Soft Magnetic Properties and Mechanism of High Bs Fe83.2-Xcoxp10c6cu0.8 Amorphous Alloys Under Longitudinal Magnetic Field Annealing

Abstract

The Fe83.2-xCoxP10C6Cu0.8 amorphous alloys were synthesized by utilizing longitudinal magnetic field annealing (MF) with the aim of simultaneously improving the amorphous forming ability and soft magnetic properties. It is found that the amorphous forming ability and thermal stability of Fe83.2-xCoxP10C6Cu0.8 alloys are enhanced by Co addition while both MF and Co element doping effectively suppress the crystallization behavior during the annealing process. Meanwhile, the MF eliminates the pinning defects of the internal stress, adjusts the magnetic domain structure and local magnetic inhomogeneity, thereby significantly improving soft magnetic properties. The Fe73.2Co10P10C6Cu0.8 amorphous alloy under MF condition exhibits a high saturation magnetic flux density of 1.69 T, low coercivity of 2.9 A/m, and high relative permeability of 47,800. By magnetic domain structure observation, the soft magnetic mechanism of Fe83.2-xCoxP10C6Cu0.8 amorphous alloys under MF condition is clarified, which reveals that the effective permeability is dominated by the magneto-crystalline anisotropy whereas the coercivity and relative permeability mainly depend on the field-induced anisotropy. The results provide guide for developing amorphous alloys with high Bs and regulated soft magnetic properties.

Keywords: Fe-based amorphous alloys, Magnetic field annealing, Magnetic domain structure, Soft magnetic properties