| 摘要 |
PURPOSE:To enhance frequency characteristics, by forming the upper magnetic layer of the magnetic layer having a 2-layered structure using magnetic iron oxide powder having a surface layer of Co. CONSTITUTION:A magnetic layer with about 500-800Oe coercive force is formed on a substrate using magnetic iron oxide powder such as powder of gamma-Fe2O3, Fe3O4, gamma-Fe2O3 contg. Co or Fe3O4 contg. Co. A magnetic layer having a larger coercive force than said under magnetic layer is then formed on the under magnetic layer using uniaxially anisotropic needlelike magnetic powder having <=0.3mum particle size. The magnetic powder is obtd. by forming a Co- base surface layer on magnetic iron oxide powder as nuclear crystals. |
