HIGH-PRESSURE STRUCTURAL PHASE-TRANSITION IN ALKALINE-EARTH CHALCOGENIDES

This paper reports on investigation of the pressure induced phase tran sition of BaSe, BaTe, SrSe and SrTe by using a three-body potential ap proach. The phase transition pressure and associated volume collapse o btained from this approach show a reasonably good agreement with exper imental data. The variation of phase transition pressure and (-Delta v /v(ol)). With Bulk modulus, and variation of phase transition pressure with ratio of cation to anion radius, follow a symmetric trend identi cal to that observed in other solids of this group. It is found that t he present model has promise to predict the phase transition pressure for alkaline earth chalcogenides. (C) 1998 Elsevier Science Ltd. All r ights reserved.