Impact of Ni and P substitution for B on the structure and soft magnetic properties of FeBPCuNb amorphous/nanocrystalline alloy

Alloying is usually an indispensable approach to optimize the magnetic performance of Fe-based amorphous/nanocrystalline alloys. This study focuses on tailoring the composition of the Fe_81.5B_10-xP_7.5Cu_0.5Nb_0.5M_x (M=Ni & P, x = 0, 1, & 2 at. %) alloys by substituting the B element with Ni and P. The substitution of ferromagnetic element Ni enhances the saturation magnetic induction intensity and the incorporation of P improves the amorphous formation ability and reduces coercivity. Moreover, substituting B elements with Ni and P widens the optimal heat treatment range. Additionally, the study explores the soft magnetic properties and microstructure evolution as functions of the annealing temperature based on the DSC analysis. The results reveal that the P8.5 alloy exhibits fine grains (16.5 nm) and low coercivity (3.5 A/m) coupled with high saturation magnetic induction intensity (1.77 T) after annealing.