We show how to construct a Landau-type free energy based on a primary order parameter coupled to finite strain with an elastic energy derived from an arbitrary equation of state $V=V\left(P\right)$. The resulting class of models provides an excellent and efficient framework for the systematic study of phase transformations for a wide range of materials up to ultrahigh pressures.

• Received 6 September 2001

DOI:https://doi.org/10.1103/PhysRevLett.88.055503