Production of Co-B Alloy Powders by Chemical Reduction

抄録

Co-B powders were prepared by chemical reduction. The powders had a spherical shape with an average diameter of about 0.1μm. X-ray diffraction and differential scanning calorimetry studies confirmed that the powders were amorphous. The amorphous powders showed lower saturation magnetization than the crystalline counterparts. Heat treatment of the powders above the crystallization temperature resulted in the formation of fcc Co, hcp Co, Co₂B, and Co₃B phases. The saturation magnetization of the annealed powders monotonically increased as the annealing temperature increased. On the other hand, the coercivity of the annealed powders rapidly increased with increasing annealing temperature. The powders annealed at 500°C had a saturation magnetization of 92 emu/g with a high coercivity of 1670 Oe.