钴基金属微粉的制备及其磁性能

Preparation of Cobalt－ based Fine Alloy Powders and Magnetic Properties

采用水合肼作还原剂，从铁、钴、镍、铜盐的醇—水溶液中还原制备 Co1－ xFex、 Co1－ xNix合金微粉和 Cu/Co铜包钴微粉。采用 X射线粉末衍射 (XRD)、透射电镜 (TEM)、穆斯堡尔谱 (MS)和振动样品磁强计 (VSM)，对合成样品进行表征。 Co1－ xFex合金微粉为体心立方 (bcc)结构的固溶体，其颗粒形貌为由约 50 nm的四角片状微晶堆砌而成的约 300 nm的类球形团聚体。组成为 Co0.4Fe0.6的合金微粉，其比饱和磁化强度σ s=179.41 A· m2· kg－ 1，矫顽力 Hc=34.32 kA· m－ 1，而 Co0.6Ni0.4的合金微粉，其矫顽力较高， Hc=43.40 kA· m－ 1。

Cobalt－ based fine alloy powders Co1－ xFex,Co1－ xNix and coating Cu/Co have been synthesized from ethanol－ water solution of Fe, Co, Ni, Cu salts using hydrazine hydrate as the reducing agent. The powders were characterized by X－ ray powder diffraction(XRD), transmission electron microscopy (TEM) and vibrating sample magnetometer(VSM). The as－ prepared particle is a aggregate composed of many plannar tetragon crystallites. The crystalline size is about 30～ 50 nm and the aggregate size is about 300 nm. The Co1－ xFex alloy is a solid solution of bcc structure, and its magnetic properties are good, such as the Co0.4Fe0.6 alloy powder, specific saturation magnetizationσ s=179.41 A· m2· kg－ 1， coercivity Hc=34.32 kA· m－ 1.The Co1－ xNix alloys can provide with stability magnetic properties and higher coercivity, such as the Co0.6Ni0.4 alloy, coercivity Hc=43.40 kA· m－ 1.