Nanocrystalline FeNbCuSiB magnetic alloys obtained by ball milling

We report the obtention of nanocrystalline FeSi alloys together with an amorphous phase by direct mechanical alloying of the constituents. Powders of the pure elements in the appropriate proportions (Fe73.sNb3CUlSi13.sB9 and Fe73.sNb3CUlSiI6.sB6), were mixed in a Reitch planetary ball mill for up to 120 hours. The resulting products were analyzed by X-ray diffraction and magnetic measurements. In all the cases an FeSi crystalline phase was present after a few hours of milling. Also an amorphous alloy develops simultaneously. The composition and size of the crystalline phases as well as the amount of the amorphous phase evolves during the milling. The evolution of coercive force, magnetic moment and the Curie temperature of the FeSi phase has been monitored. The coercive force decreases with increase milling time, but never reaches the low values of nanocrystalline materials obtained by heating metallic glasses of the same composition.