Abstract: Provided is a magnetic domain wall displacement magneto-optical recording medium having a preferable reproducing signal characteristic. The magnetic domain wall displacement magneto-optical recording medium includes at least a magnetic domain wall displacement layer, a switching layer, and a recording layer, in which magnetic coupling between recording tracks is disconnected. An in-plane magnetized film layer is further provided adjacent to the surface of a recording layer opposite to a side of the recording layer facing the magnetic domain wall displacement layer.

Abstract: A method for manufacturing a magneto-optical recording medium in which reading of recorded information is performed through domain wall displacement in a reproduction layer is provided, in which magnetic separation of groove side-wall portions is performed more reliably; as a result a magneto-optical recording medium with satisfactory recording and reproduction characteristics can be provided.

Abstract: A plurality of types of recording pulse control rules for which the recording pulse waveform is determined according to the information signals to be recorded are stored in advance in an optical disk. When recording to the optical disk, information is recorded using a recording pulse where, due to the focused laser beam, the temperature in the recording layer cools more rapidly at a second information recording layer closer to the side where light is incident than at a first information recording layer farther away from the side where light is incident.

Abstract: In a magneto-optical recording medium, a first magnetic layer is made of a material using a Gd—Fe film or a Gd—Fe—Co film as a base so that a magnetic field normalized based on saturation magnetization of a magnetic domain wall driving field can be smaller than 1. A second magnetic layer is made of a material using a Tb—Fe film or a Dy—Fe film as a base, to which a nonmagnetic element such as Al or Cr, and Co are added. A third magnetic layer is made of a material using a Tb—Fe—Co film or a Dy—Fe—Co film as a base, and an element concentration ratio (at. % ratio) of Tb or Dy to Fe—Co is set in a range of 24.5?Tb?26.5 or 26.5?Dy?29.5. Addition amounts of Co and a nonmagnetic element to each magnetic layer are adjusted to set Curie temperatures Tc11, Tc12, and Tc13 of the first, second and third magnetic layers to Tc13>Tc11>Tc12.

Abstract: A magneto-optical recording medium includes a first magnetic layer (reproduction layer), a second magnetic layer (control layer), a third magnetic layer (blocking layer), and a fourth magnetic layer (recording layer) having respective Curie temperatures TC1, TC2, TC3 and TC4. The Curie temperatures of the layers satisfy the relationships TC1>TC3>TC2 and TC4>TC3. In addition, the magnetic anisotropy of the third magnetic layer Ku3 is greater than that of the second magnetic layer Ku2. A magnetic domain wall in the first magnetic layer in front of the spot irradiated by the reproduction light in the direction of travel is displaced toward the peak temperature portion so that a recorded domain is expanded. Displacement in the spot direction of a domain wall in the first magnetic layer behind the reproduction light spot in the direction of travel is suppressed. The second and third magnetic layers control the magnetic exchange coupling between the first and fourth magnetic layers.

Abstract: A magneto-optical recording medium includes at least a first magnetic layer, a second magnetic layer and a third magnetic layer which are layered in this order, the first magnetic layer being formed of a perpendicularly magnetized film having a relatively small wall coercivity and a relatively large wall mobility compared with the third magnetic layer in the vicinity of a predetermined temperature, and the magneto-optical recording medium satisfies conditions Tc2<Tcomp1<Tc1 and Tc2<Tcomp1<Tc3 where Tcomp1 is a compensation temperature of the first magnetic layer, Tc1, Tc2 and Tc3 are Curie temperatures of the first, second and third magnetic layers, respectively.

Abstract: A magneto-optical recording medium has a domain wall displacement layer, a recording layer for accumulating information and a switching layer arranged between said domain wall displacement layer and said recording layer and having a Curie temperature lower than those of the latter two layers. The domain wall displacement layer, the switching layer and the recording layer are coupled by exchange coupling at temperature not higher than the Curie temperature of the switching layer. The saturation magnetization of the domain wall displacement layer and the recording layer are in opposite directions to each other when the layers are coupled by exchange coupling at a temperature close to the Curie temperature of the switching layer.

Abstract: A magneto-optical recording medium includes a substrate and a reproducing layer and a recording layer provided on the substrate. A recording magnetic domain is provided in the recording layer by heating the recording layer by irradiation with light and applying a recording magnetic field to the recording layer so that information is recorded in the recording layer. The recording layer is a magnetic film having magnetic anisotropy in a direction perpendicular to the film surface, and the magnetic film holds the recording magnetic domain formed therein.

Abstract: A multilayer film including a first magnetic layer, a second magnetic layer, and a third magnetic layer in the stated order is formed so that a Curie temperature TC2 of the second magnetic layer is set to be lower than a Curie temperature TC1 of the first magnetic layer and a Curie temperature TC3 of the third magnetic layer and that the third magnetic layer is a perpendicular magnetization film. In at least a part of a region at a temperature lower than TC2, the first magnetic layer is perpendicularly magnetized by exchange coupling with the second magnetic layer, and the magnetization of the third magnetic layer is transferred to the first magnetic layer via the second magnetic layer because of the exchange coupling. The second magnetic layer is made of a magnetic layer that remains in an in-plane magnetization state at room temperature and is perpendicularly magnetized in a temperature range from a critical temperature TCR higher than room temperature to the Curie temperature TC2 of the same.

Abstract: A magneto-optical recording medium including a recording layer for recording information and a substrate for supporting the recording layer is disclosed. The recording layer includes: a recording magnetic film for recording the information, the recording magnetic film being formed of a perpendicular magnetic anisotropy film; and a readout magnetic film for optically reading out the information, the readout magnetic film being capable of being magnetically coupled with the recording magnetic film by an exchange-coupling force. The composition of the readout magnetic film may be chosen such that the exchange coupling force from the recording magnetic film does not affect the magnetization around the surface of the readout magnetic film on the side on which the readout light is incident.

Abstract: A magneto-optical recording medium including a magnetic recording layer for recording information and a magnetic reproducing layer provided on the magnetic recording layer for reading information. The magnetic reproducing layer is separated into a first reproducing layer having a first composition and a second reproducing layer having a second composition slightly different from the first composition. The first and second reproducing layers have the same principal components. By changing a ratio in film thickness between the first and second reproducing layers, variations in composition of the first and second reproducing layers can be corrected.

Abstract: Disclosed are magneto-optical recording media including at least a reflection layer, a recording layer and a dielectric layer laminated on a substrate in this order, wherein the thickness of the dielectric layer is not less than 140 nm or wherein the dielectric layer is provided by the lamination of upper dielectric layer and lower dielectric layer in which the thermal conductivity of the upper dielectric layer is higher than that of the lower dielectric layer. By arranging the thickness of the dielectric layer in a specific range, the surface roughness of a media in not more than 1.5 nm, and providing a reflection layer composed of a noble metal alloy, achieved is a magneto-optical recording medium able to record constantly in near-field magneto-optical recording, suitable for narrow track pitch, and having excellent SNR, resolution, and recording sensitivity.

Abstract: A magneto-optical recording medium comprising four magnetic layers including a mask layer, a reproduction layer, an intermediate layer and a recording layer, wherein the reproduction layer and the recording layer each have a direction of easy magnetization extending in a layer stacking direction at room temperature, the mask layer and the intermediate layer each have a direction of easy magnetization extending in an in-plane direction at room temperature, the mask layer, the reproduction layer, the intermediate layer and the recording layer have Curie temperatures Tc1, Tc2, Tc3 and Tc4, respectively, which satisfy relationships of Tc3<Tc2, Tc3<Tc4 and Tc3<Tc1, and the intermediate layer is a rare-earth-rich magnetic layer.

Abstract: A magneto-optical recording medium comprising four magnetic layers including a mask layer, a reproduction layer, an intermediate layer and a recording layer, wherein the reproduction layer and the recording layer each have a direction of easy magnetization extending in a layer stacking direction at room temperature, the mask layer and the intermediate layer each have a direction of easy magnetization extending in an in-plane direction at room temperature, the mask layer, the reproduction layer, the intermediate layer and the recording layer have Curie temperatures Tc1, Tc2, Tc3 and Tc4, respectively, which satisfy relationships of Tc3<Tc2, Tc3<Tc4 and Tc3<Tc1, and the intermediate layer is a rare-earth-rich magnetic layer.

Abstract: A magneto-optical recording medium for recording and reproducing carriers by laser beam irradiation includes a first magnetic layer which is magnetized in the in-plane direction at room temperature and is perpendicularly magnetized at a predetermined temperature T1 or more; a second magnetic layer which is in contact with the first magnetic layer, has a Curie temperature Tc2 higher than the predetermined temperature T1, and has in-plane magnetic anisotropy up to the Curie temperature Tc2; a third magnetic layer which has a Curie temperature Tc3 higher than the predetermined temperature T1 and has perpendicular magnetic anisotropy at least in a predetermined range of a temperature distribution of the magneto-optical recording medium during laser beam irradiation when reproducing; and a rare earth metal layer formed between the third magnetic layer and the second magnetic layer.

Abstract: A magnetic recording medium includes: a disk substrate; and a recording layer having magnetic anisotropy along a direction perpendicular to a surface of the disk substrate. The recording layer is formed so that a product of a coercive force Hc and saturated magnetization Ms of the recording layer (Ms·Hc) at room temperatures is increased sufficiently so that a shortest mark length of the recording layer can be decreased to a desired value.

Abstract: Featured is a magneto-optical storage medium including: a first magnetic layer constituted by a perpendicularly magnetized film; a second magnetic layer constituted by a perpendicularly magnetized film so as to be exchange coupled to the first magnetic layer; and a third magnetic layer magnetostatically coupled to the first and second magnetic layers at elevated temperatures, magnetization of the first magnetic layer being copied to the third magnetic layer. The second magnetic layer produces a greater peak net magnetization, has a higher Curie temperature than the first magnetic layer and produces a leaking magnetic flux. The structure enhances magnetostatic coupling forces acting between the first magnetic layer and the second magnetic layer and also between the first magnetic layer and the third magnetic layer.

Abstract: A magneto-optical storage medium includes: a reproduction magnetic layer exhibiting in-plane magnetization at room temperature and changing to perpendicular magnetization at a critical temperature or higher; first and second in-plane magnetized layers with Curie temperatures in a proximity of the critical temperature and exhibiting mutually opposite magnetic polarities; and a recording magnetic layer fabricated from a perpendicularly magnetized film, the reproduction magnetic layer, the first and second in-plane magnetized layers, and the recording magnetic layer being sequentially deposited, wherein the reproduction magnetic layer is exchange-coupled with the first and second in-plane magnetized layers at least at room temperature.

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.

Abstract: A magnetooptical recording medium comprising at least a reproduction layer, an intermediate layer, a connection layer and a recording layer, wherein the reproduction layer and intermediate layer have a slant magnetic direction in a non-magnetic field, and the connection layer is composed of a layer non-magnetic at room temperature by itself which is induced to exhibit magnetism by contact with a magnetic layer.

Abstract: At least a reproduction layer of a magneto-optical recording medium is formed by sputtering using a processing gas comprising Kr or Xe as a main component. Hence, it is possible to reduce the dependence of saturation magnetization MS on temperature, thereby decreasing the influence of a demagnetizing field and a floating magnetic field over a wide range of temperature.

Abstract: An MO disk includes a readout layer, an intermediate layer and a recording layer each of which is made of a rare earth-transition metal amorphous material. The MO disk also includes a fourth magnetic layer formed on the recording layer and made of a rare earth-transition metal amorphous magnetic material containing Gd. The fourth magnetic layer has a rare earth metal magnetization-dominant composition and an axis of easy magnetization oriented longitudinally at room temperature. The axis of easy magnetization is changed to be oriented perpendicularly to the fourth magnetic layer as the temperature of the fourth magnetic layer rises to the Curie temperature of the fourth magnetic layer.

Abstract: A magneto-optical recording medium includes a substrate and a reproducing layer and a recording layer provided on the substrate. A recording magnetic domain is provided in the recording layer by heating the recording layer by irradiation with light and applying a recording magnetic field to the recording layer in such a manner that information is recorded in the recording layer. The recording layer is a magnetic film having magnetic anisotropy in a direction perpendicular to the film surface, and the magnetic film holds the recording magnetic domain formed therein. The magneto-optical recording medium further comprises a intermediate layer and a reproducing aid layer between the reproducing layer and the recording layer. Saturated magnetization of the reproducing aid layer increases with an increase in the temperature of the reproducing aid layer.

Abstract: A magneto-optical recording medium includes a substrate and a reproducing layer and a recording layer provided on the substrate. A recording magnetic domain is provided in the recording layer by heating the recording layer by irradiation with light and applying a recording magnetic field to the recording layer in such a manner that information is recorded in the recording layer. The recording layer is a magnetic film having magnetic anisotropy in a direction perpendicular to the film surface, and the magnetic film holds the recording magnetic domain formed therein. The magneto-optical recording medium further comprises a intermediate layer and a reproducing aid layer between the reproducing layer and the recording layer. Saturated magnetization of the reproducing aid layer increases with an increase in the temperature of the reproducing aid layer.

Abstract: A magneto-optical recording medium has:

Abstract: A magneto-optical recording medium of the present invention has a recording layer made of a perpendicular magnetization film, and a readout layer which is in an in-plane magnetization state at room temperature and changes into a perpendicular magnetization state with a rise in temperature. When the magneto-optical recording medium is irradiated with a light beam, the readout layer separates into three regions: a region in an in-plane magnetization state, a region in a perpendicular magnetization state, and a region having a temperature not lower than the Curie temperature thereof. Only the region in the perpendicular magnetization state allows copying of the magnetization of the recording layer. Therefore, even when the diameter and intervals of recording bits on the recording layer are very small, it is possible to reproduce a target recording bit separately from a recording bit adjacent to the target recording bit.

Abstract: A magneto-optical storage medium that protects against the effects of cross-talk, making it possible to further reduce the level of track density, and which also makes it possible to conduct high-density recording/playback with a reduced magnetic field for erasure and a favorable level of playback signal quality. More specifically, a magneto-optical storage medium, which includes at least the following laminated layers, in the following order: a playback layer, a non-magnetic layer, a transfer layer, a cut-off layer, and a recording layer. The playback layer preferably displays easy in-plane magnetization characteristics within the monolayer at room temperature, and the transfer layer and the recording layer each have easy magnetization characteristics in the vertical direction of the monolayers at room temperature when each layer is considered as a monolayer.

Abstract: A reproducing layer having perpendicular magnetization in a single layer, an in-plane magnetic layer, and a recording layer having perpendicular magnetization are formed in this order. When the reproducing layer, the in-plane magnetic layer, and the recording layer have the Curie temperatures of Tc1, Tc2, and Tc3, these values satisfy conditions of Tc2<Tc1 and Tc2<Tc3. The reproducing layer has in-plane magnetization due to an exchange coupling with the in-plane magnetic layer at lower than Tc2. At Tc2 or higher, magnetization information is expanded and transferred from the recording layer to the reproducing layer, so that the reproducing layer has single-domain perpendicular magnetization.

Abstract: Recorded information is reproduced based on the displacement of a domain wall using an optical system having a reproducing optical beam with the beam waist diameter thereof satisfying a condition of 2 Wo<900 nm. A sharp temperature distribution is formed in the recording medium, and the speed of displacement of the magnetic wall is increased. Even when a disk rotational speed is increased, a reliable domain wall displacement reproduction is thus accomplished.

Abstract: A magnetooptical recording medium has a first magnetic layer which is an in-plane magnetization film at both room temperature and high temperatures and changed to a perpendicular magnetization film at intermediate temperatures, and a second magnetic layer which is composed of a perpendicular magnetization film. The recording medium enables realization of high S/N reproduction of information recorded at a pitch below the diffraction limit of light with a simple structure, and further improvement in linear recording density and track density.