| 摘要 |
PURPOSE:To obtain the titled powder having a uniform particle size, superior magnetization and coercive force by adding a Co compd. to a specified suspension to obtain fine platy particles of Co-contg. Ba ferrite and by suspending the particles in an alkaline aq. soln. contg. Ti (IV). CONSTITUTION:A Co compd. such as CoCl2 is added to an alkaline iron (III) hydroxide (e.g., FeCl3) suspension contg. Ba ions in the form of Ba(OH)2 or the like and hydrothermal treatment is carried out at 150-330 deg.C to obtain fine platy particles (A) of Co-contg. Ba ferrite having <0.1mum particle size. The amt. of the Co compd. added is 2-13atom% of the amt. of Fe (III). An alkaline aq. soln. (B) contg. a Ti compd. such as TiCl3 by an amt. satisfying 0<Ti (IV)/Fe (III)<=13atom% is then added to the particles A to prepare a suspension. After the surfaces of the particles A are coated with Ti (IV) hydroxide by filtering and drying the suspension, the particles A are baked at 600-1,000 deg.C to obtain fine platy Ba ferrite powder having 300-1,000 Oe coercive force.
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