The origin of high-saturation magnetization in Co-Zr-C melt-spun ribbons

The phases and magnetic properties of Co-Zr-C melt-spun ribbon were studied. The Co₈₀Zr₂₀ melt-spun ribbon consisted of a metastable Co₅Zr phase together with fcc-Co and Co₂₃Zr₆ phases and showed a high coercivity. The small substitution of C for Zr in the Co-Zr melt-spun ribbon resulted in the increase in the saturation magnetization. However, the substitution resulted in the decrease in the coercivity. Unlike the Co-Zr melt-spun ribbon, annealing of the Co-Zr-C melt-spun ribbon resulted in the further decrease in the coercivity. Thermomagnetic studies showed that the Co-Zr-C melt-spun ribbon consisted of the new magnetic phase with a high Curie temperature and a high-saturation magnetization. X-ray diffraction studies of the Co-Zr-C melt-spun ribbon revealed that the new magnetic phase with a high Curie temperature and a high-saturation magnetization is believed to be the Co₁₁Zr₂ phase.