Magnetooptic thin film, magnetoopic record medium

Abstract

This invention aims at providing magnetooptic thin film having a high Kerr rotation angle (θk) in a short wave band, etc., magnetooptic recording medium and a method of providing them. The magnetooptic thin film has an alloy composition is MnxSbyPtz, 45≦x≦56, 40≦y≦48, 2≦z≦15 and x+y+z=100 (where x, y and z are proportions in atomic %), and a ratio α/β of a diffraction intensity from a (220)-plane of a C1b type crystalline structure of the magnetooptic thin film in X-ray diffraction intensity β from a (110)-plane of a B81 type crystalline structure in from 0.05 to 1.0. The film thickness of the magnetooptic thin film is from 10 nm to 300 nm. The production method of the magnetooptic thin film is characterized in that the substrate, on which the magnetooptic thin film is to be formed, is heat-treated on a vacuum at most 5×10−6 Torr at a temperature not lower than 100° C. for at least 30 minutes before the thin film is formed.

Dependencies are inferred from the claim text.