Effect of Nb addition on the magnetic properties and microstructure of FePCCu nanocrystalline alloy

The effects of Nb addition on the microstructure, crystallisation behavior, and soft magnetic properties of Fe83.25−xP9C7Cu0.75Nbx (x = 0, 0.5, 1, 2, 3) alloys were investigated. The experimental results demonstrate that proper Nb addition improves the glass-forming ability and enhances the soft magnetic properties of this alloy system. The Fe82.75P9C7Cu0.75Nb0.5 alloy annealed at 573–773 K for 10 min, in which α-Fe nanocrystalline phase with diameter of 5–20 nm precipitated from the amorphous matrix, while alloy annealed at 743 K shows the best soft magnetic properties. The resulting Fe82.75P9C7Cu0.75Nb0.5 nanocrystalline alloy exhibited a high saturation magnetic flux density, Bs, of 1.66 T; a low coercivity, Hc, of 6.8 A/m; and a high effective permeability, μe, of 29,000 at 1 kHz. These characteristics are superior to corresponding properties of FePC alloys. These results indicate that this alloy is a promising soft magnetic material.