Pressure dependent structural phase transition in iron silicide.

In the present paper, we have investigated pressure dependent structural phase transition and associated volume collapse at transition in Iron silicide (FeSi) through effective inter-ionic potential method. It has been shown that by applying an effective interionic interaction potential, which includes the long-range Coulomb, van der Waals (vdW) interaction and the short-range repulsive interaction up to second neighbor ions within the Hafemeister and Flygare approach provide successful evaluation of equation of state for change in volume with respect to the applied pressure. The phase transition pressure (Pt) at 13GPa is reported for FeSi, which is consistent with the available experimental data. This transition corresponds to transformation of B1(NaCl) type structure to B2(CsCl) type structure and is a first order phase transition. This first order phase transformation showed a volume collapse of FeSi is 10.2% at 13GPa. In addition, we have also predicted pressure dependent structural phase transition and volume collapse of 1wt% silicon doped Iron alloy (Fe0.91Si0.09) is 10.91% at 16 GPa. [ABSTRACT FROM AUTHOR]