Magneto-optical recording medium capable of double mask readout

Abstract

A magneto-optical recording medium of a three-layered structure (consisting of a readout layer, an intermediate layer, and a recording layer), capable of double-mask magnetically-induced super-resolution readout, has magnetic properties such that the exchange coupled force between the readout layer (a GdFeCo film) and the intermediate layer (a GdFe film) decrease with increasing temperature, while the exchange coupled force between the intermediate layer and the recording layer (a TbFeCo film) increase with increasing temperature. The magnetic property of the readout layer is transition-metal magnetization dominant, and that of the intermediate layer is rare-earth magnetization dominant. When reading the medium, a region (an intermediate-temperature transfer region) where the magnetization in the readout layer is oriented in the direction of magnetization in the recording layer, and a region (a high-temperature rear mask) where the magnetization in the readout layer is oriented in a second specific direction, are simultaneously formed within a beam spot from a state (a low-temperature front mask) in which the magnetization in the readout layer is oriented in a first specific direction, thus achieving a double mask condition in a single step. Overwrite recording and magnetically-induced super-resolution readout are realized on the same magneto-optical recording medium.