Patent ID: 7522479

Claim:
A magnetic domain wall displacement magneto-optical recording medium, comprising: a substrate; a magnetic layer formed on the substrate, the magnetic layer including a least a first magnetic layer in which a magnetic domain wall displaces, a second magnetic layer, and a third magnetic layer for holding a recording magnetic domain according to information, wherein the second magnetic layer is located between the first magnetic layer and the third magnetic layer and has a Curie temperature lower than Curie temperatures of the first magnetic layer and the third magnetic layer; a plurality of recording tracks formed on the magnetic layer; a magnetic disconnecting area for disconnecting magnetic coupling between the recording tracks; and a fourth magnetic layer which is formed on an opposite side to the second magnetic layer with respect to the third magnetic layer and shows an in-plane magnetized state in a range from room temperature to a Curie temperature of the fourth magnetic layer, wherein the Curie temperature of the fourth magnetic layer is lower than the Curie temperature of the third magnetic layer; wherein at least the third magnetic layer and the fourth magnetic layer are exchange-coupled to each other in a range from the room temperature to the Curie temperature of the fourth magnetic layer; and wherein in a temperature range from a vicinity of the Curie temperature of the second magnetic layer which is a magnetic domain wall displacement start temperature of the first magnetic layer to a maximum temperature of a spot for reproduction which is a magnetic domain wall displacement end temperature, total saturation magnetization of stacked layers composed of at least the fourth magnetic layer, the first magnetic layer, the second magnetic layer and the third magnetic layer is smaller than total saturation magnetization of stacked layers composed of at least the first magnetic layer, the second magnetic layer and the third magnetic layer.