Theoretical investigation of high-pressure phase transitions in Mg1-xSrxO

The stability of Mg1-xSrxO solid solution has been analyzed using charge transfer interaction potential (CTIP) model as well as density functional theory-based ab initio approach with Perdew-Burke-Ernzerhof (PBE) type parameterized generalized gradient approximation. The present CTIP model consists of long-range part as modified coulomb interactions and charge transfer forces whereas short-range part includes the van der Waals as well as Hafemeister Flygare type overlap repulsive interactions effective up to next nearest neighbor ions. The present study finds that under the influence of pressure host binary oxides as well as their solid solutions undergo B1B2 structural phase transition in the pressure range of 54-495 GPa. The variation of ground state properties and transition pressures have also been analyzed as a function of Sr composition. The observed results for the end point members are in agreement to their experimental counterparts and the deviations have been discussed in terms of interactions taken into consideration in two approaches.