Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5496257 | Physics Letters A | 2017 | 5 Pages |
Abstract
Combining first-principles calculations with quasiharmonic approximation and Boltzmann transport equation we take light ionic crystals LiH and NaH as examples to systematically investigate the lattice thermal properties. Remarkably, thermal expansion (TE) effect plays a significant role in heat transport of these light solids, which makes the lattice thermal conductivity κL reduce about 40% compared with the value excluding the TE effect. As a result, the calculated κL of LiH is 14.67 (12.98)Wmâ1Kâ1 at 300 (327) K, which is well consistent with the experimental value of 14.70 (12.47)Wmâ1Kâ1 at the same temperature. Our analyses reveal that the TE effect lead to the reduction of phonon frequency and group velocity, the enhancement of phonon scattering processes and scattering rate, and consequently the reduction of κL. These results support that TE effect is a considerable factor in calculations of κL in light materials.
Keywords
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Physics and Astronomy (General)
Authors
Xiuxian Yang, Yinchang Zhao, Zhenhong Dai, Muhammad Zulfiqar, Jingzhong Zhu, Jun Ni,