Structural, mechanical and thermal properties of Cu2ZnSiS4 with four structures from the first-principle calculations

Abstract

In this paper, the structural, mechanical and thermal properties of the four structures of Cu2ZnSiS4 were studied on the basis of density functional theory (DFT). The generalized gradient approximation (GGA) of Perdew–Burke–Ernzerhof (PBE) was used to treat the exchange related energy and potential of total energy calculation. The independent elastic constants of the four structures are calculated, which prove that they are mechanically stable. The bulk modulus, Poisson’s ratios and universal anisotropy indices of Cu2ZnSiS4 can be calculated from the obtained elastic constants. In addition, the variation of the bulk modulus with the pressure (0–25 GPa) and temperature (0–700 K) have been reported. In order to further study the compound, the thermal properties of the compound were analyzed by using the quasi-harmonic Debye model, including specific heat, thermal expansion coefficient and Debye temperature.