| 摘要 |
PURPOSE:To necessitate the smaller optimum writing power of a laser and to improve corrosion resistance by forming a magneto-optical recording layer which has the axis of easy magnetization in the direction perpendicular to the film plane and has a specific thin quaternary amorphous alloy film. CONSTITUTION:The thin quaternary amorphous alloy film which has the axis of easy magnetization in the direction perpendicular to the film plane and is expressed by the formula (Tbx, Dy1-x)a (FeyCo1-y)1-z (where 0.35<x<0.54, 0.5<y<0.7, 0.2<z<0.27) is used as the magneto-optical recording layer. The optimum writing power changes like a quadratic curve with a change in the ratio of Co contained in the film and has the min. value. The optimum writing power can, therefore, be decreased to the lowest value if the content (1-y) (1-z) of Co of the magneto-optical recording layer is specified to 0.219-0.40. The smaller laser power is thereby necessitated and the deterioration of the recording medium is retarded; in addition, the corrosion resistance is greatly improved as the content of the easily corrosible rear earth is decreased.
|
