Weht, R., Qiu, X. G., Bertran, F., Nicolaou, A., Taleb-Ibrahimi, A., Le Fèvre, P., Herranz, G., Bibes, M., Reyren, N., Apertet, Y., Lecoeur, P., Alain Barthélémy, Rozenberg, M. J., CSNSM PS2, Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)-Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), 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, Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Institut de Ciencia de materials de barcelone, Unité mixte de physique CNRS/Thales (UMPhy CNRS/THALES), Centre National de la Recherche Scientifique (CNRS)-THALES, Institut d'électronique fondamentale (IEF), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique des Solides (LPS), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11), Hadrossek, Christine, Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and THALES [France]-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], [PHYS.COND.CM-MS] Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci]
Published
2012

15. Absence of ferromagnetism in Mn-doped tetragonal zirconia

Author

S. K. Srivastava, Georges Bouzerar, O. Boisron, Pascal Lejay, Bernard Barbara, Stéphane Pailhès, Magnétisme et Supraconductivité (NEEL - MagSup), 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), Croissance Cristalline et MicroAnalyse (NEEL - C2MA), Circuits électroniques quantiques Alpes (NEEL - QuantECA), Laboratoire de Physique de la Matière Condensée et Nanostructures (LPMCN), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-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), Théorie de la Matière Condensée (NEEL - TMC), Jacobs University [Bremen], Magnétisme et Supraconductivité (MagSup), Cristaux Massifs (CrisMass), Circuits électroniques quantiques Alpes (QuantECA), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, and Théorie de la Matière Condensée (TMC)

Subjects
010302 applied physics, Condensed Matter - Materials Science, Materials science, Spintronics, Photoemission spectroscopy, General Physics and Astronomy, Materials Science (cond-mat.mtrl-sci), FOS: Physical sciences, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Magnetization, Paramagnetism, Crystallography, Tetragonal crystal system, Ferromagnetism, Ferrimagnetism, 0103 physical sciences, Antiferromagnetism, [PHYS.COND.CM-SCE]Physics [physics]/Condensed Matter [cond-mat]/Strongly Correlated Electrons [cond-mat.str-el], 0210 nano-technology
Abstract

In a recent letter, it has been predicted within first principle studies that Mn-doped ZrO2 compounds could be good candidate for spintronics application because expected to exhibit ferromagnetism far beyond room temperature. Our purpose is to address this issue experimentally for Mn-doped tetragonal zirconia. We have prepared polycrystalline samples of Y0.15(Zr0.85-yMny)O2 (y=0, 0.05, 0.10, 0.15 & 0.20) by using standard solid state method at equilibrium. The obtained samples were carefully characterized by using x-ray diffraction, scanning electron microscopy, elemental color mapping, X-ray photoemission spectroscopy and magnetization measurements. From the detailed structural analyses, we have observed that the 5% Mn doped compound crystallized into two symmetries (dominating tetragonal & monoclinic), whereas higher Mn doped compounds are found to be in the tetragonal symmetry only. The spectral splitting of the Mn 3s core-level x-ray photoelectron spectra confirms that Mn ions are in the Mn3+ oxidation state and indicate a local magnetic moment of about 4.5 ��B/Mn. Magnetic measurements showed that compounds up to 10% of Mn doping are paramagnetic with antiferromagnetic interactions. However, higher Mn doped compound exhibits local ferrimagnetic ordering. Thus, no ferromagnetism has been observed for all Mn-doped tetragonal ZrO2 samples., 20 pages, 4 figures

Published
2011
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16. Non-magnetic impurity induced magnetism in rutile TiO2:K compounds

Author

S. K. Srivastava, O. Boisron, Bernard Barbara, Georges Bouzerar, Pascal Lejay, Stéphane Pailhès, Cristaux Massifs (CrisMass), 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), Circuits électroniques quantiques Alpes (QuantECA), Laboratoire de Physique de la Matière Condensée et Nanostructures (LPMCN), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon, 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, Théorie de la Matière Condensée (TMC), Croissance Cristalline et MicroAnalyse (NEEL - C2MA), Circuits électroniques quantiques Alpes (NEEL - QuantECA), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Théorie de la Matière Condensée (NEEL - TMC)

Subjects
Condensed matter physics, Magnetic moment, Chemistry, Magnetism, Ab initio, 02 engineering and technology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Magnetic hysteresis, 01 natural sciences, Magnetic susceptibility, Paramagnetism, Condensed Matter::Materials Science, Ferromagnetism, Ab initio quantum chemistry methods, 0103 physical sciences, General Materials Science, [PHYS.COND.CM-SCE]Physics [physics]/Condensed Matter [cond-mat]/Strongly Correlated Electrons [cond-mat.str-el], 010306 general physics, 0210 nano-technology
Abstract

Recent ab initio studies have theoretically predicted room temperature ferromagnetism in several oxide materials of the type AO(2) in which the cation A(4+) is substituted by a non-magnetic element of the 1 A column. Our purpose is to address experimentally the possibility of magnetism in Ti(1-x)K(x)O(2) compounds. The samples have been synthesized via the solid state route method at equilibrium. Our study has shown that Ti(1-x)K(x)O(2) is thermodynamically unstable and leads to a phase separation, in contradiction with the hypothesis of ab initio calculations. In particular, the crystalline TiO(2) grains appear to be surrounded by K-based phase. The oxidization state of the Ti ion is found to be in Ti(4+) as confirmed from the x-ray photoelectron spectra measurement. Nevertheless, K:TiO(2) compounds exhibit weak paramagnetism with the highest magnetic moment of ~0.5 μ(B) K(-1) but no long-range ferromagnetic order. The observed moment in these compounds remains much smaller than the predicted moment of 3 μ(B) by ab initio calculation. The apparent contradictions between our experiments and first-principles studies are discussed.

Published
2011
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17. Two-dimensional geometry of spin excitations in the high-transition-temperature superconductor YBa2Cu3O6+x

Author

Bernhard Keimer, P. Bourges, Yvan Sidis, Chengtian Lin, Alexandre Ivanov, Christian Bernhard, Stéphane Pailhès, A. Kulakov, Vladimir Hinkov, D. P. Chen, LLB - Nouvelles frontières dans les matériaux quantiques (NFMQ), Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

Subjects
Copper oxide, FOS: Physical sciences, Geometry, 02 engineering and technology, Neutron scattering, 01 natural sciences, Superconductivity (cond-mat.supr-con), chemistry.chemical_compound, Condensed Matter - Strongly Correlated Electrons, Lattice (order), Condensed Matter::Superconductivity, 0103 physical sciences, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 010306 general physics, ComputingMilieux_MISCELLANEOUS, Superconductivity, Physics, Multidisciplinary, Condensed matter physics, Strongly Correlated Electrons (cond-mat.str-el), Transition temperature, Condensed Matter - Superconductivity, Doping, 021001 nanoscience & nanotechnology, [PHYS.COND.CM-S]Physics [physics]/Condensed Matter [cond-mat]/Superconductivity [cond-mat.supr-con], chemistry, Neutron diffusion, [PHYS.COND.CM-SCE]Physics [physics]/Condensed Matter [cond-mat]/Strongly Correlated Electrons [cond-mat.str-el], 0210 nano-technology
Abstract

The fundamental building block of the copper oxide superconductors is a Cu4O4 square plaquette. The plaquettes in most of these materials are slightly distorted to form a rectangular lattice, for which an influential theory predicts that high-transition-temperature (high-Tc) superconductivity is nucleated in ‘stripes’ aligned along one of the axes1,2,3. This theory received strong support from experiments that indicated a one-dimensional character for the magnetic excitations in the high-Tc material YBa2Cu3O6.6 (ref. 4). Here we report neutron scattering data on ‘untwinned’ YBa2Cu3O6+x crystals, in which the orientation of the rectangular lattice is maintained throughout the entire volume. Contrary to the earlier claim4, we demonstrate that the geometry of the magnetic fluctuations is two-dimensional. Rigid stripe arrays therefore appear to be ruled out over a wide range of doping levels in YBa2Cu3O6+x, but the data may be consistent with liquid-crystalline stripe order5. The debate about stripes has therefore been reopened.

Published
2004
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18. Two resonant magnetic modes in an overdoped high-$\bf T_c$ superconductor

Author

P. Bourges, B. Liang, Bernhard Keimer, Vladimir Hinkov, Christian Bernhard, Clemens Ulrich, Alexandre Ivanov, Chengtian Lin, Stéphane Pailhès, L. P. Regnault, Yvan Sidis, 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), Service de Physique Statistique, Magnétisme et Supraconductivité (SPSMS - UMR 9001), Institut Nanosciences et Cryogénie (INAC), 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]), Institut Laue-Langevin (ILL), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, and ILL

Subjects
Physics, Superconductivity, Copper oxide, Condensed matter physics, Spectral weight, Strongly Correlated Electrons (cond-mat.str-el), Condensed Matter - Superconductivity, Doping, General Physics and Astronomy, FOS: Physical sciences, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Inelastic neutron scattering, Symmetry (physics), Superconductivity (cond-mat.supr-con), [PHYS.COND.CM-S]Physics [physics]/Condensed Matter [cond-mat]/Superconductivity [cond-mat.supr-con], chemistry.chemical_compound, Condensed Matter - Strongly Correlated Electrons, chemistry, Condensed Matter::Superconductivity, 0103 physical sciences, 010306 general physics, 0210 nano-technology
Abstract

A detailed inelastic neutron scattering study of the overdoped high temperature copper oxide superconductor ${Y_{0.9}Ca_{0.1}Ba_{2}Cu_3O_{7}}$ reveals two distinct magnetic resonant modes in the superconducting state. The modes differ in their symmetry with respect to exchange between adjacent copper oxide layers. Counterparts of the mode with odd symmetry, but not the one with even symmetry, had been observed before at lower doping levels. The observation of the even mode resolves a long-standing puzzle, and the spectral weight ratio of both modes yields an estimate of the onset of particle-hole spin-flip excitations., Comment: Submitted to PRL

Published
2003
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19. Génération d’architectures nanométriques intra- et inter-granulaires dans des oxydes pour la conversion thermoélectrique de l’énergie

Author

Verchère, Alexandre, Institut de recherches sur la catalyse et l'environnement de Lyon (IRCELYON), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Lyon, Stéphane Daniele, Shashank Mishra, and Stéphane Pailhès

Subjects
Molecular precursors, Spark plasma sintering, Oxydes nanostructurés, Conversion thermoélectrique de l'énergie, Procédé sol-gel, Transport thermique, Décomposition spinodale, Spinodal decomposition, Précurseurs moléculaires, Sol-gel process, [CHIM.OTHE]Chemical Sciences/Other, Thermoelectric conversion of energy, Nanostructured oxides, Thermal transport
Abstract

In this manuscript, a multidisciplinary work, from the synthesis of metal precursors to the characterization of materials, is presented. The first concerns the development of Nb5+ doped TiO2 oxide powders and Nb5+ doped SnO2-TiO2 mixed oxides by a Sol-Gel approach. Their shaping into a pellet form by a modern flash sintering method (SPS) made it possible to study their physical, vibrational and thermoelectric properties. The second part of this study presents the development of new tin and tantalum precursors adapted to the DLI-MOCVD thin film deposition process. In order to meet the requirements of this process, molecular derivatives based on fluorinated or non-fluorinated beta-aminoalcohol ligand have been developed. The metal complexes were then fully characterized in solid state and in solution. The good thermal behaviour (stability and volatility) of some of these compounds has led to the development and characterization of thin layers of SnO2 and SnO2:F; Dans ce manuscrit, un travail multidisciplinaire, de la synthèse de précurseurs métalliques à la caractérisation des matériaux est présenté. La première porte sur l’élaboration de poudres d’oxyde TiO2 dopé Nb5+ et d’oxydes mixtes SnO2-TiO2 dopé Nb5+ par une approche Sol-Gel. Leur mise en forme sous forme de pastille par une méthode moderne de frittage flash (SPS) a permis d’étudier leurs propriétés physiques vibrationnelles et thermoélectriques. La deuxième partie de cette étude présente l’élaboration de nouveaux précurseurs d’étain et de tantale adaptés au procédé de dépôt de couches minces par DLI-MOCVD. Afin de répondre aux exigences de ce procédé, des dérivés moléculaires à base de ligand beta-aminoalcool fluoré ou pas ont été élaborées. Les complexes métalliques ont ensuite été entièrement caractérisés à l’état solide et en solution. Le bon comportement thermique (stabilité et volatilité) de certains de ces composés ont conduit à l’élaboration et à la caractérisation de couches minces de SnO2 et SnO2:F

Published
2019

20. Generation of intra- and inter-granular nanometric architectures in oxides for the thermoelectric conversion of the energy

Author

Verchère, Alexandre, Institut de recherches sur la catalyse et l'environnement de Lyon (IRCELYON), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Lyon, Stéphane Daniele, Shashank Mishra, Stéphane Pailhès, and STAR, ABES

Subjects
Molecular precursors, Spark plasma sintering, Oxydes nanostructurés, Conversion thermoélectrique de l'énergie, Procédé sol-gel, Transport thermique, Décomposition spinodale, [CHIM.OTHE] Chemical Sciences/Other, Spinodal decomposition, Précurseurs moléculaires, Sol-gel process, [CHIM.OTHE]Chemical Sciences/Other, Thermoelectric conversion of energy, Nanostructured oxides, Thermal transport
Abstract

In this manuscript, a multidisciplinary work, from the synthesis of metal precursors to the characterization of materials, is presented. The first concerns the development of Nb5+ doped TiO2 oxide powders and Nb5+ doped SnO2-TiO2 mixed oxides by a Sol-Gel approach. Their shaping into a pellet form by a modern flash sintering method (SPS) made it possible to study their physical, vibrational and thermoelectric properties. The second part of this study presents the development of new tin and tantalum precursors adapted to the DLI-MOCVD thin film deposition process. In order to meet the requirements of this process, molecular derivatives based on fluorinated or non-fluorinated beta-aminoalcohol ligand have been developed. The metal complexes were then fully characterized in solid state and in solution. The good thermal behaviour (stability and volatility) of some of these compounds has led to the development and characterization of thin layers of SnO2 and SnO2:F, Dans ce manuscrit, un travail multidisciplinaire, de la synthèse de précurseurs métalliques à la caractérisation des matériaux est présenté. La première porte sur l’élaboration de poudres d’oxyde TiO2 dopé Nb5+ et d’oxydes mixtes SnO2-TiO2 dopé Nb5+ par une approche Sol-Gel. Leur mise en forme sous forme de pastille par une méthode moderne de frittage flash (SPS) a permis d’étudier leurs propriétés physiques vibrationnelles et thermoélectriques. La deuxième partie de cette étude présente l’élaboration de nouveaux précurseurs d’étain et de tantale adaptés au procédé de dépôt de couches minces par DLI-MOCVD. Afin de répondre aux exigences de ce procédé, des dérivés moléculaires à base de ligand beta-aminoalcool fluoré ou pas ont été élaborées. Les complexes métalliques ont ensuite été entièrement caractérisés à l’état solide et en solution. Le bon comportement thermique (stabilité et volatilité) de certains de ces composés ont conduit à l’élaboration et à la caractérisation de couches minces de SnO2 et SnO2:F

Published
2019

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