Structural, electronic and thermal properties of ZnSiX[sub 2] (X=P, As) studied from first-principles theory

Abstract

The structural, electronic and thermal properties of ZnSiX2 (X=P, As) have been calculated using the full-potential linearized-augmented plane wave (FP-LAPW) method. The exchange and correlation potential is treated by an orbital independent modified Becke-Johnson (mBJ) potential as coupled with Generalized Gradient Approximation (GGA) for these calculations. The ground state properties such as lattice constants, bulk modulus and its pressure derivative are in good agreement with numerous experimental and theoretical data. The quasi harmonic Debye model, using a set of total energy versus volume calculations obtained with FP-LAPW method is applied to predict the thermal properties (thermal expansion coefficient (α), vibrational contribution to the volume and pressure constant heat capacities (Cv and Cp), isothermal and adiabatic bulk modulus (B and Bs), Debye temperature (θD) and Gruneisen parameter (γ). Further the temperature and pressure affects on the lattice parameter, bulk modulus and thermal expansion coefficient are determined.