Temperature dependent variations of phonon interactions in nanocrystalline cerium oxide

Abstract

The temperature dependent anharmonic behavior of the phonon modes of nanocrystalline CeO 2 was investigated in the temperature range of 80-440 K. The anharmonic constants have been derived from the shift in phonon modes fitted to account for the anharmonic contributions as well as the thermal expansion contribution using the high pressure parameters derived from our own high pressure experimental data reported previously. The total anharmonicity has also been estimated from the true anharmonicity as well as quasiharmonic component. In the line-width variation analysis, the cubic anharmonic term was found to dominate the quartic term. Finally, the phonon lifetime also reflected the trend so observed.