Fe–Ni alloys have attracted interest as important magnetic alloys without rare-earth (RE) elements, which
exhibit a wide variety of magnetic properties depending on the atomic ratios of Fe and Ni. Here, we attempted
to synthesize Fe-Ni magnetic materials using a Fe based amorphous alloy precursor that is thermodynamically
metastable and has more open atomic packing structure than crystalline alloys. High energy ball milling was
applied to promote the formation of various Fe-Ni phases using mixtures of the amorphous precursor powder
and 10-50% crystalline Ni powder. The as-milled composite powders as well as the composite powders
annealed at 673 K were analyzed by X-ray diffractometer, differential scanning calorimeter, scanning electron
microscope, and vibrating sample magnetometer to investigate their magnetic properties in terms of phase
transformation behavior of the composite powders.