Lattice dynamical and elastic properties of mixed quaternary semiconducting alloys CuGa1-xAlxS2 and AgxCu1-xGaS2

Abstract

Ten parameter rigid-ion model is used to study the vibrational and elastic properties of mixed quaternary semiconducting CuGa1-xAlxS2 and AgxCu1-xGaS2 chalcopyrites alloys. The zone-centre phonon frequencies and the elastic properties of above mentioned alloys are calculated for the composition range 0 <= x <= 1. The main outcome of the present study is that the studied compounds are mechanically stable at all compositions of x. While the elastic constants C-33 and C-44 change sharply in comparison with other elastic constants for AgxCu1-xGaS2, all elastic constants of the CuGa1-xAlxS2 do not change too much with the increase in the concentration of Al-and Ag-atoms in CuGa1-xAlxS2 and AgxCu1-xGaS2 compounds.