Spin-1 antiferromagnetic Ising model. I. Bulk phase diagram for a binary alloy

Abstract

A spin-1 antiferromagnetic Ising model is introduced to simulate a binary alloy which undergoes crystallization as well as an order–disorder phase transition. The phase diagram is calculated in the mean-field approximation, and three phases are found: the gas(=low density) phase and the two solid (=high density) phases which are ordered and disordered. For some regions of model parameters the disordered-solid phase coexists with the gas phase, and for other regions with the ordered solid. In addition, for certain regions of parameters there is a gas–ordered solid coexistence, which is important in the growth of ordered crystals.