Melt-spun Sm(CoFeCuZr)zMx (M=B or C) nanocomposite magnets

The objective of this study was to produce a nanocrystalline Sm(CoFeCuZr)_z magnet consisting of magnetically hard Sm₂ Co₁₇/SmCo₅ phases and soft Fe(Co) phases. For this we have prepared melt-spun ribbons of Sm(Co_0.65Fe _0.28Cu_0.05Zr_0.02)_zB_x with z=7.0, 7.7, 8.5, 9.0, x=0, 0.5, 1.0, and Sm(Co_0.60Fe_0.23Cu_0.05Zr_0.02C _0.1)_z with z=7.7, 8.5, 9.0 and 9.5 and determined their crystallization temperatures, crystal structure, structure morphology and magnetic properties. It was found that the magnetic properties were very sensitive to the nominal composition and processing parameters. Increasing the boron content from x=0.5 to x=1.0 resulted in samples with higher α-Fe content and reduced coercivity. Energy products up to 8 MGOe and reduced remanence as high as 0.72 were observed. In general the boron containing samples gave higher values of coercivity and of reduced remanence because their microstructure was finer