Lattice dynamics and thermal properties of CaxMg1−xS ternary alloys

We present results of ab initio calculations concerning lattice dynamical and thermal properties of MgS, CaS and their ternary mixed crystals CaxMg1−xS in zinc-blende structure. Results for the phonon modes, dielectric constants, Fröhlich coupling parameter, polaron effective mass, entropy and heat capacities are given for CaxMg1−xS within a composition range 0–1. Generally good agreement is obtained between our results and data available in the literature. Other case, our results are predictions.

• Temperature dependence of entropy and heat capacities in CaxMg1−xS mixed crystals. • Compositional dependence of optical phonon modes in CaxMg1−xS mixed crystals. • Polaron and related properties in CaxMg1−xS mixed crystals.