| 摘要 |
PURPOSE:To efficiently perform magnetic recording and reproduction without containing by coating a transparent film with less light reflection on a magnetic thin film having vertical magnetic isotropy consisting essentially of a cobalt containing 10-20wt% chromium, and chromium. CONSTITUTION:A high magnetic substance layer 2' made of ''Permalloy '' is provided on a substrate 1 made of glass and ceramic etc., a vertical magnetic thin film 2 consisting essentially of Cr and Co containing 10-20wt% Cr is provided on the layer 2', and a transparent protective film 3 with less light reflection factor is provided on the film 2. In reading the information recorded on the magnetic thin film, a laser light is irradiated on the thin film 2 with linear-polarization through a polarizer 11, a mirror 12 and a lens 13 from a heat ray source 10, and the reflection light is inputted to a photodetector 14 and a photoelectric converter 15. The amount of rotation of the polarized wave due to the Kerr effect produced at the photodetector 14. Thus, the signal can be reproduced efficiently without contacting. |
