| 摘要 |
PURPOSE:To obtain a substrate for a photomagnetic disc which is highly mechanically strong and is thermally stable by forming an SiO2 layer and an a-SiO layer respectively to prescribed thicknesses on a metallic substrate. CONSTITUTION:A substrate for a photomagnetic disc which is highly mechanically strong and is thermally stable is obtd. by forming an SiO2 film 2 having >=1,200Angstrom film thickness and an a-SiO film 1 having >=500Angstrom film thickness on an Al disc 3. A Gd20Tb7Fe73 film is formed on the film 1 of such substrate to 1.2mum thickness, by which the photomagnetic disc is obtd. |
