Inelastic neutron scattering measurements of individual phonon lifetimes and dispersion at 295 and 1200 K have been used to probe anharmonicity and thermal conductivity in UO2. They show that longitudinal optic phonon modes carry the largest amount of heat, in contrast to past simulations and that the total conductivity demonstrates a quantitative correspondence between microscopic and macroscopic phonon physics. We have further performed first-principles simulations for UO2 showing semiquantitative agreement with phonon lifetimes at 295 K, but larger anharmonicity than measured at 1200 K.
J. W. Pang et al., "Phonon Lifetime Investigation of Anharmonicity and Thermal Conductivity of UO2 by Neutron Scattering and Theory," Physical Review Letters, vol. 110, no. 15, American Physical Society (APS), Apr 2013.
The definitive version is available at https://doi.org/10.1103/PhysRevLett.110.157401
Keywords and Phrases
Anharmonicities; First-principles simulations; Inelastic neutrons; Longitudinal optics; Phonon lifetimes; Phonon physics; Quantitative correspondence; Thermal conductivity
International Standard Serial Number (ISSN)
Article - Journal
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