Magneto-optical recording medium and reproducing method for the same

A magneto-optical recording medium, comprising:

• a substrate;
• a first recording magnetic layer for storing data therein in the form of discrete directional magnetizaton, the first magnetic layer being rare earth-transition metal alloy;
• a second reproducing magnetic layer for reproducing said data recorded in the first magnetic layer by aligning in accordance with a discrete directional magnetization of said recording layer through an exchange-coupled force induced at a reproduction temperature under the influence of a bias magnetic field, the second magnetic layer being rare earth-transition metal alloy;
• a third magnetic layer for controlling recording and erasing of data to and from the first magnetic layer;
• a fourth ragnetic layer for holding a magnetization direction of said recording layer during a data erasure operation;
• and
• an intermediate layer formed of material which is in a an antiferromagnetic state at said reproduction temperature, said intermediate layer being between the first and second magnetic layers and limiting the exchange-coupled force therebetween,
• wherein the intermediate layer has a N.epsilon.el temperature higher than said reproduction temperature.

A magneto-optical disk drive apparatus comprsing:

• a magneto optical recording medium,
• means for recording information on said recording medium, and
• means for reproducing the recorded information from the recording medium,
• said recording medium having
• a substrate,
• a first magnetic layer and a second magnetic layer formed on said substrate, said first and second magnetic layers being magnetically coupled to each other through an exchange-coupled force whereby data in said second layer is aligned as a copy of data in said fist layer to permit reproduction of data stored in said first layer, said first and second magnetic layers being rare earth-transition metal alloy;
• and
• an intermediate layer formed of material which is in an antiferromagnetic state at a reproduction temperature, said intermediate layer being between said first and second magnetic layers and limiting the exchange-coupled force therebetween so as to obtain an optimum exchanged-coupled force;
• wherein said intermediate layer has a N.epsilon.el temperature higher than said reproduction temperature.

A magneto-optical disk drive apparatus comprising:

• a magneto optical recording medium,
• means for recording information on said recording medium, and
• means for reproducing the recorded information from said recording medium at a reproducing temperature,
• said recording medium having
• a substrate;
• a first recording magnetic layer for storing data therein in the form of discrete directional magnetization, the first magnetic layer being a rare earth-transition metal alloy;
• a second reproducing magnetic layer for reproducing said data recorded in said first magnetic layer by aligning in accordance with a discrete directional magnetization of said recording layer through an exchange-coupled force induced at a reproduction temperature under the influence of a bias magnetic field, said second magnetic layer being a rare earth-transition metal alloy;
• a third magnetic layer for controlling recording and erasing of data to and from said first magnetic layer;
• a fourth magnetic layer for holding a magnetization direction of said recording layer during a data erasure operation;
• and
• an intermediate layer formed of material which is in an antiferromagnetic state at said reproducing temperature, said intermediate layer being between said first and second magnetic layers and limiting the exchange-coupled force therebetween,
• wherein said intermediate layer has a N.epsilon.el temperature higher than said reproducing temperature.