| 摘要 |
PURPOSE:To obtain the title medium having excellent reproducing output and C/N in the high-frequency region and with less decrease in the reproducing output due to repeated tests by jointly using hexagonal ferrite magnetic powder and acicular ferromagnetic powder. CONSTITUTION:The hexagonal ferrite magnetic powder having >=5 squareness ratio and >=600Oe coercive force is selected and the ferromagnetic powder having >=4 acicular ratio, >=100emu saturation magnetization and >=700Oe coercive force is selected. Less than 70pts.wt. hexagonal ferrite magnetic powder is used with 30-100pts.wt. ferromagnetic powder. More preferably, about 30-95wt% ferromagnetic powder is used with 70-5wt% hexagonal ferrite magnetic powder. In addition to the mixing ratio, the coercive force of the hexagonal ferrite magnetic powder is preferably regulated to about 700-1500Oe and the coercive force of the ferromagnetic powder is adjusted to about 700-1500Oe to improve the reproducing output in the high-frequency region.
|
