Investigation on structure-magnetic property correlation in melt-spun Sm(Co0.56Fe0.31Cu0.04Zr0.05B0.04)z ribbons

The effect of microstructural variation on magnetic properties of Sm(Co0.56Fe0.31Cu0.04Zr0.05B0.04)z (z=8, 10 and 12) melt-spun ribbons was investigated. A high coercivity (iHc) of 11 kOe was obtained in as-spun ribbons of z=8. The ribbon had nanosized grains of ∼10 nm with 1:7H (TbCu7 type) as a major phase. The ribbon with a high z(z=12) displayed large grain size (∼50 nm) having 2:17H (Th2Ni17 type) as a major phase. Boron enriched precipitates were observed in both z=8 and 12 ribbons. The boron solubility in the 1:7H phase was more than that in 2:17H phase. The variation of coercivity with z was related to the grain size.