Critical Behavior of a Magnetic Alloy

Abstract

A classical lattice model for a binary alloy which consists of a ferromagnetic and a non-magnetic component is investigated. Two coupling constants, a magnetic and a nonmagnetic one, describe the interactions between particles on nearest-neighbor sites. For vanishing magnetic coupling the model can be reduced to the Ising model from which the coexistence surface is determined exactly. The critical behavior is discussed extensively within the mean-field approximation. The critical line and the coexistence surface define three classes of directions (in the space of intensive variables) with respect to which the various critical exponents are calculated and classified.