INFLUENCE OF MAGNETIZATION ON THE REORDERING OF NANOSTRUCTURED BALL-MILLED FE-40 AT. PERCENT AL POWDERS

Deformation and nanocrystallization created by ball milling in Fe-40 a t. % Al powders give rise to a progressive structural disorder and a s pontaneous magnetization. Annealing tends to restore the structurally ordered paramagnetic state. The ordering-disordering process brings ab out a volume change clearly related to the saturation magnetization. T his effect is associated with variation of the density of states at th e 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. [S0163-1829(98)51042- 9].