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1. Implementation strategies in phonopy and phono3py

Author

Togo, Atsushi, Chaput, Laurent, Tadano, Terumasa, and Tanaka, Isao

Subjects
Condensed Matter - Materials Science
Abstract

Scientific simulation codes are public property sustained by the community. Modern technology allows anyone to join scientific software projects, from anywhere, remotely via the internet. The phonopy and phono3py codes are widely used open source phonon calculation codes. This review describes a collection of computational methods and techniques as implemented in these codes and shows their implementation strategies as a whole, aiming to be useful for the community. Some of the techniques presented here are not limited to phonon calculations and may therefore be useful in other area of condensed matter physics.

Published
2023
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2. Zero-point Renormalization of the Band Gap of Semiconductors and Insulators Using the PAW Method

Author

Engel, Manuel, Miranda, Henrique, Chaput, Laurent, Togo, Atsushi, Verdi, Carla, Marsman, Martijn, and Kresse, Georg

Subjects
Condensed Matter - Materials Science
Abstract

We evaluate the zero-point renormalization (ZPR) due to electron-phonon interactions of 28 solids using the projector-augmented-wave (PAW) method. The calculations cover diamond, many zincblende semiconductors, rock-salt and wurtzite oxides, as well as silicate and titania. Particular care is taken to include long-range electrostatic interactions via a generalized Fr\"ohlich model, as discussed in Phys. Rev. Lett. 115, 176401 (2015) and Phys. Rev. B 92, 054307 (2015). The data are compared to recent calculations, npj Computational Materials 6, 167 (2020), and generally very good agreement is found. We discuss in detail the evaluation of the electron-phonon matrix elements within the PAW method. We show that two distinct versions can be obtained depending on when the atomic derivatives are taken. If the PAW transformation is applied before taking derivatives with respect to the ionic positions, equations similar to the ones conventionally used in pseudopotential codes are obtained. If the PAW transformation is used after taking the derivatives, the full-potential spirit is largely maintained. We show that both variants yield very similar ZPRs for selected materials when the rigid-ion approximation is employed. In practice, we find however that the pseudo version converges more rapidly with respect to the number of included unoccupied states., Comment: Added pseudopotential information; revised Sec. II B to avoid possible misconceptions; revised discussion in Sec. III A; added diamond calculation with harder pseudopotential; corrected ZPR comparisons for AlSb and GaP due to inconsistent band-gap transitions; conclusion unchanged

Published
2022
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3. Transferability of neural network potentials for varying stoichiometry: phonons and thermal conductivity of Mn$_x$Ge$_y$ compounds

Author

Mangold, Claudia, Chen, Shunda, Barbalinardo, Giuseppe, Behler, Joerg, Pochet, Pascal, Termentzidis, Konstantinos, Han, Yang, Chaput, Laurent, Lacroix, David, and Donadio, Davide

Subjects
Condensed Matter - Materials Science
Abstract

Germanium manganese compounds exhibit a variety of stable and metastable phases with different stoichiometry. These materials entail interesting electronic, magnetic and thermal properties both in their bulk form and as heterostructures. Here we develop and validate a transferable machine learning potential, based on the high-dimensional neural network formalism, to enable the study of Mn$_x$Ge$_y$ materials over a wide range of compositions. We show that a neural network potential fitted on a minimal training set reproduces successfully the structural and vibrational properties and the thermal conductivity of systems with different local chemical environments, and it can be used to predict phononic effects in nanoscale heterostructures., Comment: 29 pages, 9 figures

Published
2020
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6. Discovery of low thermal conductivity compounds with first-principles anharmonic lattice dynamics calculations and Bayesian optimization

Author

Seko, Atsuto, Togo, Atsushi, Hayashi, Hiroyuki, Tsuda, Koji, Chaput, Laurent, and Tanaka, Isao

Subjects
Condensed Matter - Materials Science
Abstract

Compounds of low lattice thermal conductivity (LTC) are essential for seeking thermoelectric materials with high conversion efficiency. Some strategies have been used to decrease LTC. However, such trials have yielded successes only within a limited exploration space. Here we report the virtual screening of a library containing 54,779 compounds. Our strategy is to search the library through Bayesian optimization using for the initial data the LTC obtained from first-principles anharmonic lattice dynamics calculations for a set of 101 compounds. We discovered 221 materials with very low LTC. Two of them have even an electronic band gap < 1 eV, what makes them exceptional candidates for thermoelectric applications. In addition to those newly discovered thermoelectric materials, the present strategy is believed to be powerful for many other applications in which chemistry of materials are required to be optimized., Comment: 6 pages, 4 figures

Published
2015
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7. Distribution of phonon lifetime in Brillouin zone

Author

Togo, Atsushi, Chaput, Laurent, and Tanaka, Isao

Subjects
Condensed Matter - Materials Science
Abstract

Lattice thermal conductivities of zincblende- and wurtzite-type compounds with 33 combinations of elements are calculated with the single-mode relaxation-time approximation and linearized phonon Boltzmann equation from first-principles anharmonic lattice dynamics calculations. In 9 zincblende-type compounds, distributions of phonon linewidths (inverse phonon lifetimes) are discussed in detail. The phonon linewidths vary non-smoothly with respect to wave vector, which is explained from the imaginary parts of the self energies. It is presented that detailed combination of phonon-phonon interaction strength and three phonon selection rule is critically important to determine phonon lifetime for these compounds. This indicates difficulty to predict phonon lifetime quantitatively without anharmonic force constants. However it is shown that joint density of states weighted by phonon numbers, which is calculated only from harmonic force constants, can be potentially used for a screening of the lattice thermal conductivity of materials.

Published
2015
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8. A direct solution to the phonon Boltzmann equation

Author

Chaput, Laurent

Subjects
Condensed Matter - Materials Science
Abstract

The frequency dependent phonon Boltzmann equation is transformed to an integral equation over the irreducible part of the Brillouin zone. Simultaneous diagonalization of the collision kernel of that equation and a symmetry crystal class operator allow to obtain a spectral representation of the lattice thermal conductivity valid at finite frequency. The method is applied to C, Si and Mg$_2$Si to obtain the static and dynamical thermal conductivities.

Published
2013

9. Neutron Diffraction Measurements and First Principles Study of Thermal Motion of Atoms in Select M_{n+1}AX_n and Binary MX Transition Metal Carbide Phases

Author

Lane, Nina J., Vogel, Sven C., Hug, Gilles, Togo, Atsushi, Chaput, Laurent, Hultman, Lars, and Barsoum, Michel W.

Subjects
Condensed Matter - Materials Science
Abstract

Herein, we compare the thermal vibrations of atoms in select ternary carbides with the formula Mn+1AXn ("MAX phases," M = Ti, Cr; A = Al, Si, Ge; X = C, N) as determined from first principles phonon calculations to those obtained from high-temperature neutron powder diffraction studies. The transition metal carbides TiC, TaC, and WC are also studied to test our methodology on simpler carbides. Good qualitative and quantitative agreement is found between predicted and experimental values for the binary carbides. For all the MAX phases studied - Ti3SiC2, Ti3GeC2, Ti2AlN, Cr2GeC and Ti4AlN3 - density functional theory calculations predict that the A element vibrates with the highest amplitude and does so anisotropically with a higher amplitude within the basal plane, which is in line with earlier results from high-temperature neutron diffraction studies. In some cases, there are quantitative differences in the absolute values between the theoretical and experimental atomic displacement parameters, such as reversal of anisotropy or a systematic offset of temperature-dependent atomic displacement parameters. The mode-dependent Gr\"uneisen parameters are also computed to explore the anharmonicity in the system.

Published
2012
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10. Giant thermoelectric effect in Al2O3 magnetic tunnel junctions

Author

Lin, Weiwei, Hehn, Michel, Chaput, Laurent, Negulescu, Béatrice, Andrieu, Stéphane, Montaigne, François, and Mangin, Stéphane

Subjects
Condensed Matter - Materials Science, Condensed Matter - Mesoscale and Nanoscale Physics, Physics - Applied Physics
Abstract

Thermoelectric effects in magnetic nanostructures and the so-called spin caloritronics are attracting much interest. Indeed it provides a new way to control and manipulate spin currents which are key elements of spin-based electronics. Here we report on giant magnetothermoelectric effect in Al2O3 magnetic tunnel junctions. The thermovoltage in this geometry can reach 1 mV. Moreover a magneto-thermovoltage effect could be measured with ratio similar to the tunnel magnetoresistance ratio. The Seebeck coefficient can then be tuned by changing the relative magnetization orientation of the two magnetic layers in the tunnel junction. Therefore our experiments extend the range of spintronic devices application to thermoelectricity and provide a crucial piece of information for understanding the physics of thermal spin transport., Comment: 9 pages, 7 figures, added references

Published
2011
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11. Phonon-phonon interactions in transition metals

Author

Chaput, Laurent, Togo, Atsushi, Tanaka, Isao, and Hug, Gilles

Subjects
Condensed Matter - Materials Science
Abstract

In this paper the phonon self energy produced by anharmonicity is calculated using second order many body perturbation theory for all bcc, fcc and hcp transition metals. The symmetry properties of the phonon interactions are used to obtain an expression for the self energy as a sum over irreducible triplets, very similar to integration in the irreducible part of the Brillouin zone for one particle properties. The results obtained for transition metals shows that the lifetime is on the order of 10^10 s. Moreover the Peierls approximation for the imaginary part of the self energy is shown to be reasonable for bcc and fcc metals. For hcp metals we show that the Raman active mode decays into a pair of acoustic phonons, their wave vector being located on a surface defined by conservation laws., Comment: 14 pages, 3 figures

Published
2011
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16. Monte Carlo and DFT Calculations Coupling; Application to Heat Transfer in Nanostructures

Author

Lacroix, David, Chaput, Laurent, Laboratoire Énergies et Mécanique Théorique et Appliquée (LEMTA ), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), and LACROIX, David

Subjects
[SPI.MECA.THER]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Thermics [physics.class-ph], [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], [PHYS.COND] Physics [physics]/Condensed Matter [cond-mat], ComputingMilieux_MISCELLANEOUS, [SPI.MECA.THER] Engineering Sciences [physics]/Mechanics [physics.med-ph]/Thermics [physics.class-ph]
Abstract

International audience

Published
2021

17. Poster: Electronic Structure, Lattice Dynamics, and Transport

Author

Richter, Christoph, primary, Boschker, Hans, additional, Dietsche, Werner, additional, Mannhart, Jochen, additional, Brasse, M., additional, Jany, R., additional, Heyn, Ch., additional, Mannhart, J., additional, Wilde, M. A., additional, Grundler, D., additional, Tada, Masahiro, additional, Miyauchi, Yohei, additional, Yoshiya, Masato, additional, Yasuda, Hideyuki, additional, Sagarna, Leyre, additional, Maegli, Alexandra, additional, Yoon, Songhak, additional, Populoh, Sascha, additional, Shkabko, Andrey, additional, Weidenkaff, Anke, additional, Karthäuser, Silvia, additional, Manheller, Marcel, additional, Waser, Rainer, additional, Blech, Kerstin, additional, Simon, Ulrich, additional, Pengpan, T., additional, Boonthummo, A., additional, Togo, Atsushi, additional, Chaput, Laurent, additional, Tanaka, Isao, additional, Ramírez, M. A, additional, Simões, A. Z, additional, Longo, E., additional, Varela, J. A, additional, Xu, Pengxiang, additional, Schena, Timo, additional, Bihlmayer, Gustav, additional, Blügel, Stefan, additional, Thatribud, A., additional, Tungsurat, T., additional, Tan, X. L., additional, Chen, P. F., additional, Wang, L. F., additional, Zhi, B. W., additional, Wu, W. B., additional, Nikolaev, A. V., additional, Michel, K. H., additional, Tsvyashchenko, A. V., additional, Velichkov, A. I., additional, Salamatin, A. V., additional, Fomicheva, L. N., additional, Ryasny, G. K., additional, Sorokin, A. A., additional, Kochetov, O. I., additional, Budzynski, M., additional, Prieto, P., additional, Gómez, M. E., additional, Puig, T., additional, Obradors, X., additional, Palau, A., additional, Llordés, A., additional, Coll, M., additional, Vlad, R., additional, Gazquez, J., additional, Arbiol, J., additional, Guzmán, R., additional, Pomar, A., additional, Sandiumenge, F., additional, Ricart, S., additional, Rouco, V., additional, Ye, S., additional, Deutscher, G., additional, Chataigner, D., additional, Varela, M., additional, Magen, C., additional, Vanacken, J., additional, Gutierrez, J., additional, Moshchalkov, V. V., additional, Broglia, Giulia, additional, Montorsi, Monia, additional, Larcher, Luca, additional, Padovani, Andrea, additional, Nasr Esfahani, D., additional, Covaci, L., additional, Peeters, F. M., additional, Ohnishi, Hiromasa, additional, Kosugi, Taichi, additional, Miyake, Takashi, additional, Ishibashi, Shoji, additional, Terakura, Kiyoyuki, additional, Medarde, Marisa, additional, Straessle, Thierry, additional, Pomjakushin, Vladimir, additional, Martínez-Lope, María Jesus, additional, Alonso, José Antonio, additional, Nowak, R., additional, Chrobak, D., additional, Gerberich, W. W., additional, Niihara, K., additional, Wyrobek, T., additional, Estradé, S., additional, Rebled, J. M., additional, Walls, M. G., additional, de la Peña, F., additional, Colliex, C., additional, Córdoba, R., additional, Infante, I. C., additional, Herranz, G., additional, Sánchez, F., additional, Fontcuberta, J., additional, Peiró, F., additional, Velessiotis, D., additional, Douvas, A. M., additional, Dimitrakis, P., additional, Argitis, P., additional, Glezos, N., additional, Chrobak, Dariusz, additional, Gerberich, William W., additional, Nowak, Roman, additional, Meyer, Carola, additional, Spudat, C., additional, Müller, M., additional, Houben, L., additional, Maultzsch, J., additional, Goss, K., additional, Thomsen, C., additional, Schneider, C. M., additional, Reza Golobostanfard, Mohammad, additional, Abdizadeh, Hossein, additional, Schmidt, Manuel J., additional, Engels, Stephan, additional, Epping, Alexander, additional, Trellenkamp, Stefan, additional, Wichmann, Uwe, additional, Stampfer, Christoph, additional, Rocha, Paulo R. F., additional, Chen, Qian, additional, Kiazadeh, Asal, additional, Gomes, Henrique L., additional, Meskers, Stefan, additional, de Leeuw, Dago, additional, Paßens, Michael, additional, Busiakiewicz, Adam, additional, Franz, Adam W., additional, Barkschat, Christa S., additional, Urselmann, Dominik, additional, Müller, Thomas J. J., additional, Soltow, A., additional, Karthäuser, S., additional, Waser, R., additional, Zeng, Fei, additional, Yang, Jing, additional, Wang, Zhishun, additional, Lin, Yisong, additional, Li, Sizhao, additional, Hirschfeld, Julian A., additional, and Lustfeld, Hans, additional

Published
2013
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19. Nanoscale heat transfer via Ab-Initio Monte Carlo simulation

Author

Davier, Brice, Larroque, Jérôme, Dollfus, Philippe, Chaput, Laurent, Volz, Sebastian, saint-martin, Jérôme, Centre de Nanosciences et Nanotechnologies (C2N (UMR_9001)), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), and saint-martin, Jérôme

Subjects
[SPI.NANO] Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, [SPI.TRON] Engineering Sciences [physics]/Electronics, ComputingMilieux_MISCELLANEOUS, [SPI.TRON]Engineering Sciences [physics]/Electronics
Abstract

International audience

Published
2019

20. Full Band Ab-Initio Monte Carlo simulation of heat transfer in nanostructures

Author

Davier, B., Larroque, J., Dollfus, Philippe, Chaput, Laurent, Volz, S., Lacroix, David, saint-martin, Jérôme, Centre de Nanosciences et de Nanotechnologies [Orsay] (C2N), Université Paris-Sud - Paris 11 (UP11)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut d'électronique fondamentale (IEF), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Énergies et Mécanique Théorique et Appliquée (LEMTA ), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Laboratory for Integrated Micro Mechatronics Systems (LIMMS), The University of Tokyo (UTokyo)-Centre National de la Recherche Scientifique (CNRS), and French National Research Agency (ANR) as part of the ‘Investissements d’Avenir’ program (Labex NanoSaclay, reference: ANR-10-LABX-0035).

Subjects
[PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph], [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, [SPI.TRON]Engineering Sciences [physics]/Electronics
Abstract

International audience; Modeling accurately the heat transfer in devices having a characteristic length close to the phonon mean free path in which the Fourier’s heat transport formalism reaches its limits is challenging [1]. Besides when the lateral size of the structure also reaches the nanoscale, the role of the phonon reflections at the external interfaces becomes of high importance. The Boltzmann’s transport equation for phonons (pBTE) can be used to investigate heat transport regimes beyond the diffusive regime in structures in the range of few nanometers to few microns. A stochastic resolution of the pBTE based on particle Monte Carlo (MC) algorithm is very efficient in terms of computational resources in the case of complex systems [2].In this work, an original versatile particle MC simulator in which the material parameters, i.e. phonon dispersion and scattering rates, are parametrized by using ab initio calculations is presented [3]. It is a Full-band simulator as both the dispersion and the scattering rates are computed in the entire 3D Brillouin zone. Besides, for modeling the transport at rough external interfaces, a combination of specular and diffuse phonon reflections at the external rough interfaces have been implemented in phase space. This coupling between MC and ab-initio methods overcomes the main limitation of the MC approach by allowing the study of a large set of phases and materials without any empirical parameter. Moreover, the thermal transport can be investigated along all transport directions. In this work the phonon transport in rough nanowires and thin films made of both cubic (Si3C) and hexagonal (Si2H) Silicon have been carefully investigated by using our MC approach. For instance, the effective thermal conductivity is plotted as a function of the length in Figure a). The transition from a ballistic regime in short devices to a diffusive regime in long devices is clearly illustrated. In Figure b) the angular distribution of the density of states (DOS) shows that the main direction of the thermal flux in Si3C is [100] but [111] and [110] are also significant. Finally, the contribution of each phonon band is detailed. References:[1] D.G. Cahill, et al., J. App. Phys. 93, 793 (2003) [2] D. Lacroix, et al., Appl. Phys. Lett. 89, 103104 (2006)[3] L. Chaput, et al., Appl. Phys. Lett. 112, 033104 (2018)

Published
2018

23. Tuning the thermal conductivity of Bi2Te3 one dimensional nanostructures: simulation and synthesis

Author

Stein, Nicolas, Termentzidis, Konstantinos, Danine, A, Li, Shen, Thiebaud, L., Chaput, Laurent, Legeai, Sophie, Boulanger, Clothilde, Lacroix, David, Institut Jean Lamour (IJL), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Énergies et Mécanique Théorique et Appliquée (LEMTA ), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), and LACROIX, David

Subjects
[PHYS.MECA.THER] Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph], [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], [PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph], [PHYS.COND.CM-MS] Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2016

24. Simple view of the Mg2Si1-xSnx phonon spectrum: Sn resonances and mean field

Author

Chaput, Laurent, Bourgeois, Julie, Prytuliak, Anastasiia, Koza, Michael Marek, Scherrer, Hubert, Institut Jean Lamour (IJL), Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Science des Matériaux de Mulhouse (IS2M), Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS), Laboratoire de cristallographie et sciences des matériaux (CRISMAT), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Agence Spatiale Européenne = European Space Agency (ESA), and Institut Laue-Langevin (ILL)

Subjects
[CHIM.INOR]Chemical Sciences/Inorganic chemistry, ComputingMilieux_MISCELLANEOUS
Abstract

International audience; We have studied the phonon spectrum of Mg2Si1−xSnx alloys using both density-functional theory calculations and neutron measurements. In the low tin concentration limit a resonance is obtained in the lower part of the spectrum. At higher concentrations comparison between theory and experiments shows that a simple averaging of the force constants of the perfect crystals Mg2Si and Mg2Sn can explain the main features of the density of states. However we suggest that the tin resonance persists up to large tin concentrations and may therefore be important for transport properties.

Published
2015

25. Nanomatériaux thermoélectriques

Author

Godart, Claude, Alleno, Eric, Boulanger, Clothilde, Chaput, Laurent, Chubilleau, Caroline, Dauscher, Anne, UL, IJL, NOËL Didier, Web Scale Trustworthy Collaborative Service Systems (COAST), Inria Nancy - Grand Est, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Department of Networks, Systems and Services (LORIA - NSS), Laboratoire Lorrain de Recherche en Informatique et ses Applications (LORIA), Institut National de Recherche en Informatique et en Automatique (Inria)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire Lorrain de Recherche en Informatique et ses Applications (LORIA), Institut National de Recherche en Informatique et en Automatique (Inria)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie et des Matériaux Paris-Est (ICMPE), Institut de Chimie du CNRS (INC)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Énergies et Mécanique Théorique et Appliquée (LEMTA ), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Institut Jean Lamour (IJL), and Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)

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

International audience

Published
2014

28. Prediction of Low-Thermal-Conductivity Compounds with First-Principles Anharmonic Lattice-Dynamics Calculations and Bayesian Optimization

Author

10452319, 70183861, Seko, Atsuto, Togo, Atsushi, Hayashi, Hiroyuki, Tsuda, Koji, Chaput, Laurent, Tanaka, Isao, 10452319, 70183861, Seko, Atsuto, Togo, Atsushi, Hayashi, Hiroyuki, Tsuda, Koji, Chaput, Laurent, and Tanaka, Isao

Abstract

Compounds of low lattice thermal conductivity (LTC) are essential for seeking thermoelectric materials with high conversion efficiency. Some strategies have been used to decrease LTC. However, such trials have yielded successes only within a limited exploration space. Here, we report the virtual screening of a library containing 54 779 compounds. Our strategy is to search the library through Bayesian optimization using for the initial data the LTC obtained from first-principles anharmonic lattice-dynamics calculations for a set of 101 compounds. We discovered 221 materials with very low LTC. Two of them even have an electronic band gap <1 eV, which makes them exceptional candidates for thermoelectric applications. In addition to those newly discovered thermoelectric materials, the present strategy is believed to be powerful for many other applications in which the chemistry of materials is required to be optimized.

Published
2015

29. The 2 root 3 x 2 root 3R30 surface reconstruction of alkali/Si(111):B semiconducting surfaces

Author

Tournier-Colletta, Cédric, Chaput, Laurent, Tejeda, Antonio, Cardenas, Luis A., Kierren, Bertrand, Malterre, Daniel, Fagot-Révurat, Yannick, Le Fèvre, P., Bertran, F., Taleb-Ibrahimi, A., Institut Jean Lamour (IJL), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), and Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
LEED, root 3-reconstructed semiconducting surfaces, XPS, STM, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], LAPW-DFT calculations, Alkalioverlayers
Abstract

Équipe 102 : Surfaces et Spectroscopies; International audience; The surface structure of alkali doped Si(111): B ultra-thin films has been studied by low-energy electron diffraction (LEED), X-ray photoemission spectroscopy (XPS) and scanning tunneling microscopy (STM). A comparative study of K/Si(111)-3 x 1 and K/Si(111):B-2 root 3 x 2 root 3R30 interfaces allowed us to determine the saturation coverage to be 0.5 monolayer in the later case. The 2 root 3-surface reconstruction is shown to be a common property of pure K, Rb, Cs materials and K0.4Rb0.6 alloys but progressively disappears if Rb is replaced by Ca. Taking into account the existence of two distinct boron sites in the ratio 1/3 as seen from B-1s core levels spectra, LAPW-DFT calculations have been carried out in order to optimize the atomic structure. As a result, alkali adatoms are shown to form trimers leading to a large modulation of the Si B bonds accompanied by an inhomogeneous doping of the dangling bonds in agreement with voltage dependent STM images

Published
2013

32. Etudes STM et DFT d'une molécule de porphyrine individuelle sur un substrat semi-conducteur

Author

El Garah, Mohamed, Makoudi, Younes, Palmino, Frank, Duverger, Eric, Sonnet, Philippe, Chaput, Laurent, Gourdon, André, Cherioux, Frederic, Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174) (FEMTO-ST), Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Laboratoire de physique et de spectroscopie électronique (LPSE), Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS), Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), ANR-07-JCJC-0053,SUPRAMEM,Mémoires Organiques Supramoléculaires(2007), Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)

Subjects
[CHIM.ORGA]Chemical Sciences/Organic chemistry, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Published
2010

37. First-principles phonon calculations of thermal expansion in Ti3SiC2, Ti3AlC2, and Ti3GeC2

Author

Togo, Atsushi, Chaput, Laurent, Tanaka, Isao, and Hug, Gilles

Subjects
Condensed Matter::Materials Science
Abstract

Thermal properties of ternary carbides with composition Ti3SiC2, Ti3AlC2, and Ti3GeC2 were studied using the first-principles phonon calculations. The thermal expansions, the heat capacities at constant pressure, and the isothermal bulk moduli at finite temperatures were obtained under the quasiharmonic approximation. Comparisons were made with the available experimental data and excellent agreements were obtained. Phonon band structures and partial density of states were investigated. These compounds present unusual localized phonon states at low frequencies, which are due to atomiclike vibrations parallel to the basal plane of the Si, Al, or Ge elements.

Published
2010

38. STM and DFT investigations of isolated porphyrin on a silicon based semiconductor at room temperature

Author

Baris, Bulent, El Garah, Mohamed, Makoudi, Younes, Palmino, Frank, Duverger, Eric, Chaput, Laurent, Sonnet, Philippe, Gourdon, André, Cherioux, Frederic, Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174) (FEMTO-ST), Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Laboratoire de physique et de spectroscopie électronique (LPSE), Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS), Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)

Subjects
[CHIM.ORGA]Chemical Sciences/Organic chemistry, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Published
2009

39. Calcul des propriétés de transport de matériaux thermoélectriques

Author

Chaput, Laurent, Laboratoire de physique des matériaux (LPM), Université Henri Poincaré - Nancy 1 (UHP)-Institut National Polytechnique de Lorraine (INPL)-Centre National de la Recherche Scientifique (CNRS), Institut National Polytechnique de Lorraine - INPL, and Pierre Pécheur

Subjects
calcul de structure électronique, phases MAX, electronic structure calculations, zinc, Hall effect, thermoelectric power, spectral differentiation, skutterudites, [SPI.MECA]Engineering Sciences [physics]/Mechanics [physics.med-ph], Lorenz number, nombre de Lorenz, effet Hall, half-Heusler, MAX phases, differentiation spectrale, pouvoir thermoélectrique
Abstract

A module for the calculation of transport properties has been implemented and applied to several compounds such as the elemental zinc, the MAX phases, the half-Heusler and the Skutterudites compounds. In this work we show that very simple hypothesis on the scattering mechanisms allow to calculate these coefficients quite accurately. These calculations remains therefore cheap and accurate enough to be used for the search of new thermoelectric materials. Moreover we show that electrons velocities can be calculated uite efficiently using the spectral differentiation method, what speed up the calculation. Finally, in the last chapter the exact exchange approximation is presented to calculate the electronic structure of strongly correlated systems; Un module de calcul des coefficients de transport a été implementé, puis appliqué à différents systèmes tels que le zinc pur, les phases MAX 312, les demi-Heusler, ou les Skutterudites. Dans ce travail nous montrons en particulier que des approximations simples pour les processus de diffusion suffisent à évaluer ces coefficients avec une précision raisonnable. Ainsi le coût de calcul reste suffisamment modeste pour envisager l'utilisation de ces calculs dans la recherche de nouveaux matériaux thermoélectriques. De plus nous montrons que le calcul des vitesses des électrons par la technique de différentiation spectrale donne de bons résultats ce qui accélère encore le calcul. Nous terminons ce travail par un chapitre sur l'approximation de l'échange exact pour le calcul de la structure électronique des systèmes fortement corrélés

Published
2006

40. Calculation of transport properties for thermoelectric compounds

Author

Chaput, Laurent, Laboratoire de physique des matériaux (LPM), Université Henri Poincaré - Nancy 1 (UHP)-Institut National Polytechnique de Lorraine (INPL)-Centre National de la Recherche Scientifique (CNRS), Institut National Polytechnique de Lorraine - INPL, Pierre Pécheur, and Jacquot, Magali

Subjects
calcul de structure électronique, phases MAX, electronic structure calculations, zinc, Hall effect, thermoelectric power, spectral differentiation, skutterudites, [SPI.MECA]Engineering Sciences [physics]/Mechanics [physics.med-ph], [SPI.MECA] Engineering Sciences [physics]/Mechanics [physics.med-ph], Lorenz number, nombre de Lorenz, effet Hall, half-Heusler, MAX phases, differentiation spectrale, pouvoir thermoélectrique
Abstract

A module for the calculation of transport properties has been implemented and applied to several compounds such as the elemental zinc, the MAX phases, the half-Heusler and the Skutterudites compounds. In this work we show that very simple hypothesis on the scattering mechanisms allow to calculate these coefficients quite accurately. These calculations remains therefore cheap and accurate enough to be used for the search of new thermoelectric materials. Moreover we show that electrons velocities can be calculated uite efficiently using the spectral differentiation method, what speed up the calculation. Finally, in the last chapter the exact exchange approximation is presented to calculate the electronic structure of strongly correlated systems, Un module de calcul des coefficients de transport a été implementé, puis appliqué à différents systèmes tels que le zinc pur, les phases MAX 312, les demi-Heusler, ou les Skutterudites. Dans ce travail nous montrons en particulier que des approximations simples pour les processus de diffusion suffisent à évaluer ces coefficients avec une précision raisonnable. Ainsi le coût de calcul reste suffisamment modeste pour envisager l'utilisation de ces calculs dans la recherche de nouveaux matériaux thermoélectriques. De plus nous montrons que le calcul des vitesses des électrons par la technique de différentiation spectrale donne de bons résultats ce qui accélère encore le calcul. Nous terminons ce travail par un chapitre sur l'approximation de l'échange exact pour le calcul de la structure électronique des systèmes fortement corrélés

Published
2006

42. Phonon-phonon interactions in transition metals

Author

70183861, Chaput, Laurent, Togo, Atsushi, Tanaka, Isao, Hug, Gilles, 70183861, Chaput, Laurent, Togo, Atsushi, Tanaka, Isao, and Hug, Gilles

Abstract

In this paper the phonon self-energy produced by anharmonicity is calculated using second-order many-body perturbation theory for all bcc, fcc, and hcp transition metals. The symmetry properties of the phonon interactions are used to obtain an expression for the self-energy as a sum over irreducible triplets, very similar to integration in the irreducible part of the Brillouin zone for one-particle properties. The results obtained for transition metals shows that the lifetime is on the order of 10−10 s. Moreover, the Peierls approximation for the imaginary part of the self-energy is shown to be reasonable for bcc and fcc metals. For hcp metals we show that the Raman-active mode decays into a pair of acoustic phonons, their wave vector being located on a surface defined by conservation laws.

Published
2011

43. First-principles phonon calculations of thermal expansion in Ti3SiC2, Ti3AlC2, and Ti3GeC2

Author

70183861, Togo, Atsushi, Chaput, Laurent, Tanaka, Isao, Hug, Gilles, 70183861, Togo, Atsushi, Chaput, Laurent, Tanaka, Isao, and Hug, Gilles

Abstract

Thermal properties of ternary carbides with composition Ti3SiC2, Ti3AlC2, and Ti3GeC2 were studied using the first-principles phonon calculations. The thermal expansions, the heat capacities at constant pressure, and the isothermal bulk moduli at finite temperatures were obtained under the quasiharmonic approximation. Comparisons were made with the available experimental data and excellent agreements were obtained. Phonon band structures and partial density of states were investigated. These compounds present unusual localized phonon states at low frequencies, which are due to atomiclike vibrations parallel to the basal plane of the Si, Al, or Ge elements.

Published
2010

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