Structural, elastic and thermodynamic properties of rock-salt structure CdSe at high temperature and high pressure

摘要

A theoretical study of the structural, elastic and thermodynamic properties of the rock-salt (RS) structure CdSe are presented in this paper by performing first principles calculations within local density approximation (LDA) based on Density Functional Theory (DFT). The values of lattice constant, bulk modulus and its pressure derivatives and elastic constants are in agreement with the available theoretical results. It is also found that the RS structure CdSe should be unstable above about 28 GPa. The pressure and temperature dependencies of the Heat capacity, Internal energy, Entropy, Helmholtz free energy, Grüneisen parameter, Thermal expansion coefficient and Debye temperature are obtained by the quasi-harmonic Debye model in the ranges of 0 - 1000 K and 0 - 28 GPa.