sAGNETO−OPTICAL RECORDING MEDIUM AND ITS PRODUCTION METHOD

摘要

A magneto−optical disk (1) comprises a disk substrate (2) having lands and grooves on and in a major surface thereof, a first dielectric layer (3), a multilayer magnetic film (10) including a first magnetic layer (4) having a vertical magnetic isotropy at room temperature, a second magnetic layer (5) having a plane magnetic isotropy at room temperature, and a third magnetic layer (6) having a vertical magnetic isotropy at room temperature, a second dielectric layer (7), a reflective layer (8), and a protective layer (9) all the layers and film being formed on the disk substrate (2) in order. The saturation magnetization of the second magnetic layer (5) is 8.80×10−2 to 1.76×10−1 Wb/m2. The gas pressure under which the second magnetic layer (5) is formed is 0.6 to 3.0 Pa. The third magnetic layer (6) contains 15 to 17 atom% of Co.