Magnetic properties of Co–P powders produced by chemical reduction

Co–P powders were produced by chemical reduction. The powders had a spherical shape with an average diameter of about 1 μm. X-ray diffraction and differential scanning calorimetry studies confirmed that the powders were amorphous. The amorphous powders showed higher saturation magnetization than the crystalline counterparts. Heat treatment of the powders above the crystallization temperature resulted in the formation of fcc Co, hcp Co, and Co2P phases. The saturation magnetization of the annealed powders monotonically decreased 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 600 °C had a saturation magnetization of 100 emu/g with a coercivity of 500 Oe.

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