Bethe‐Peierls‐Weiss approximation in disordered ferromagnets

The behavior of ferromagnetic atoms in a structurally disordered non‐magnetic host is analyzed within the Bethe‐Peierls‐Weiss (BPW) approximation. The structural disorder, which is assumed to cause fluctuations in the exchange interactions, is found not to affect the value of the concentration of magnetic atoms (Cm) for the onset of ferromagnetism; however, above Cm, the Curie temperature relative to the Curie temperature of the averaged system is reduced by such fluctuations. The special case of structural disorder alone is studied within the same approximation and our conclusions are compared with eariler results in the literature.