Site-diluted Blume–Capel model for the Fe–Al disordered alloys

Abstract

The phase-diagram of a site-diluted spin-1 Blume–Capel model on a simple cubic lattice is studied by using the mean-field renormalization group approach in the pair approximation. The critical temperature has been obtained as function of the vacant sites concentration and the crystal-field. Considering exchange and superexchange interactions between Fe atoms we applied this model to the description of the thermodynamic properties of Fe–Al alloys. The experimental phase diagram has been adjusted with the theoretical parameters and compared with previous theoretical results.