Magnetic softening of bulk amorphous FeCrMoGaPCB rods by current annealing technique

Abstract: Glassy rods of the Fe65.5Cr4Mo4Ga4P12C5B5.5 alloy were prepared by copper-mold casting technique under argon atmosphere with diameters of 1.5 and 1.8mm. As-quenched and dc current annealed (CA) samples were examined by thermal analysis (DSC), X-ray diffraction (XRD), thermomagnetic and magnetic measurements. The appearance of a wide supercooled liquid region ΔT x ≅60K and high reduced glass transition temperature T rg ≅0.57 indicated enhanced thermal stability against crystallization. Electrical resistivity (ρ ≅210–220μΩcm), coercive field (H C ≅3–10A/m), saturation polarization (J S ≅83emu/g) and Curie temperature (T C ≅448–460K) were determined in the as-cast “XRD-amorphous” state. Maximum improvement in coercivity of about 30% was observed after applying a heating power per square area of P S ≅4.4 and 3.7W/cm2 for 1.5 and 1.8mm rods diameters, respectively. Coercivity behavior after CA treatments indicates the presence of a very small volume fraction of nanoscale crystalline inclusions that apparently hinder stress relief. [Copyright &y& Elsevier]