Disordered ferromagnetic alloys — Effective medium

The transition temperature and critical concentration of randomly disordered A_χB_1?χ alloys, where A is the magnetic constituent of the alloy, have been investigated. The effects of second neighbor A-A and of nearest neighbor A-B interactions, both ferromagnetic and antiferromagnetic, have been included. Molecular field, assumed to hold within small enough regions, together with percolation theory are used to formulate an effective magnetic medium.