Magnetostriction and effective magnetic anisotropy of Co-contained Finemet nanocrystalline alloys

摘要

The microstructure and magnetic properties of Co-contained Finemet nanocrystalline alloys were investigated. By contrasting with Finemet, the Co-contained Finemet nanocrystalline alloys have a broad temperature range for precipitating a single α-FeCo crystalline phrase and a relatively higher Curie temperature of amorphous phase. After full nanocrystallization they exhibit improved high-temperature soft magnetic properties. However the room-temperature permeability of Co-contained Finemet was obviously lower than that of Finemet. For clarifying the reason, the effective magnetic anisotropy (K) and the saturation magnetostriction λ_s, were measured, respectively, and the (K) of Co-contained Finemet is about 100-137 J/m~3, which is the same order of magnitude as Finemet, but the λ_s of Co-contained Finemet-type alloy is much higher than that of Finemet which results in a relatively lower permeability.