Distributions of phonon lifetimes in Brillouin zones
Distributions of phonon lifetimes in Brillouin zones
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DOI：
10.1103/physrevb.91.094306
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发表时间：
2015-03-20
影响因子：
3.7
通讯作者：
Tanaka, Isao
中科院分区：
文献类型：
--
作者：
Togo, Atsushi;Chaput, Laurent;Tanaka, Isao
通过单模弛豫时间近似和第一性原理非谐晶格动力学计算的线性声子玻尔兹曼方程的完整解，计算了具有 33 种元素组合的闪锌矿和纤锌矿型化合物的晶格热导率。在九种闪锌矿型化合物中，详细讨论了声子线宽的分布（逆声子寿命）。声子线宽相对于波矢量非平滑变化，这是从自能的虚部解释的。研究表明，声子-声子相互作用强度和三声子选择规则的详细组合对于确定这些化合物的声子寿命至关重要。这表明在没有非简谐力常数的情况下定量预测声子寿命是困难的。然而，研究表明，仅根据简谐力常数计算的声子数加权的联合态密度可潜在地用于筛选材料的晶格热导率。
Lattice thermal conductivities of zincblende- and wurtzite-type compounds with 33 combinations of elements are calculated with the single-mode relaxation-time approximation and a full solution of the linearized phonon Boltzmann equation from first-principles anharmonic lattice dynamics calculations. In nine zincblende-type compounds, distributions of phonon linewidths (inverse phonon lifetimes) are discussed in detail. The phonon linewidths vary nonsmoothly with respect to wave vector, which is explained from the imaginary parts of the self-energies. It is presented that detailed combination of phonon-phonon interaction strength and three-phonon selection rule is critically important to determine phonon lifetime for these compounds. This indicates difficulty to predict phonon lifetime quantitatively without anharmonic force constants. However, it is shown that joint density of states weighted by phonon numbers, which is calculated only from harmonic force constants, can be potentially used for a screening of the lattice thermal conductivity of materials.