Strong Elastic Anisotropy of Low-Dimensional Ternary Compounds: InXTe 3 (X = Si, Ge)

The stability, anisotropic elastic behavior and electronic properties of trigonal In 2 Si 2 Te 6 , InSiTe 3 , In 2 Ge 2 Te 6 , and InGeTe 3 compounds have been studied by first-principles calculations. The exchange-correlation energy of electrons has been treated using the Perdew–Burke–Ernzerhof parametrization. The calculated formation energies and elastic constants show that all the compounds are both thermodynamically and mechanically stable. Mechanical properties such as the bulk modulus, shear modulus, Young's modulus, Poisson's ratio, B/G ratio, Debye temperature, and sound velocity are discussed in detail. We have analyzed their anisotropic indexes and elastic anisotropies by three-dimensional surface constructions. The present results indicate that the compounds are elastically strongly anisotropic. These materials are found to be semiconductor in nature with indirect band gaps by the analysis of their electronic structures. It can be expected that all the compounds have low thermal conductivity.