Thermomagnetic recording method applying power modulated laser on a magnetically coupled double layer structure of perpendicular anisotropy film

摘要

Thermomagnetic recording method using a thermomagnetic recording medium having a superposed layer of magnetically coupled first and second magnetic thin films is disclosed. The magnetic thin film includes a portion where the respective magnetic moments of the first and second thin films are coupled in opposite directions to each other. The method comprises heating the superposed layer in a first heating state in which the superposed layer is heated at a temperature T1 which is higher than the Curie temperature TC1 of the first magnetic thin film and will not cause the inversion of the magnetic moment of the second magnetic thin film or in a second heating state in which the superimposed layer is heated at a temperature T2 which is higher than the Curie temperature TC1 and is high enough to cause the inversion of the magnetic moment of the second magnetic thin film by modulating heating condition according to an information signal to be recorded; and forming recording magnetization on the thermomagnetic recording medium by cooling the heated superimposed layer of the thermomagnetic recording medium. In the method, real-time overwriting information can be achieved without using a modulated external magnetic field.