PURPOSE: To lessen the unerasing in overwriting by previously magnetizing magneto- optical recording films in such a manner that the directions of the axes of easy magnetization are different from each other and irradiating these films with laser beams from the outside to change the axes of easy magnetization, thereby executing recording and erasing.
CONSTITUTION: Two layers of the magnetic films are formed with a TbFeCoNb film 3 having 150 to 240°C Curie temp. and relatively large coercive force and a GdTbFeCoNb film 4 having 270 to 350°C Curie temp. and the coercive force smaller by ≥2kOe than the coercive force of the film 3. The film 3 is heated up to the Curie temp. with a lower laser power and the recording is executed by transferring the direction of the magnetization of the film 4 in the process of cooling at the time of recording. Both of the films 3, 4 are heated up to the Curie temp. by using the light of a high power and are magnetized in the directions of the externally impressed magnetic field in the cooling process at the time of erasing. The recording medium is thereafter passed in the initializing magnetic field and the original film 4 is returned to the original direction. Then, since the erasing power is higher than the recording power, the unerasing does not arise.
MAEDA TAKESHI
NAKAO TAKESHI
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