Thermal stability and magnetic properties of Co–Fe–Hf–Ti–Mo–B bulk metallic glass

A new ferromagnetic Co–Fe–Hf–Ti–Mo–B bulk metallic glass was produced by copper mould casting method, using industrial raw materials. The magnetic properties were studied with the high-performance hysteresis loop tracer. The low coercivity, as low as 2 A/m for the as-cast sample, was found in the Co–Fe-based metallic glass rod with a diameter of 1.5 mm, the saturation magnetization is 0.6 T. The thermal stability was characterized by differential thermal analysis, X-ray diffraction was used to confirm the amorphous state of as-cast alloy and to perform the structural analysis of crystallization products. Crystallization temperature exceeding 900 K and supercooled liquid region of 35 K were found in the investigated glass. The high glass forming ability was explained by the slow nucleation rate of intermetallic compounds which are structurally complex in multicomponent system during solidification. High crystallization temperature suggests that the studied bulk metallic glass could be used as high-temperature soft magnetic material.