JPS6450255A - Magneto-optical disk - Google Patents

Abstract

PURPOSE:To relieve the dependency of a laser power necessary for recording on a linear speed and to simplify a device by forming a perpendicularly magnetized film which constitutes a recording film by changing the compsn. thereof in such a manner that the Curie temp. is lower from the inside circumference toward the outside circumference. CONSTITUTION:Two-sources sputtering is executed at the time of forming the recording film by high-frequency sputtering (RF sputtering) and the disposition of targets is so contrived that a component element (for example, Co) capable of raising Tc (Curie temp.) is much sputtered in the central part. Rare earth.transition metal elements (for example, Tb Fe Co) are much sputtered in the outside circumferential part so that the film thickness uniform from the inside to the outside circumferential part is eventually obtd. The magnetic film having the higher Tc from the outside circumferential part of the magneto- optical disk toward the inside circumferential part thereof is formed by changing the compsn. of the recording film in such a manner. The dependency of the laser power necessary for recording on the linear speed is thereby relieved and the device constitution is simplified.