| 摘要 |
PURPOSE:To reduce the noise obtg. excellent high density recording property by a method wherein iron oxide powder as magnetic powder contained in magnetic layer is utilized as nuclear crystal whereon the specified tranoxide magnetic powder contg. Co is used. CONSTITUTION:A substrate is coated with the needle-like uniaxial anisotropic iron oxide magnetic powder contg. Co with coercive force exceeding 700 oersted and particle diameter not exceeding 0.3mum and surface layer mainly containing Co on a nuclear crystal comprising oxide magnetic power together with a resin binder resin. In this case, if the particle diameter exceeds 0.3mu, the surface smoothness of the magnetic layer is deteriorated making it impossible to reduce the noise sufficiently. On the other hand, if the coercive force does not exceed 700 oersted, the sufficient output will not be supplied since the self demagnetizing loss in the short wave length will increase remarkably. |
