MAGNETO-OPTICAL RECORDING MEDIUM

摘要

PURPOSE: To attain superior quality of a reproduced signal by setting the magnitude of an applied magnetic field required at the time of reproduction in accordance with the coercive force, film thickness and saturation magnetization of a reproducing layer and magnetic domain wall energy accumulated in the interface between the reproducing layer and a recording layer. CONSTITUTION: A rare earth element-transition metal alloy layer of GdFeCo having 180 deg.C compensation temp. and 330 deg.C Curie temp. is used as a reproducing layer 3 and the thickness is regulated to 50nm. A rare earth element-transition metal alloy layer of DyFeCo having a compensation temp. of room temp. and 240 deg.C Curie temp. is used as a recording layer 5 and the thickness is regulated to 50nm. The thickness of an AlN dielectric film 2 is 70nm and that of an AlN dielectric film 6 is 50nm. A GdFeCo film having 20nm thickness is interposed as a middle layer. Magnetic domain wall energyσw between the reproducing layer and the recording layer at room temp. is varied by varying the magnitude of the perpendicular magnetic anisotropic energy (Ku) of the middle layer and the objective disk is obtd.