Influence of magnetization on the reordering of nanostructured ball-milled Fe-40 at. % Al powders

Deformation and nanocrystallization created by ball milling in Fe-40 at. % Al powders give rise to a progressive structural disorder and a spontaneous magnetization. Annealing tends to restore the structurally ordered paramagnetic state. The ordering-disordering process brings about a volume change clearly related to the saturation magnetization. This effect is associated with variation of the density of states at the Fermi level. The reordering temperature exhibits an anomalous field dependence, which can be explained considering the combined effect of directional magnetic order and structural order.