PURPOSE: To obtain metal magnetic powder having high coercive force and a narrow distribution of coercive force by heating and reducing the particles after having coated the surface of needle-shaped water content iron oxide particles with a mixture layer containing a nickel compound-content vibalent transition metal compound.
CONSTITUTION: A mixture layer containing vibalent transition metal compound which includes at least a nickel compound, is applied to the surface of needle- shaped water-content iron oxide particles. When this water-content iron oxide particles are heated at a high temperature in a non-active gas current, there is formed ferrite having no hydrated hole substantially. Then, the ferrite is heated and reduced. This construction enables sintering during reduction and prevent disconnection and maintain their shape with ease so that magnetic metal powder of high coercive force and a narrow distribution of coercive force may be obtained. The magnetic metal powder thus obtained is excellent to a further extent, and what is more, they are excellent in terms of corrosion resistance.
ICHIKAWA HIROTSUGU
HAMA YOSHINORI
AOKI YOSHIO
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