PHOTOTHERMOMAGNETIC RECORDING MEDIUM PROTECTED BY GEN

• Main Author: KIMURA FUMITO
• Format: Patent
• Language: English
• Published: 11.01.1986
• Subjects: INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; PHYSICS; STATIC STORES

PURPOSE:To improve the durability of photothermomagnetic recording medium composed of a base board and vertically magnetized film, by providing a GeN layer on at least one of both surfaces of the vertically magnetized film. CONSTITUTION:A photothermomagnetic recording medium is composed of a base board and vertically magnetized film. In this case, a GeN layer is provided on at least one of both surfaces of the vertically magnetized film. Namely, the GeN layer having a thickness of about 650Angstrom is formed on a glass base board by sputtering at a film forming speed of about 130Angstrom /min by using a Ge target. The photothermomagnetic recording medium can be manufactured also by using an SiO2 film instead of the GeN film, with the other processes being performed in the same way as the embodiment. When the recording medium manufactured in such a way is put in an atmosphere with 70 deg.C temperature and 80% moisture and the coercive force Hc of the vertically magnetized film is measured in the lapse of time, and then, the variation of the coercive force is compared by dividing the measured coersive force Hc by the coercive force H6 before testing, the result shown in the figure is obtained. It is obvious that the photothermomagnetic recording medium using GeN film is more durable than that using SiO2 film from the result shown in the figure.