| 摘要 |
PURPOSE:To provide a magnetic recording medium which can make effective magnetic recording by the simultaneous utilization of both of vertical and both-faces magnetization components and has excellent surface smoothness by using the magnetic powder of which the squareness ratios in the intra-surface longitudinal direction and perpendicular direction are both >=0.5 and the squareness ratio in the intra-surface direction perpendicular to the intra-surface longitudinal direction is made smaller than the squareness ratio in the intra-surface longitudinal direction. CONSTITUTION:The magnetic powder of the magnetic recording medium formed by providing a magnetic layer contg. hexagonal ferrite powder on a substrate is oriented in the perpendicular direction on the surface and in the intra-surface direction in the inside and the squareness ratios in the intra-surface longitudinal direction and the direction perpendicular to the magnetic layer are larger than 0.5; in addition the squareness ratio in the intra-surface direction perpendicular to the intra-surface longitudinal direction is smaller than the squareness ratio in the intra-surface longitudinal direction. The magnetic powder is the hexagonal ferrite powder which is expressed by the formula MAO.n(Fe1-xMBX)2O3. In the formula, MA denotes the element of at least >=1 kinds among Ba, Sr, Pb, Sb, etc. and controls the coercive force. (n) is preferably 5.0-6.0 and (x) is in a 0-0.2 range. The average grain size of the hexagonal ferrite powder is preferably 0.01-0.3mum and the ratio between the grain size and thickness is >=2:1. |
