Specific features of microhardness and thermodynamic stability of the Cd1–xMnxTe solid solutions

Abstract

The features of fusion and growth of Cd1–xMnxTe (0.02 x  0.55) solid solution crystals as well as the dependence of their microhardness on the composition have been studied. Local maxima of the microhardness at x = 0.14 and 0.46 have been experimentally found. Thermodynamics of Cd1–xMnxTe formation in the delta-lattice parameter model has been considered, and the phase diagram of spinodal decomposition in these solid solutions has been found. The empirical pseudopotential method was used to analyze the distribution of the valence charge density during formation of the Cd1–xMnxTe solid solution and its effect on the rearrangement of chemical bonds. It has been shown that the stability of the solid solutions is defined not only by the difference in the lattice constants of the CdTe and MnTe binary compounds but also by the charge exchange between bonds with the different degree of ionicity and the change in the nature of chemical bonds.