Solid-Solid and Solid-Fluid Phase Transitions in Terms of the Lattice Model

Abstract

The order-disorder theory of a classical lattice model is used to obtain both the solid-solid phase transition and fluid-solid phase transition in a single system. In this model, the range of the interatomic potential is extended up to the fourth-neighbor distance. If the potential is suitably chosen, it is shown that the phase transitions between the bcc solid and fcc solid, between the bcc solid and fluid, and between the fcc solid and fluid occur within the Bragg-Williams approximation. The results are shown by the phase diagrams.