Magneto-optical recording medium and reproduction method therefor

Abstract

A magneto-optical recording medium comprises, on a substrate, a dielectric layer, a GdFeCo reproducing layer, a non-magnetic layer, and a TbFeCo recording layer. Upon reproduction, a DC magnetic field Hex is applied in the recording direction, and a reproducing light beam is radiated while being modulated to have a low power and a high power in synchronization with a reproducing clock. The reproducing layer is a magnetic film which changes from in-plane magnetization into perpendicular magnetization at a critical temperature Tcr, which has a compensation temperature Tcomp between room temperature and a Curie temperature Tc, and which satisfies Troom<Tcr<Tcomp<Tco<Tc in relation to a Curie temperature Tco of the recording layer. Magnetic domain transfer and magnetic domain magnification occur if the transfer magnetic field of the recording layer and the coercive force of the reproducing layer have the relationship of relative magnitude as shown in FIG. in temperature areas (a) and (b) when the reproducing light beam having the low power is radiated. The magnified magnetic domain is reliably extinguished if the transfer magnetic field of the recording layer and the coercive force of the reproducing layer have the relationship of relative magnitude as shown in FIG. in a temperature area (c) when the reproducing light beam having the high power is radiated. A minute magnetic domain, which is smaller than the reproducing light spot on the magneto-optical recording medium, can be subjected to reproduction independently to produce an amplified reproduced signal.