Magnetic properties, phase evolution, and microstructure of melt spun SmCo7-xHfxCy (x=0–0.5; y=0–0.14) ribbons.

Magnetic properties, phase evolution, and microstructure of melt spun SmCo7-xHfxCy (x=0–0.5; y=0–0.14) ribbons via direct quenching have been investigated. For SmCo7-xHfx series ribbons, proper volume fraction of Hf is effective to stabilize and increase the magnetocrystalline anisotropy field of the TbCu7-type structure. Accordingly, the optimal magnetic properties of Br=6.4 kG, iHc=7.3 kOe, and (BH)max=8.7 MG Oe could be obtained for x=0.1. Furthermore, a slight C addition to above alloys is helpful in refining the grain size of the ribbons from 100–400 nm for C-free to 10–80 nm for C-containing samples. As a result, the magnetic properties are further improved to Br=6.9 kG, iHc=11.8 kOe, and (BH)max=10.6 MG Oe for SmCo6.8Hf0.2C0.12 nanocomposite ribbons. [ABSTRACT FROM AUTHOR]