High pressure structural phase transition of three diluted magnetic semiconducting compounds

410-413The high-pressure structural properties of three diluted magnetic semiconductor (DMS) compounds, viz Zn₁₋xMxSe (M=Cd, Fe and Mn) have been studied theoretically. The value of M-mole fraction x is given 0.16% for Fe, 0.1% for Cd and 0.24% for Mn. In order to investigate the high-pressure properties of these compounds, the two body potential approach has been used, which includes Coulomb term, short range repulsion and van der Waal interactions. It has been established that the potential used predict correctly the stability of zinc blende structure (ZBS) at ambient pressure. A good agreement between the experiment and the theoretical results has been achieved. The lattice parameter of all DMS ternary alloys obeys Vegards law very closely showing the linear dependence of lattice parameter on impurity composition. The 11.8, 9.3 and 9.2 GPa as phase transition pressure and 17%, 18.8% and 19% as percentage volume collapse for ZnFeSe, ZnMnSe and ZnCdSe alloys respectively, have been reported. This shows that these compounds get largely compressed during phase transition, though the % volume collapse overestimates the measured values. It has also been observed that the values of phase transition pressure for these alloys are less than their parent compound ZnSe (Pt= 14.4 GPa