Phase transition, elastic and electronic properties of topological insulator Sb2Te3 under pressure: First principle study

作者：Lu, Qing; Zhang, Huai-Yong; Cheng, Yan^*; Chen, Xiang-Rong^*; Ji, Guang-Fu

来源：Chinese Physics B, 2016, 25(2): 026401.

DOI：10.1088/1674-1056/25/2/026401

• Sb2Te3
• phase transition
• elastic properties
• electronic properties

The phase transition, elastic and electronic properties of three phases (phase I, II, and III) of Sb2Te3 are investigated by using the generalized gradient approximation (GGA) with the PBESOL exchange-correlation functional in the framework of density-functional theory. Some basic physical parameters, such as lattice constants, bulk modulus, shear modulus, Young's modulus, Poisson's ratio, acoustic velocity, and Debye temperature Theta are calculated. The obtained lattice parameters under various pressures are consistent with experimental data. Phase transition pressures are 9.4 GPa (I -> II) and 14.1 GPa (II -> III), which are in agreement with the experimental results. According to calculated elastic constants, we also discuss the ductile or brittle characters and elastic anisotropies of three phases. Phases I and III are brittle, while phase II is ductile. Of the three phases, phase II has the most serious degree of elastic anisotropy and phase III has the slightest one. Finally, we investigate the partial densities of states (PDOSs) of three phases and find that the three phases possess some covalent features.

• 出版日期2016-2
• 单位中国工程物理研究院; 中国工程物理研究院流体物理研究所; 四川大学