| 摘要 |
PROBLEM TO BE SOLVED: To obtain a recording medium having a good short wavelength output and S/N and excellent in overwrite characteristic by specifying the respective ranges of the average major axis length and average acicular ratio of ferromagnetic metallic powder and the fluctuation coefft. of the acicular ratio. SOLUTION: A ferromagnetic metallic powder having an average major axis length of 30 to 120 nm, an average acicular ratio of 3.0 to 10.0 and a fluctuation coefft. of the acicular ratio of 5 to 30% is selected as the ferromagnetic metallic powder having a specific size distribution. The average major axis length of the ferromagnetic metallic powder is specified preferably to 30 to 110 nm, further preferably to 35 to 105 nm to make the surface roughness of the magnetic recording medium smaller. The average acicular ratio of the ferromagnetic metallic powder is specified preferably to 3.5 to 10.0. If the fluctuation coefft. of the acicular ratio is as small as this range and the average major axis length and average acicular ratio are in this range, the magnetic recording medium assuring high Hc and small dispersion of the Hc distribution is obtd.
|
