| 摘要 |
PURPOSE:To obtain a nonmagnetic metallic base layer which has good contactness with an alloy substrate and is smaller than chromium in film thickness where the same coercive force is obtained by covering the alloy substrate with a nonmagnetic alloy layer, and forming the nonmagnetic metallic base layer made of molybdenum or tangsten thereupon. CONSTITUTION:An aluminum alloy disk which is so finished as to have a surface with sufficiently small undulations by lathe work and heat correction as the alloy disk 1 is plated with nonmagnetic alloy 2 and nickel-phosphorus alloy to about 50mum thickness, and this nickel-phosphorus plating film is polished into a specular surface up to 0.02mum maximum surface roughness and 30mum thickness. Then, this nickel-phosphorus plating film is coated with molybdenum as the metallic base layer 3 by a high-frequency sputtering method to 0.5mum. The base layer 3 increases the coercive force of the metallic magnetic medium 4 as shown in a figure. Then, the molybdenum sputtered film is coated with cobalt to 500Angstrom as the metallic magnetic medium 4 by the high-frequency sputtering method. Further, this metallic magnetic medium 4 is coated with SiO2 to 200Angstrom thickness by the high-frequency sputtering method to obtain a magnetic disk. |
