| 摘要 |
PURPOSE:To achieve a magnetic substance body which has high SN ratio at high density recording and suppresses the lowering in the reproduced output at a low recording ensity, by using fine granular magnetic particle for outermost magnetic layer and needle shape magnetic particle to other magnetic substance layer. CONSTITUTION:The vertical residual magnetizing rate is increased and high recording density is achieved, by using particle <=0.3mu in diameter, as the ferromagnetic particles for the outermost magnetic substance layer, and needle shaped particles in which the ratio of length/width is >=3 used as ferromagnetic particle for the lowermost magnetic substance layer, allowing to give in-surface orientation gradient. |
