Bulk Permanent Magnet with Enhanced Anisotropy Fabricated by Magnetic Annealing from Fe-B-Nd-Nb Bulk Metallic Glass Precursor

Abstract

Fe68.16B20.16Nd7.68Nb4bulk metallic glass was annealed at 973 K for 15 min with or without external magnetic fields. The maximum energy product (BH)maxmeasured along the axial direction of a rod sample after annealed with a magnetic field parallel to the axis is 10.9 % higher than that annealed with a perpendicular field. The intrinsic coercivityiHcof the sample annealed with the parallel magnetic field reached 1014 kA/m. The induced magnetic anisotropy is attributed to the formation of preferred crystallographic orientation of ferromagnetic phases under the external magnetic field.