Importance of local force fields on lattice thermal conductivity reduction in PbTe1−xSex alloys
Importance of local force fields on lattice thermal conductivity reduction in PbTe1−xSex alloys
复制标题
DOI：
10.1209/0295-5075/102/46002
复制
发表时间：
2013-05
期刊：
影响因子：
--
通讯作者：
T. Murakami;T. Shiga;T. Hori;K. Esfarjani;J. Shiomi
中科院分区：
文献类型：
--
作者：
T. Murakami;T. Shiga;T. Hori;K. Esfarjani;J. Shiomi
PbTe1−xSex 合金晶体的晶格热导率是通过分子动力学模拟和从第一原理获得的非谐原子间力常数 (a-IFC) 计算得出的。纯PbTe和PbSe的a-IFC通过实空间位移法计算，同时考虑了分子动力学模拟的稳定性。已经开发了 a-IFC 的经验混合规则来解释合金中的质量和局部力场差异。所获得的晶格热导率降低的合金分数依赖性与实验非常吻合。对比研究表明，局部力场差异显着影响晶格热导率。
Lattice thermal conductivity of PbTe1−xSex alloyed crystals has been calculated by molecular-dynamics simulations with anharmonic interatomic force constants (a-IFCs) obtained from first principles. The a-IFCs of pure PbTe and PbSe were calculated by the real-space displacement method with care of the stability for molecular-dynamics simulations. An empirical mixing rule of a-IFCs has been developed to account for both mass and local force-field differences in alloys. The obtained alloy-fraction dependence of lattice thermal conductivity reduction agrees well with the experiments. The comparative study shows that the local force-field difference significantly impacts the lattice thermal conductivity.