Pressure induced phase transitions in semimagnetic semiconductors

Abstract

We have investigated the pressure induced phase transitions from zincblende (B3) to rocksalt (Bl) structures in semimagnetic semiconductors (SMS) Cd1−x, Mnx Z(Z=S, Se, Te) for (0 ≤ x ≤ 0.6). Besides, we have predicted the volume collapses (−ΔV(P1)/V/(O)) associated with the phase transitions in these materials. These predictions have been carried out by means of the three. body potential (TBP) approach developed by Singh and Singh (Phase Transitions, 1989, 15, 127). In this approach, the Gibbs free energy (G = U + P V − TS) is expressed as a function of three-body and van der Waals (vdW) interactions and the pressure at T = 0 K The phase transition (B3 → B1) pressures (P1 ) and associated volume collapses, computed from the TBP approach, are in reasonably good agreement with available experimental data. Also, we have found that the phase transition pressures decrease linearly with concentration (x) while the volume collapses increase with x, and these features are in keeping with available experimental data. Three body potential; Gibbs free energy; phase transition pressure; semimagnetic semiconductors; volume collapses.