Structural, electronic and thermodynamic properties of Sr_xCa_1‐xS: A first‐principles study

Abstract

The principal purpose of this work is to further the understanding of the structural, electronic, and thermodynamic properties of the SrxCa1–xS alloys (0≤x ≤1) in Rock‐salt phase using the full potential augmented plane wave (FP‐LAPW) method within density functional theory. The exchange‐correlation potential for structural properties was calculated by the standard local density approximation (LDA) and GGA (PBE) and the new form of GGA (WC) which is an improved form of the most popular Perdew‐Burke‐Ernzerhof (PBE), while for electronic properties, the alternative form of GGA modified by Becke‐Johnson exchange correlation potential (MBJ) was also applied. It is shown that investigation on the effect of composition on lattice constant, bulk modulus, and band gap for ternary alloys shows almost nonlinear dependence on the composition. On the other hand, the thermodynamic stability of these alloys was investigated by calculating the excess enthalpy of mixing ΔHm as well as the phase diagram. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)