| 摘要 |
PURPOSE:To obtain a magnetic recording medium having high coercive force by successively laminating a nonmagnetic layer for heat accumulation having excellent heat conductivity and an NiP layer on a glass substrate. CONSTITUTION:A nonmagnetic layer 2 for heat accumulation, an NiP layer 3, a Cr underlayer 5, a magnetic recording layer 6 and a nonmagnetic protective layer 7 are successively formed on a glass substrate 1. The nonmagnetic layer 2 is formed on the surface of the glass substrate 1 smoothened by polishing with Cr, Ti, a Cr-Ti alloy, etc., having excellent heat conductivity and heat accumulating property in 500-2,000Angstrom thickness. The underlayer 5 is formed in 500-2,000Angstrom thickness and the magnetic recording layer 6 is formed with a Co alloy having magnetic anisotropy of uniaxial crystals, e.g., CoNiCr. Since the nonmagnetic layer 2 inhibits the rapid increase of the temp. of the NiP layer 3 at the time of heating the substrate 1 and prevents the reduction of the temp. of the substrate 1, the underlayer 5 and the magnetic recording layer 6 can be formed with satisfactory orientability of crystals and a magnetic recording medium retaining the flatness of the glass substrate 1 and having high coercive force can be obtd. |
