| 摘要 |
PURPOSE:To obtain protective metallic film which does not shield an extremely magnetic field by adding at least one kind of Mo or Cu into a thin stainless steel film. CONSTITUTION:A thin amorphous rare earth-transition metal film 4,thin metallic film 6, dielectric film, etc., are provided on a transparent substrate 1. At least one layer of the thin metallic film 6 is so formed as to be the thin stainless steel film contg. at least either of Mo or Cu. A kind of martensite transformation is progressed by the internal stress generated at the time of forming film and the film is magnetized in the case of the thin 18-8 stainless steel film, but the magnetization induced by such stress is eliminated and the thin nonmagnetic stainless steel film is obtd. by adding at least either of Mo or Cu thereto. The protective film is, therefore, not magnetized and is lost of the magnetic shielding effect if the thin nonmagnetic stainless steel film is used as the protective film 5 of the magneto-optical recording medium.
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