Physics Commons^™

Phonon Lifetime Investigation Of Anharmonicity And Thermal Conductivity Of Uo₂ By Neutron Scattering And Theory, Judy W. Pang, William J. Buyers, Aleksandr V. Chernatynskiy, Mark D. Lumsden, Bennett C. Larson, Simon R. Phillpot

Physics Faculty Research & Creative Works

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.