Effects of the Additives to Co-Zr Alloys on their Magnetic Properties

The structures and magnetic properties of Co-Zr and Co-Zr-M (M=B, C, Si, Al) melt-spun ribbons and those annealed specimens were studied with a x-ray diffractometer and a vibrating sample magnetometer. The Co-Zr melt-spun ribbons consisted of Co₅Zr and Co₂₃Zr₆ phases and showed a high coercivity. The small substitution of C for Zr in the Co-Zr alloy resulted in the increase in the saturation magnetization, but resulted in the decrease in both the remanence and coercivity. On the other hand, the small substitution of B for Zr in the Co-Zr alloy resulted in the increase in the remanence and coercivity. The small substitution of either Si or Al for Zr in the Co-Zr alloy resulted in the decrease in both the remanence and coercivity. Heat treatment of the melt-spun ribbons resulted in the further increase in the coercivity of Co-Zr-B alloys. However, annealing resulted in the decrease in the coercivity of the other Co-Zr-M (M=C, Si, Al) alloys.