Abstract
Understanding the lattice thermal conductivity at high temperatures is important for many applications. We characterize phonon quasiparticles numerically through a hybrid approach that combines first-principles molecular dynamics and lattice dynamics. We find no lower-bound limits on phonon mean free paths in the perovskite. This contradicts the widely used minimal mean free path idea. The clear identification of phonon quasiparticles validates the use of a phonon gas model when the phonon mean free paths are shorter than the lattice constants of solids. Using the phonon quasiparticle properties, we have calculated the lattice thermal conductivity of the perovskite. The results are reasonable compared to recent experimental measurements.
- Received 4 February 2017
- Revised 20 June 2017
DOI:https://doi.org/10.1103/PhysRevB.96.100302
©2017 American Physical Society