Lattice Thermal Conductivity of MgSiO₃ Perovskite from First Principles.

ABSTRACT: We investigate lattice thermal conductivity κ of MgSiO₃ perovskite (pv) by ab initio lattice dynamics calculations combined with exact solution of linearized phonon Boltzmann equation. At room temperature, κ of pristine MgSiO₃ pv is found to be 10.7 W/(m · K) at 0 GPa. It increases linearly with pressure and reaches 59.2 W/(m · K) at 100 GPa. These values are close to multi-anvil press measurements whereas about twice as large as those from diamond anvil cell experiments. The increase of k with pressure is attributed to the squeeze of weighted phase-spaces phonons get emitted or absorbed. Moreover, we find κ exhibits noticeable anisotropy, with κ _zz being the largest component and [Formula: see text] being about 25%. Such extent of anisotropy is comparable

SUBMITTER: Ghaderi N 

PROVIDER: S-EPMC5511206 | biostudies-literature | 2017 Jul

REPOSITORIES: biostudies-literature