Magnetic properties and microstructure of the dual-phase nanocomposite magnet Sm3(Fe,Ti)29Nx/α-Fe

A new dual-phase nanocomposite magnet, made up of the well-coupled Sm3(Fe,Ti)29Nx and α-Fe nano-crystals, has been successfully fabricated by the melt-spun technique. Measurements of magnetic properties reveal that the hysteresis loop shows up the notable characteristics of single hard magnet in the well-crystallized samples. The electron microscopy investigations indicate that the grain sizes in our samples in general range from 30 to 60 nm for Sm3(Fe,Ti)29Nx and from 10 to 20 nm for α-Fe, grain boundaries between the Sm3(Fe,Ti)29Nx and α-Fe phases are clean without any impurities. These structural features are fundamentally compatible with direct exchange-coupling between these two magnetic phases.