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Your search keyword '"Delaire, O."' showing total 19 results
Start Over Author "Delaire, O." Journal physical review b
19 results on '"Delaire, O."'

1. The curious case of cuprous chloride: Giant thermal resistance and anharmonic quasiparticle spectra driven by dispersion nesting

Author

Mukhopadhyay, S, Bansal, D, Delaire, O, Perrodin, D, Bourret-Courchesne, E, Singh, DJ, and Lindsay, L

Abstract

Strongly anharmonic phonon properties of CuCl are investigated with inelastic neutron-scattering measurements and first-principles simulations. An unusual quasiparticle spectral peak emerges in the phonon density of states with increasing temperature, in both simulations and measurements, emanating from exceptionally strong coupling between conventional phonon modes. Associated with this strong anharmonicity, the lattice thermal conductivity of CuCl is extremely low and exhibits anomalous, nonmonotonic pressure dependence. We show how this behavior arises from the structure of the phonon dispersions augmenting the phase space available for anharmonic three-phonon scattering processes, and contrast this mechanism with common arguments based on negative Grüneisen parameters. These results demonstrate the importance of considering intrinsic phonon-dispersion structure toward understanding scattering processes and designing new ultralow thermal conductivity materials.

Published
2017

11. Temperature and pressure dependence of the Fe-specific phonon density of states inBa(Fe1−xCox)2As2

Author

Delaire, O., primary, Lucas, M. S., additional, dos Santos, A. M., additional, Subedi, A., additional, Sefat, A. S., additional, McGuire, M. A., additional, Mauger, L., additional, Muñoz, J. A., additional, Tulk, C. A., additional, Xiao, Y., additional, Somayazulu, M., additional, Zhao, J. Y., additional, Sturhahn, W., additional, Alp, E. E., additional, Singh, D. J., additional, Sales, B. C., additional, Mandrus, D., additional, and Egami, T., additional

Published
2010
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12. Effects of vacancies on phonon entropy ofB2FeAl

Author

Lucas, M. S., primary, Delaire, O., additional, Winterrose, M. L., additional, Swan-Wood, T., additional, Kresch, M., additional, Halevy, I., additional, Fultz, B., additional, Hu, Jingzhu, additional, Lerche, M., additional, Hu, M. Y., additional, and Somayazulu, M., additional

Published
2009
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13. Phonon density of states and heat capacity ofLa3−xTe4

Author

Delaire, O., primary, May, A. F., additional, McGuire, M. A., additional, Porter, W. D., additional, Lucas, M. S., additional, Stone, M. B., additional, Abernathy, D. L., additional, Ravi, V. A., additional, Firdosy, S. A., additional, and Snyder, G. J., additional

Published
2009
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19. Structural phase transition and phonon instability in Cu12Sb4S13.

Author

May, A. F., Delaire, O., Niedziela, J. L., Lara-Curzio, E., Susner, M. A., Abernathy, D. L., Kirkham, M., and McGuire, M. A.

Subjects
*PHASE transitions, *SPECIFIC heat capacity, *X-ray powder diffraction
Abstract

A structural phase transition has been discovered in the synthetic tetrahedrite Cu12Sb4S13 at approximately 88 K. Upon cooling, the material transforms from its known cubic symmetry to a tetragonal unit cell that is characterized by an in-plane ordering that leads to a doubling of the unit cell volume. Specific heat capacity measurements demonstrate a hysteresis of more than two degrees in the associated anomaly. A similar hysteresis was observed in powder x-ray diffraction measurements, which also indicate a coexistence of the two phases, and together these results suggest a first-order transition. This structural transition coincides with a recently-reported metal-insulator transition, and the structural instability is related to the very low thermal conductivity k in these materials. Inelastic neutron scattering was used to measure the phonon density of states in Cu12Sb4S13 and Cu10Zn2Sb4S13, both of which possess a localized, low-energy phonon mode associated with strongly anharmonic copper displacements that suppress k. In Cu12Sb4S13, signatures of the phase transition are observed in the temperature dependence of the localized mode, which disappears at the structural transition. In contrast, in the cubic Zn-doped material, the mode is at slightly higher-energy but observable for all temperatures, though it softens upon cooling. [ABSTRACT FROM AUTHOR]

Published
2016
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