Improved magnetic softness of (Fe0.5Co0.5)73.5Cu1Nb3-xMoxSi13.5B9 (x=1, 2, 3) nanocrystalline alloys by magnetic field annealing

The effects of magnetic field annealing on soft magnetic properties for nanocrystalline (Fe0.5Co0.5)(73.5)Cu1Nb3-xMoxSi13.5B9 (x=1, 2, 3) alloys are investigated. The results show that the magnetic softness of alloys is improved by the magnetic field annealing. The effective magnetic anisotropy < K > increases due to the arising of uniaxial anisotropy K-u, which is induced by the applied magnetic field. The initial permeability mu(i) is evidently enhanced by decreasing saturation magnetostriction lambda(S), which is attributed to the preferred domain orientation in the process of magnetic field annealing. Furthermore, the optimal high-temperature magnetic softness is obtained for the magnetic annealed sample with x=3, the mu(i) of which maintains a relative higher value above 650 degrees C.