| 摘要 |
PURPOSE:To manufacture magnetic powder for a magnetic recording medium with high recording density by washing a hexagonal system ferrite composition with low coercive force contg. other atoms substituted for part of the constituent molecules to dissolve and remove the glass component, thereby depositing fine ferrite particles. CONSTITUTION:In order to control the coercive force of magnetoplumbite type ferrite represented by general formula AOnFe2O3 (where A is Ba or Sr and 5<=n<=6) as the basic composition of hexagonal system ferrite, C0<2+>-Ti<4+> ions are substituted for part of Fe<3+> ions in the ferrite, B2O3-BaO as a glass forming substance is added to the resulting ferrite, melted, and cooled very rapidly to form an amorphous ribbon. This ribbon is heated at 800 deg.C for 4hr to deposit hexagonal system fine Ba ferrite particles having about 0.1mum average particle size. By washing the particles with hot water, the glassy component is removed to manufacture magnetic powder for a magnetic recording medium. |
