Improvement of soft-magnetic properties for Fe-based amorphous alloys with high saturation polarization by stress annealing

Stress annealing is utilized for enhancing the magnetic softness of Fe83–xCoxB10Si3C3P1 (x = 0–16) amorphous alloys with saturation polarization up to 1.75 T. All of the stress-annealed alloys exhibit improved soft-magnetic properties, including low coercivity of 1.8–2.2 A/m, low core loss of 0.09–0.11 W/kg at 1.0 T and 50 Hz, and high permeability of 27,000–33,200 at 5 A/m and 1 kHz. Stress annealing induces longitudinal magnetic anisotropy and facilitates the annihilation of free volume, leading to pinning-free domain wall motion, and thus the enhanced magnetic softness. The induced magnetic anisotropy relates to the constrained elastic elongation introduced by stress annealing.