Magneto - an optical recording medium, comprising a layer of high coercive force and a layer of low coercive force, which contains slight rare earths

摘要

PURPOSE:To facilitate recording and to improve coercive force, stability and reading- out characteristics by providing a high-coercive force layer consisting of an amorphous rare earth-iron group alloy and a low-coercive force layer consisting of an amorphous rare earth-iron group alloy contg. light rare earths subjected to exchange bonding therewith. CONSTITUTION:This magneto-optical recording medium is constituted of a transparent substrate 1, the low-coercive force layer 2 consisting of the amorphous rare earth-iron group alloy contg. the light rare earths, the high-coercive force layer 3 consisting of the amorphous rare earth-iron group alloy having the axis of easy magnetization in the direction perpendicular to the film plane and a protective layer 4 consisting of dielectrics such as SiO2 and Si3N4. The low-coercive force layer 2 and the high- coercive force layer 3 are exchange-bonded to each other. Recording is executed by previously magnetizing the magnetic layers 2, 3 in one direction, then scanning the same with a modulated laser beam while impressing a bias magnetic field in the reverse direction thereto from the outside. The part irradiated with the laser beam is magnetized in the direction reverse from the ambient by the effect of a bias magnetic field at the time when said part is once heated near to the Curie temp. of the layer 3 and is cooled.