Effect of additives on the magnetic properties and microstructure of melt spun SmCo 6.9Hf 0.1M 0.1 (M = B, C, Nb, Si, Ti) ribbons

Abstract

Effect of additives on the magnetic properties, phase evolution, and microstructure of SmCo 6.9Hf 0.1M 0.1 (M = B, C, Nb, Si, and Ti) ribbons by melt spinning technique under sufficient supercooling condition have been investigated. Among those additives, C is the most effective element in refining the grain size of SmCo 6.9Hf 0.1M 0.1 ribbons, from 100–400 nm for ternary ribbons to 30–100 nm for C-containing ribbons. Besides, C addition also induces extremely fine fcc-Co grains (5–10 nm) in the matrix, resulting in the stronger intergranular exchange coupling effect and the improved magnetic properties. The optimal magnetic properties of B r = 6.9 kG, i H c = 11.8 kOe and (BH) max = 10 MGOe could be achieved for SmCo 6.8Hf 0.1C 0.1 nanocomposite ribbons.