Structure and magnetic properties of melt-spun ribbons of Sm(Co,Fe,Cu,Zr)_z with high cobalt content

In this work the investigation of structure and magnetic properties of SmCo_7.5Fe_3.09Cu_0.84Zr_0.3 and SmCo_7.52Fe_3.01Cu_0.84Zr_0.28 melt-spun ribbons with high cobalt content after different heat treatments was performed. The phase composition and magnetic properties of the samples were determined. Isothermal aging at 600-800 °C with subsequent slow cooling leads to the slight increase in coercivity of the samples. After arc-melting the phase composition of the samples is hexagonal Sm₂Co₁₇ and CoFe. After melt-spinning a small amount of the disordered SmCo₇ phase is detected. After aging metastable SmCo₇ disappears, and the phase structure is basically hexagonal phase Sm₂Co₁₇ and CoFe, except a tiny amount of SmCo₅ and rhombohedral Sm₂Co₁₇ after aging at 800 °C. Magnetic properties of the samples are relatively low because the phases, essential for the high-coercive state in these alloys, do not form during applied heat treatments. (paper)