Abstract: A data storage device using magnetic domain wall motion may include a first magnetic layer having a plurality of magnetic domains. A second magnetic layer may be connected to the first magnetic layer, and a connection layer may be disposed between the first and second magnetic layers. A resistive magnetic layer may be disposed between each of the first and second magnetic layers and the connection layer. Accordingly, when current is supplied to the data storage device to move a magnetic domain wall, the leakage of current in a connection between the magnetic layers may be reduced or prevented, thus conserving power.

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 recording/reproducing apparatus for a domain-wall-displacement magneto-optical recording medium with good format efficiency, capable of providing a good reproduction signal and securing a maximum recording region for a user is provided which comprises a recording circuit that starts recording of an information in a data region at a predetermined timing with a detection signal obtained in the preformat region being used as a reference, and a reproducing circuit that starts reproducing of the information recorded in the data region at a timing earlier than the predetermined timing with the detection signal being used-as a reference.

Abstract: It is an object of the present invention to provide a magneto-optical recording medium including a recording film having at least a reproduction layer, an intermediate layer, and a recording layer, on an optical disk substrate, wherein the recording film is a magnetic film that is magnetically coupled and that has magnetic anisotropy in a direction vertical to its film surface, the recording magnetic domains formed in the recording layer are transferred to the reproduction layer, and recording information is reproduced by domain wall movement in the reproduction layer, and the recording layer has columnar structures that are oriented substantially vertically.

Abstract: A domain-wall-displacement-type magnetooptical recording medium is provided in which a floating magnetic field from a surrounding portion that operates on a recording/reproducing portion is suppressed. The recording medium includes a displacement layer having a composition such that rare-earth-element sub-lattice magnetization is dominant at room temperature, a switching layer, a memory layer, and a magnetization compensation layer in which iron-family-element sub-lattice magnetization is dominant at room temperature, for suppressing generation of a stray magnetic field at a temperature near room temperature.

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: According to the present invention, a light beam is radiated to an area between recording tracks while the intensity of a magnetic field from the outside to a magneto-optical recording medium is suppressed to 50 Oe or less, whereby magnetic anisotropy formed between the recording tracks is set to be lower than that of the magnetic layer on the recording tracks, and micro-domains, for example, having a diameter smaller than a half-width of a light beam for reproduction in a film surface direction are formed on recording tracks. Because of this method, the influence of a leakage magnetic field in the magneto-optical recording medium adopting a DWDD reproducing system is alleviated.

Abstract: An information recording/reproducing apparatus for recording and reproducing information to and from a magneto-optical storage medium that includes a first magnetic layer for recording at least information, a second magnetic layer for regulating a switched connective force, and a third magnetic layer for shifting a magnetic wall of recorded markings for information reproduction. The three layers being stacked on a transparent substrate to make up the storage medium. The information recording/reproducing apparatus includes an optical head and a magnetic head. The optical head has a light source and an objective lens, the light source is configured to emit at least a laser beam with a wavelength of about 780 nm, the objective lens having a numerical aperture of about 0.45 and is configured to focus the laser beam from the light source into a beam spot for emission onto the magneto-optical storage medium. The magnetic head is for applying a recording magnetic field to the magneto-optical storage medium.

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: The present invention provides a method of recording information on a magneto-optical recording medium of domain wall displacement type having a preformat area and a data area succeeding thereto, comprising the steps of generating a reproduction signal from said medium by utilizing a light beam, detecting a reference position based on said reproduction signal, determining, based on a result of the detection, a recording start timing at which a formation of a recording magnetic domain is started at a distance at least not shorter than a displacement amount of a domain wall away from a start position of said data area; and starting a recording with said determined recording start timing.

Abstract: A recording and reproduction apparatus using a plurality of generations of optical recording media and an optical recording medium used in such a recording and reproduction apparatus, wherein the optical recording medium comprises first and second recording areas, the first recording area is divided into a plurality of zones, each of the plurality of zones is divided into a plurality of divided areas of one type among a plurality of types set in advance, the plurality of divided areas are assigned addresses and have fixed recording capacities, and identification information indicating the one type is recorded in the second recording area. The apparatus focuses a laser beam on the second recording area to read the identification information and records information on the first recording area or detects recorded information of the first recording area based on the identification information. The optical recording medium is for example a magneto-optical disk.

Abstract: There is provided a domain wall displacement type magneto-optical recording medium and a recording method that allow signals recorded with a high density over the limit of resolution of optical systems to be regenerated without increasing complexity of a recording and regenerating apparatus or narrowing an operation margin even if a substrate having address information or the like incorporated therein is used. An information track has portions used for recording and regenerating information in the form of a magneto-optical signal and portions having irregularities to provide address information or servo information formed therein alternately arranged, and directions of magnetization of the third magnetic layer are polarized in one direction above the portions having the irregularities.

Abstract: A recording and reproduction apparatus using a plurality of generations of optical recording media and an optical recording medium used in such a recording and reproduction apparatus, wherein the optical recording medium comprises first and second recording areas, the first recording area is divided into a plurality of zones, each of the plurality of zones is divided into a plurality of divided areas of one type among a plurality of types set in advance, the plurality of divided areas are assigned addresses and have fixed recording capacities, and identification information indicating the one type is recorded in the second recording area. The apparatus focuses a laser beam on the second recording area to read the identification information and records information on the first recording area or detects recorded information of the first recording area based on the identification information. The optical recording medium is for example a magneto-optical disk.

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 recording and reproduction apparatus using a plurality of generations of optical recording media and an optical recording medium used in such a recording and reproduction apparatus, wherein the optical recording medium comprises first and second recording areas, the first recording area is divided into a plurality of zones, each of the plurality of zones is divided into a plurality of divided areas of one type among a plurality of types set in advance, the plurality of divided areas are assigned addresses and have fixed recording capacities, and identification information indicating the one type is recorded in the second recording area. The apparatus focuses a laser beam on the second recording area to read the identification information and records information on the first recording area or detects recorded information of the first recording area based on the identification information. The optical recording medium is for example a magneto-optical disk.

Abstract: A magneto-optical recording medium wherein a magnetic domain is transferred from a recording layer to a reproducing layer is expanded. When the reproducing layer is formed, the composition ratio of a transition metal at a surface of the reproducing layer on a reproducing light beam-incoming side is made to be higher than the composition ratio of the transition metal at a surface of the reproducing layer on a side opposite to the reproducing light beam-incoming side. Thus, the operation to expand the magnetic domain, transferred from the recording layer to the reproducing layer, is performed smoothly, and the jitter of the reproduced signal is reduced to improve signal-to-noise ratio (S/N) of the reproduced signal.

Abstract: The present invention is a magneto-optical disk adopting the magnetic domain wall displacement detection type ultra-high resolution playback method. The magneto-optical disk has a recording track whose width Tw given as Tw≦0.046×(&lgr;/NA), where &lgr; is a wavelength of a laser light which is irradiated to a magneto-optical disk to play back recorded signals recorded on the magneto-optical disk and NA is a numerical aperture. Thus, the detrack tolerance can be 160 nmpp or more, which is contributed to easier design of the disk drive tracking.

Abstract: A magneto-optical medium of a domain wall displacement type is provided which does not cause inward leakage of signals caused by domain wall displacement from the rear of a reproducing light spot. The magneto-optical medium comprises a domain wall displacement layer, a switching layer, and a memory layer. The switching layer has a boundary temperature higher than room temperature for transformation from a state of a perpendicular magnetization film to a state of an in-plane magnetization film.

Abstract: On a disk-shaped substrate with pits and grooves, a first dielectric layer, a magnetic layer, and a second dielectric layer are formed. A data region used for recording/reproduction includes a plurality of tracks, and is divided into a plurality of segments. Each segment includes a pit region and a groove region. Recording/reproducing tracks are composed of the grooves. Magnetic anisotropy of a magnetic layer positioned on each of lands between the respective recording/reproducing tracks is reduced to a level lower than that of magnetic anisotropy of the magnetic layers positioned on the grooves, so that the recording/reproducing tracks are magnetically separated. On an inner side of an innermost recording/reproducing track and on an outer side of an outermost recording/reproducing track, at least one dummy track is provided, respectively.

Abstract: Provided is a magneto-optical recording medium capable of accurately reproducing a signal of a recording density exceeding a resolution of an optical system without making a constitution thereof complicated. The magnetic domain wall displacement type magneto-optical recording medium, comprises: a magnetic domain wall displacement layer in which a magnetic domain wall moves to contribute to information reproduction; a memory layer holding a recorded magnetic domain corresponding to the information; and a switching layer which is arranged between the magnetic domain wall displacement layer and the memory layer and has a Curie temperature lower than Curie temperatures of the magnetic domain wall displacement layer and the memory layer.

Abstract: By irradiating a light beam between recording tracks of the magneto-optical recording medium, the magnetic anisotropy of at least one layer selected from the group consisting of the domain wall displacement layer and the recording layer formed between the recording tracks can be made lower than that of said layers on the recording tracks, and a bias magnetic field is applied at least between recording tracks while a light beam is radiated. Because of this, initialization of a medium may be conducted simultaneously.

Abstract: Two-dimensionally annular or spiral lands and grooves are formed in a magneto-optical disk having a magnetic layer composed of a magnetic domain wall displacement layer, a switching layer, and a record retaining layer. The lands and the grooves are each used as a recording and reproducing area. A side wall present between the land and the groove and its vicinity are annealed so as to change the physical properties of these areas. The width of the land is larger than the width of the groove by 0.5 to 4 times the width of the side wall. Further, the ratio of the width of the land to the width of the groove is 1.05 to 1.20. Furthermore, the grooves have a period of 1.0 to 1.2 microns.

Abstract: As a magneto-optical recording medium capable of obtaining stable tracking servo signals with a narrow tracking pitch with less influences of cross talk and cross write, a magneto-optical recording medium is provided which comprises a plurality of recording/reproducing tracks and wobble pits for a sample servo, wherein each of the wobble pits is provided between two adjacent tracks and used commonly by the adjacent tracks.

Abstract: There are provided a magneto-optical recording medium in which domain-wall-displacement without affection by a wobbling shape is performed stably in a recording track region and which enables recording and reproduction of an information to be performed in a stable manner, and a method of producing the magneto-optical recording medium. The domain-wall-displacement type magneto-optical recording medium comprises a substrate having formed therein a groove and a land at least either of which is used as a recording track for an information, the recording track being wobbled to indicate an address information; a magnetic layer formed on the substrate; and an annealed region formed by annealing the magnetic layer between the recording tracks, wherein the annealed region is formed linearly along the wobbled recording track.

Abstract: A magneto-optic recording medium in which information is reproduced while a recording magnetic domain is enlarged by displacing a domain wall based on a temperature distribution formed by a beam of light and having a maximum temperature Tr. The recording medium comprises a reproducing layer in which a domain wall is displaced, a recording layer for holding a recording magnetic domain corresponding to information, and a cutoff layer disposed between the reproducing layer and the recording layer and having a Curie temperature lower than those of the reproducing layer and recording layer. The recording medium satisfies the following condition; (Tr−RT)/(Tc2−RT)≧1.8 where Tc2: Curie temperature of the cutoff layer, and RT: room temperature.

Abstract: A high density optical information recording medium comprises a substrate having rows of land and groove and a recording layer formed on the substrate. Each of the rows of land or groove includes at least two recording tracks separated by a denatured region produced by irradiating e.g. the center of each row in the recording layer with a denaturing light beam accompanied with one or two sub-beams for tracking control. Recording and reproduction of information can be performed likewise by using a recording or reproduction light beam accompanied with one or two tracking sub-beams.

Abstract: A magneto-optical recording medium has magneto-optical recording layers (11, 12, 13) and reproducing layers (21, 22, 23). The information recorded in the reproducing layers are reproduced by means of reproducing light beams (31, 32, 33) of different wavelengths, respectively. In reproduction, magnetic domains (4) recorded in the recording layers are transferred in the reproducing layers formed on the respective recording layers, the transferred magnetic domains (5) are enlarged with an external magnetic field, and the information is reproduced. Since information is recorded and reproduced for each recording layer, the recording density is improved. Further since the reproduction signals are amplified by the magnetic domain enlargement, the C/N is improved.

Abstract: A magnetic layer having a third magnetic layer in which information is recorded and a first magnetic layer for regenerating information recorded in the third magnetic layer by displacing a magnetic domain wall is stacked on a substrate via first and second underlying layers to produce a magneto-optical recording medium. The second underlying layer adjacent to the first magnetic layer, and the first underlying layer is adjacent to the second underlying layer and on the side of the substrate. The first underlying layer and the second underlying layer have different densities.

Abstract: The present invention is a method of reading and writing in MAMMOS that uses the edge of the thermal profile for detection of a domain rather than using the tip of the profile. By using the edge, it is possible to detect the position of domains rather than merely the presence of domains. Thus, domain positions are used to store data. By measuring these positions relative to the last domain, more accuracy can be gained. The new scheme is called Domain Position Detection for MAMMOS (DPD-MAMMOS). In DPD-MAMMOS, the information is encoded into the MAMMOS media in the form of the position of the domains rather than the presence of the domains. In this way, each domain stored in the media can contain several bits or possibly bytes of information. Methods of reading and writing information are disclosed.

Abstract: A domain wall displacement type magneto-optical recording medium is provided that can perform stable domain wall movement and prevent cross-write while adopting the land/groove recording to attain a narrow track pitch.

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 information recording/reproducing apparatus for recording and reproducing information to and from a magneto-optical storage medium that includes a first magnetic layer for recording at least information, a second magnetic layer for regulating a switched connective force, and a third magnetic layer for shifting a magnetic wall of recorded markings for information reproduction. The three layers being stacked on a transparent substrate to make up the storage medium. The information recording/reproducing apparatus includes an optical head and a magnetic head. The optical head has a light source and an objective lens, the light source is configured to emit at least a laser beam with a wavelength of about 780 nm, the objective lens having a numerical aperture of about 0.45 and is configured to focus the laser beam from the light source into a beam spot for emission onto the magneto-optical storage medium. The magnetic head is for applying a recording magnetic field to the magneto-optical storage medium.

Abstract: To provide an information recording method, an information recording apparatus and an information reproducing method and an apparatus for a domain wall mobile type magneto-optical medium. In the information recording method, a light beam scans on the medium for heating and at the same time a magnetic field modulated corresponding to the information is applied to a heated point, and a recording magnetic domain having an arc shaped magnetic domain wall bending convex in a forward direction of an operation of the light beam is formed so that the information is recorded. The information recording apparatus, includes an optical head to radiate the light beam for executing the information, a magnetic head to generate a magnetic field modulated corresponding to the information, and a unit for causing the optical head, the magnetic head and the medium to relatively move.

Abstract: A magneto optical recording medium capable of stable recording and readout using a DWDD system is provided. The magneto optical recording medium of the present invention comprises an optical disk substrate and a multilayer recording film comprising essentially a readout layer, an intermediate layer, and a recording layer successively formed on top of the substrate. The readout layer has a smaller magnetic domain wall coercivity than the recording layer. The intermediate layer comprises a magnetic layer whose Curie temperature is lower than the readout layer and the recording layer. A recorded/readout magnetic domain corresponding to recorded/readout information is formed only in a groove area of the optical disk substrate. The thickness of the recording film at the boundary between mutually adjacent recording track areas is smaller than the thickness of the recording film in the center portions of the recording track areas.

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: 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 larger than 1, and an element concentration ratio (at. % ratio) of Gd to Fe or Fe—Co is set in a range of 28.0 ≦Gd≦29.0. 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 23.5≦Tb≦25.5 or 25.5≦Dy≦28.5.

Abstract: The present invention provides a method of recording information on a magneto-optical recording medium of domain wall displacement type having a preformat area and a data area succeeding thereto, comprising the steps of generating a reproduction signal from said medium by utilizing a light beam, detecting a reference position based on said reproduction signal, determining, based on a result of the detection, a recording start timing at which a formation of a recording magnetic domain is started at a distance at least not shorter than a displacement amount of a domain wall away from a start position of said data area; and starting a recording with said determined recording start timing.

Abstract: According to the present invention, a light beam is radiated to an area between recording tracks while the intensity of a magnetic field from the outside to a magneto-optical recording medium is suppressed to 50 Oe or less, whereby magnetic anisotropy formed between the recording tracks is set to be lower than that of the magnetic layer on the recording tracks, and micro-domains, for example, having a diameter smaller than a half-width of a light beam for reproduction in a film surface direction are formed on recording tracks. Because of this method, the influence of a leakage magnetic field in the magneto-optical recording medium adopting a DWDD reproducing system is alleviated.

Abstract: By irradiating a light beam between recording tracks of the magneto-optical recording medium, the magnetic anisotropy of at least one layer selected from the group consisting of the domain wall displacement layer and the recording layer formed between the recording tracks can be made lower than that of said layers on the recording tracks, and a bias magnetic field is applied at least between recording tracks while a light beam is radiated. Because of this, initialization of a medium may be conducted simultaneously.

Abstract: On a disk-shaped substrate with pits and grooves, a first dielectric layer, a magnetic layer, and a second dielectric layer are formed. A data region used for recording/reproduction includes a plurality of tracks, and is divided into a plurality of segments. Each segment includes a pit region and a groove region. Recording/reproducing tracks are composed of the grooves. Magnetic anisotropy of a magnetic layer positioned on each of lands between the respective recording/reproducing tracks is reduced to a level lower than that of magnetic anisotropy of the magnetic layers positioned on the grooves, so that the recording/reproducing tracks are magnetically separated. On an inner side of an innermost recording/reproducing track and on an outer side of an outermost recording/reproducing track, at least one dummy track is provided, respectively.

Abstract: A magneto-optic recording medium in which information is reproduced while a recording magnetic domain is enlarged by displacing a domain wall based on a temperature distribution formed by a beam of light and having a maximum temperature Tr. The recording medium comprises a reproducing layer in which a domain wall is displaced, a recording layer for holding a recording magnetic domain corresponding to information, and a cutoff layer disposed between the reproducing layer and the recording layer and having a Curie temperature lower than those of the reproducing layer and recording layer.

Abstract: A magnetooptical recording medium includes a first magnetic layer, a second magnetic layer whose Curie temperature is lower than that of the first magnetic layer, and a third magnetic layer, comprising a vertically-magnetizing film, whose Curie temperature is higher than that of the second magnetic layer. The first magnetic layer, the second magnetic layer and the third magnetic layer are in a state of exchange coupling with each other at a portion of a vertically-magnetizing film. A domain walls formed in the first magnetic layer moves when the temperature of the medium has been raised to at least the Curie temperature of the second magnetic layer.

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: 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.