Disclosing the structural, phase transition, elastic and thermodynamic properties of CdSe1−xTex(x = 0.0, 0.25, 0.5, 0.75, 1.0) using LDA exchange correlation

Abstract

The phase transition and structural, elastic, thermodynamic characteristics of CdSe1−xTex alloys for all compositions x (x = 0, 0.25, 0.5, 0.75, 1) in both hexagonal wurtzite (WZ) and cubic zinc-blende (ZB) are studied at zero K and zero pressure in emphasis of the Full Potential Linearized Augmented Plane Wave (FP-LAPW) approach, in accordance with the Density Functional Theory (DFT). This was inserted within the WIEN2k code, alongside a local density approximation (LDA) in order to consider the exchange-correlation functional. For all compositions the CdSe1−xTex alloys were found to be mechanically stable for both phases ZB and WZ, and the strongest material among all structures is CdSe. Our findings reveal that the relation between elastic constants and the Te concentrations is not linear. The induced phase transition from ZB to WZ is studied at zero K, and the corresponding volume collapses at the phase transition boundary are calculated for all compositions x (x = 0.0, 0.25, 0.50, 0.75). Our results show that for all compositions of the CdSe1−xTex alloys, the stable phase is zinc-blende. Furthermore, the elastic characteristics of ZB and WZ phases of CdSe1−xTex alloys, alongside elastic constants, bulk modulus and shear modulus were determined and assessed in comparison with other theoretical and experimental findings available. A positive relationship was observed. Keywords: Phase transition, Elastic properties, Thermodynamic properties, ZB and WZ