| 摘要 |
(1) The present invention adopts as the basic structure of its thermomagnetic recording medium an arrangement consisting of a first and a second magnetic thin film having perpendicular anisotropy and a third magnetic thin film having in-plane magnetic anisotropy or small perpendicular magnetic anisotropy interposed therebetween, formed into a laminated structure by being magnetically coupled to the adjoining films in turn, modulates and switches, in accordance with information to be recorded, a first heating condition and a second heating condition, with the medium applied with a predetermined external magnetic field Hex in the direction perpendicular to the plane of the film, the first condition being that for raising temperature of the medium to a first temperature T1 which is virtually above the Curie temperature TCl of the first magnetic thin film and not causing reversal of the magnetic moment in the second magnetic thin film and the second condition being that for raising temperature of the same to a second temperature T2 which is virtually above the Curie temperature TCl and sufficient to cause reversal of the magnetic moment in the second magnetic thin film, (2) to thereby form an information bit (magnetic domains) in the first magnetic thin film, and adapts during the course the medium is cooled from the heated states such that two states established by the different relationships between the directions of magnetization of the first and second magnetic thin films are finally formed whereby the recording of the information is performed, and thus the present invention brings about conditions enabling alteration of recorded information to other information, that is, enabling so-called overwriting. Especially, by virtue of the third magnetic thin film, the present invention achieves simplification of the apparatus for applying the magnetic field.
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