| 摘要 |
PURPOSE:To obtain a disk having an increased Kerr revolving angle by forming successively a photomagnetic recoding medium film, dielectric heat insulating film, photomagnetic recording medium film, metallic reflecting film and a dielectric protecting film on a transparent substrate and setting the thickness of each film within a specific range excepting the projecting film. CONSTITUTION:A photomagnetic recording medium film 12 is formed with GdTbFe, for example, on a transparent substrate 11 with 50-180Angstrom thickness. Then, a heat insulating film 13 is formed with SiO2, etc. with <=1,000Angstrom , and the 2nd photomagnetic recording medium film 14 is formed on the film 13 with 50- 250Angstrom . A metallic reflecting film 15 is formed with Cu, etc. on the film 14 with >=200Angstrom . Finally a protecting film 16 of O, etc. is formed on the film 15. Thus a photomagnetic disk is obtained. The film 15 is formed with a double-layer medium film (12, 13), and therefore the magnetic Kerr effect is increased about 4.7 times as much as a single-layer medium film. In such a way the S/N of reproduction is improves greatly. |
