Baric polymorphism: characteristic functions and critical indexes

Abstract

Polymorphous phase transition induced by hydrostatic pressure has been considered as a percolating process. Host matrix of the initial solid phase with nuclei of a new phase arising therein due to phase transformation was treated as an inhomogeneous medium. Electrical conductivity of the medium was the control parameter for searching over the stage of phase transformation. Effective-medium approximation, based on the Bruggeman model, has been improved to fit with percolation theory postulates. Functional connections between volume fraction of a new polymorphous phase and a pressure value were calculated for three investigated cases: n-ZnO, n-GaAs, and n-InAs on the base of the proposed approach.

Keywords:

• polymorphous phase transition
• percolation
• effective media approximation

Notes

^†This paper was presented at the L^th European High Pressure Research Group (EHPRG 50) Meeting at Thessaloniki (Greece), 16–21 September 2012.