| 摘要 |
PURPOSE:To obtain a photomagnetic disk having a large Kerr revolving angle with a simple layer structure and improved S/N for by providing successively a protecting oxide film, metallic reflecting film, photomagnetic recording medium film and a substrate from the incident direction of a laser light beam. CONSTITUTION:A photomagnetic disk film contains a protecting oxide film (SiO film, etc.) 6, metallic reflecting film 7, photomagnetic recording medium film 8 and a transparent glass substrate 9 in order from the incident direction of a laser light beam. Especially the film 7 is formed with Cu and Au or Ag and Al of 80-120Angstrom thickness. The film 8 is formed with GdTbFe, etc. with about 150Angstrom thickness. In such a way, one part of the incident laesr light is reflected by the film 7 and comes back; while the other part of light transmits through the film 7 and 3, and then films 7 and 6 after reflected twice by the film 8 and then comes back. As a result, the magnetic Kerr effet is increased about 1.7 times compared with just in case of a single film 8. In such a way, the manufacturing process is simplified with reduction of the number layers and furthermore the S/N is improved to obtain a photomagnetic disk having excellent performance. |
