Magnetic properties and thermal ordering of mechanically alloyed Fe–40 at% Al

A metastable, nanostructured, disordered bcc Fe–40 at% Al solid solution was produced from elemental powders using a high-energy ball mill. The effects of milling and subsequent annealing on (1) the formation of disordered nanocrystals, (2) changes in the lattice parameter and grain size, and (3) the disorder-to-order, ferromagnetic-to-paramagnetic transformations were studied by examination of both the microstructure and magnetic measurements. Oxidation and contamination of the powder during processing may play a significant role in the thermal ordering.