| 摘要 |
PURPOSE:To obtain minute and favorable hexagonal ferrite corpuscles without performing heat treatment at the glass crystallization method by a method wherein an admixture to hinder growth of particles is added into a molten raw material, and the cooling speed is suppressed to the critical speed or less necessary for vitrification. CONSTITUTION:23mol% Fe2O3 and 40mol% BaCO3 are mixed as the basic components of hexagonal ferrite, and moreover B2O3 30mol%, NiO 3.5mol% as an additive component for control of the magnetic characteristic, TiO2 3.5mol%, and one kind or two kinds out of SiO2, GeO2, Al2O3 are added to the degree of 0.5-15mol% as an admixture to obstruct growth of particles and to control the particle diameter, and after mixing and melting thereof, cooled at the speed of 10<3> deg.C/sec or more and 10<5> deg.C/sec or less of the critical speed or less necessary for vitrification. Thus obtained ribbon is extracted according to acetic acid directly, and passed through a washing process and a filtering process to obtain hexagonal plate type ferrite powder. |
