SPINDLE-LIKE GEOTHITE PARTICLE POWDER, ITS PRODUCTION, SPINDLE-LIKE METAL MAGNETIC PARTICLE POWDER CONSISTING MAINLY OF IRON AND OBTAINED BY USING THE SAME GEOTHITE PARTICLE POWDER AS STARTING RAW MATERIAL AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To obtain spindle-like geothite particle powder having uniform particle diameter, not mixing dendritic particles and having proper particle shape and large axial ratio and spindle-like metal magnetic particle powder obtained by using the spindle-like geothite particle powder as a starting raw material and containing iron having high coercive force and excellent distribution of coercive force as a main component. ;SOLUTION: This spindle-like geothite particle powder comprises spindle-like particles having 0.05-1.0μm average long shaft diameter and the particles are composed of a geothite seed crystal part and a geothite surface layer part and the geothite seed crystal part contains Co in an amount of 0.5-25atom% based on total Fe and the surface layer part contains Al in an amount of 0.5-15atom% based on total Fe.;COPYRIGHT: (C)1997,JPO