Magnetism of Fe-Al disordered alloys: An Ising-Monte Carlo approach

Using a model of atoms randomly distributed on a cubic lattice, we have sim ulated the atomic disorder induced in quenched binary alloys. Our study has been developed within the framework of a random site-diluted Ising model w ith nearest-neighbor interactions and used a Monte Carlo algorithm implemen ted with Metropolis kinetics for sampling states. After equilibration, ense mble and configurational averages for magnetization, magnetic susceptibilit y, and heat capacity were computed. We conclude that, in agreement with pre vious experimental Mossbauer data for which a comparison is carried out, Fe -Al disordered alloys exhibit room-temperature ferromagnetic behavior up to around 43 at. % Al, beyond which the system becomes paramagnetic. This res ult contrasts with that for alloys with atomic order, which exhibit ferroma gnetism only up to 30 at. % Al. (C) 2001 American Institute of Physics.