Patent ID: 7092318

Claim:
A magneto-optical recording medium having multiple magnetic layers comprising: a first magnetic layer; a second magnetic layer; and a third magnetic layer, the first to third magnetic layers being sequentially formed from a side irradiated with a laser beam, during recording, an information signal being recorded in a form of a magnetic domain in the third magnetic layer having an easy magnetization axis in a vertical direction by an external magnetic field while the laser beam irradiation is executed, then the magnetic domain being exchanged through the second magnetic layer with the first magnetic layer and, during reproducing, magnetization of the second magnetic layer being lost by a temperature raised by the laser beam irradiation, and magnetic domain wall displacement being generated to enlarge the magnetic domain formed by the exchange coupling in the first magnetic layer, wherein the first magnetic layer is formed by using a material with a base of a Gd—Fe film or a Gd—Fe—Co film in order to set a normalized magnetic field obtained by normalizing a magnetic domain wall driving field based on saturation magnetization higher than 1, an element concentration ratio (at. % ratio) of Gd to one of Fe and Fe—Co is set in a range of 28.0≦Gd≦29.0, the second magnetic layer is formed by using a material with a base of a Tb—Fe film or a Dy—Fe film, and adding at least one of Co, Al and Cr, the third magnetic layer is formed by using a material with a base of one of a Tb—Fe—Co film and a Dy—Fe—Co film, an element concentration ratio (at. % ratio) of one of Tb and Dy to Fe—Co is set in a range of one of 23.5≦Tb≦25.5 and 25.5≦5 Dy≦28.5, and addition amounts of Co and a nonmagnetic element to each magnetic layer are adjusted to set Curie temperatures Tc 11 , Tc 12 , and Tc 13 of the first, second and third magnetic layers to Tc 13 ≦Tc 11 ≦Tc 12 .