| 摘要 |
PURPOSE:To obtain the title medium having an excellent producing output in the high-frequency region and an excellent erasing characteristic and further having excellent durability 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, 60-100emu/g saturation magnetization and <=700Oe coercive force is selected. Less than 80pts.wt. ferromagnetic powder is used with 20-100pts.wt. hexagonal ferrite magentic powder. More preferably, about 20-95wt% hexagonal ferrite magnetic powder is used with about 80-5wt% ferromagnetic powder. In addition to the mixing ratio, the coercive force of the hexagonal ferrite magnetic powder is preferably regulated to about 400-600Oe and the coercive force of the ferromagnetic powder is adjusted to about 500-700Oe to improve the frequency characteristic.
|
