基于第一性原理的铊-碲基热电化合物物理性质研究
Physical properties of Thallium-Tellurium based thermoelectric compounds using first-principles simulations
摘要：
采用密度泛函理论计算方法，研究了Tl_5Te_3，BiTl_9Te_6和SbTl_9Te_6化合物的热力学和物理性质.优化得到的化合物晶格常数与实验值符合较好。计算了三种化合物的电子态密度和能带结构，以了解它们的成键机制。BiTl 9 Te 6和SbTl 9 Te 6化合物的间接带隙分别为0.256eV和0.374eV。自旋-轨道耦合对两种半导体化合物的电子结构有重要影响，因此应该包括这些材料的良好的数值描述。计算了这三种化合物的弹性常数，测定了它们的体积模量、剪切模量和杨氏模量。Sb、Bi合金化后的韧脆转变与电子性质的变化有关。最后，得到了德拜温度、纵向声速、横向声速和平均声速。
英文摘要：
We present a study of the thermodynamic and physical properties of Tl5Te3, BiTl9Te6 and SbTl9Te6 compounds by means of density functional theory based calculations. The optimized lattice constants of the compounds are in good agreement with the experimental data. The electronic density of states and band structures are calculated to understand the bonding mechanism in the three compounds. The indirect band gap of BiTl9Te6 and SbTl9Te6 compounds are found to be equal to 0.256 eV and 0.374 eV, respectively. The spin-orbit coupling has important effects on the electronic structure of the two semiconducting compounds and should therefore be included for a good numerical description of these materials. The elastic constants of the three compounds have been calculated, and the bulk modulus, shear modulus, and young's modulus have been determined. The change from ductile to brittle behavior after Sb or Bi alloying is related to the change of the electronic properties. Finally, the Debye temperature, longitudinal, transverse and average sound velocities have been obtained.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
