Abstract: A three-dimensional printing system includes a resin vessel containing resin, an imaging bar, a movement mechanism coupled to the imaging bar, and a controller. The imaging bar includes an arrangement of light emitting devices that selectively emit radiation from an exit surface of the imaging bar to define a build plane in the resin. The exit surface of the imaging bar is preferably less than 10 millimeters from the build plane. The controller is configured to scan the imaging bar along a scan axis and, concurrent with scanning, operate the imaging bar to selectively image a layer of resin at the build plane.

Abstract: A preparation method using micro-nano bubbles as crystal seeds to induce spherical or spherical-type silver power production, said method specifically comprising the steps of: pre-adding a prepared dispersing agent solution to a reaction vessel, within the reaction vessel, simultaneously adding a prepared oxidizing solution (an aqueous solution containing silver ions or a silver ammonia solution) and a reducing solution (an aqueous solution containing one or a plurality of hydroxylamine compounds, vitamin C, formaldehyde or hydrazine hydrate), performing a reduction reaction under vigorous stirring, and using the pre-generated micro-nano bubbles within the dispersing agent solution as crystal seeds, the micro-nano bubbles crystal seeds effectively controlling the particle size of reduced silver particles throughout the reduction reaction. The method effectively controls the particle size of the silver powder during production, and also controls the crystal nucleus growth rate and dispersibility.

Abstract: The problem of the invention is to provide a process for producing a magnetic recording medium which exhibits both of excellent thermal stability and favorable writing capability. The process for producing the magnetic recording medium of the invention includes the steps of: (A) forming the first magnetic recording layer while monotonously changing a substrate temperature; and (B) forming the second magnetic recording layer while monotonously changing the substrate temperature wherein the material of the second magnetic recording layer is different from the material of the first recording layer, wherein the substrate temperature at the beginning of the step (B) is set such that the magnetic anisotropy constant of the first magnetic recording layer and the magnetic anisotropy constant of the second magnetic recording layer is changed monotonously at the interface between the first and second magnetic recording layers.

Abstract: Sub-50-nm structures are formed using sequential top-down and bottom up lithographies in conjunction with selective etching. The preferred rendition of the method involves: (a) rough lithographic patterning, (b) size/shape selected nanostructure deposition, (c) resist reflow around the nanostructures, and (d) selective removal/etching of the nanostructure.

Abstract: According to one embodiment, a magnetic recording medium including a substrate and a magnetic recording layer formed on the substrate and including a plurality of projections is obtained. The array of the plurality of projections includes a plurality of domains in which the projections are regularly arranged, and a boundary region between the domains, in which the projections are irregularly arranged. The boundary region is formed along a perpendicular bisector of a line connecting the barycenters of adjacent projections.

Abstract: A thermally assisted magnetic recording medium (1) includes a substrate (101), an underlayer (3) that is formed above the substrate (101), and a magnetic layer (107) that is formed on the underlayer (3) and contains an alloy having an L10 structure as a main component. The underlayer (3) is formed by continuously laminating a first underlayer (104) having a BCC structure with a lattice constant that is 0.302 to 0.332 nm, a second underlayer (105) that has a NaCl structure including C, and a third underlayer (106) that is composed of MgO.

Abstract: A substrate for a magnetic recording medium having a disc shape with a central hole is provided in which the surface roughness of the principal surface of the substrate is 1 angstrom or less in terms of root mean square roughness (Rq) when a space period (L) of an undulation in the circumferential direction is in the range 10 to 1,000 ?m, and in which when a component in the vertical axis direction of a line segment Z connecting a point A with the space period (L) of 10 ?m and a point B with the space period (L) of 1,000 ?m in a curve S marked on a double logarithmic graph which is obtained by analyzing the surface roughness using a spectrum and in which the horizontal axis is set to the space period (L) (?m) and the vertical axis is set to the power spectrum density (PSD) (k·angstrom2·?m) (where k is a constant) is defined as H and a displacement at which the component in the vertical axis direction of the curve S is the maximum with respect to the line segment Z is defined as ?H, a value (P) expressed by (?

Abstract: The embodiments disclose a data storage device including a thickness gradient heat sink layer deposited over a heat sink layer deposited over a substrate, a thickness gradient non-magnetic thermal resist layer deposited over the thickness gradient heat sink layer, and a magnetic layer deposited over the thickness gradient non-magnetic thermal resist layer.

Abstract: A glass substrate for a magnetic disk of the invention is a disk-shaped glass substrate for a magnetic disk where the substrate has a main surface and end face and is subjected to chemical reinforcement treatment, and is characterized in that the penetration length in the uppermost-portion stress layer on the main surface is 49.1 ?m or less, and that assuming that an angle between the main surface and compressive stress in the stress profile by a Babinet compensator method is ?, a value y of {12·t·ln(tan ?)+(49.1/t)} is the penetration length in the uppermost-portion stress layer or less.

Abstract: A sheet includes a pulp fiber and a linear magnetic material. The linear magnetic material has a substantially large Barkhausen effect. The linear magnetic material also has irregularities at an outer periphery of the linear magnetic material. The sheet in which the magnetic material is inhibited from being exposed at both surfaces of the sheet can be provided.

Abstract: A method and apparatus for planarizing magnetically susceptible layers of substrates is provided. A patterned resist is formed on the magnetically susceptible layer, and the substrate is subjected to a plasma immersion ion implantation process to change a magnetic property of the magnetically susceptible layer according to the pattern of the resist material. The substrate is subjected to a plasma material removal process either before or after the implantation process to planarize the surface of the magnetically susceptible layer resulting from the implantation process. The plasma material removal process may be directional or non-directional.

Abstract: The present disclosure relates to a protective layer composition that includes TixSiyA, where A is Cm, CmNl, OnCm, or OnCmNl and x, y, l, m, and n are positive integers. In one implementation, the protective layer composition has a ratio of x over (x+y) in the range of between about 0.1 and about 1.0. In another implementation, the protective layer composition has a ratio of x over (x+y) in the range of between about 0.3 and about 0.9. In yet another implementation, the protective layer composition has a ratio of x over (x+y) that is about 0.6. The protective layer composition may be amorphous. Also, the protective layer composition may include an atomic percentage of Ti that is less than about 20%. In one implementation of the protective layer composition, x is 2, y is 1, and A is C3.

Abstract: A data device may have at least a magnetic lamination with a thermal retention structure deposited on a substrate and configured to maintain a predetermined temperature for a predetermined amount of time. Such predetermined temperature and amount of time may allow for the growth of a magnetic layer with a predetermined magnetic anisotropy.

Abstract: A magnetic recording medium is disclosed which has excellent corrosion resistance, even with a protective layer of thickness 2 nm or less. The magnetic recording medium includes, on a substrate, a magnetic layer and a carbon-based protective layer. The thickness of the carbon-based protective layer is 2 nm or less, and the contact angle of water on a surface of the carbon-based protective layer is 25° or greater and less than 60°.

Abstract: A magnetic recording medium permits high recording densities while simultaneously satisfying requirements for the high-frequency SNR characteristic and the Squash characteristic. The magnetic recording medium includes at least a soft magnetic underlayer and a magnetic recording layer on a nonmagnetic substrate. The soft magnetic underlayer has a stacked structure that includes a soft magnetic layer on the nonmagnetic substrate side, an exchange coupling control layer, and a soft magnetic layer on the magnetic recording layer side. The soft magnetic layer on the magnetic recording layer side has a higher relative permeability characteristic frequency (the frequency at which the relative permeability is reduced by 50% compared with the relative permeability at 10 MHz) than the soft magnetic layer on the nonmagnetic substrate side, and the soft magnetic layer on the nonmagnetic substrate side has a higher relative permeability than the soft magnetic layer on the magnetic recording layer side.

Abstract: The embodiments disclose a method for fabricating high contrast stacks, including depositing materials on a substrate to form an antiferromagnetic coupling thin film layer on top of a first half of the magnetic layer of a stack, depositing a portion of a second half of the magnetic layer on top of the antiferromagnetic coupling thin film layer to couple the first and second half of the magnetic layers to the antiferromagnetic coupling thin film layer and bit-patterning a portion of the second half of the magnetic layer and the antiferromagnetic coupling thin film layer.

Abstract: Disclosed is a thermally assisted magnetic recording medium comprising a substrate, a plurality of underlayers formed on the substrate, and a magnetic layer which is formed on the underlayers and predominantly comprised of an alloy having a L10 structure, characterized in that at least one of the underlayers is predominantly comprised of MgO and comprises at least one oxide selected from SiO2, TiO2, Cr2O3, Al2O3, Ta2O5, ZrO2, Y2O3, CeO2, MnO, TiO and ZnO. The thermally assisted magnetic recording medium has a magnetic layer comprised of fine magnetic crystal grains, exhibiting a sufficiently weak exchange coupling between magnetic grains, and having a minimized coercive force dispersion.

Abstract: According to one embodiment, a perpendicular magnetic recording medium includes a substrate, and a multilayered magnetic recording layer formed on the substrate by alternately stacking two or more magnetic layers and two or more nonmagnetic layers. The magnetic layers and nonmagnetic layers of the multilayered magnetic recording layer are continuous layers. The magnetic layer includes a magnetic material portion, and a plurality of pinning sites dispersed in the magnetic material portion and made of a nonmagnetic metal different from a nonmagnetic material as a main component of the nonmagnetic layer. This perpendicular magnetic recording medium has magnetic characteristics by which a gradient a of a magnetization curve near the coercive force is 5 or more.

Abstract: A high-resolution magnetic encoder system includes a magnetic resistive sensor, a fixed suspension, and a mechanism. The magnetic resistive sensor is mounted to the fixed suspension above a magnetic medium having at least one magnetic track. The fixed suspension is attached to the mechanism, such as a housing, a substrate, and/or an electronic board. The sensor is adapted to perform a relative movement with respect to and in close contact to the surface of the magnetic medium. The magnetic medium may be protected by an overcoat layer. The magnetic resistive sensor may be Giant Magnetic-Resistive (GMR) sensor and/or a Tunneling Magnetic-Resistive Sensor (TMR).

Abstract: A recording layer is formed on a substrate, and a high thermal conductor having a thermal conductivity higher than that of the recording layer is disposed inside a plurality of recording bit regions constituting the recording layer, respectively. Furthermore, the recording layer is formed with a separating portion which divides the recording layer into the plurality of recording bit regions. The separating layer is filled with a low thermal conductor having a thermal conductivity lower than that of the recording layer.

Abstract: A patterned perpendicular magnetic recording disk with discrete data islands of recording layer (RL) material includes a substrate, a patterned exchange bridge layer of magnetic material between the substrate and the islands, and an optional exchange-coupling control layer (CCL) between the exchange bridge layer and the islands. The exchange bridge layer has patterned pedestals below the islands. The exchange bridge layer controls exchange interactions between the RLs in adjacent islands to compensate the dipolar fields between islands, and the pedestals concentrate the flux from the write head. The disk may include a soft underlayer (SUL) of soft magnetically permeable material on the substrate and a nonmagnetic exchange break layer (EBL) on the SUL between the SUL and the exchange bridge layer. In a thermally-assisted recording (TAR) disk a heat sink layer may be located below the exchange bridge layer and the SUL may be optional.

Abstract: The present invention provides a magnetic latent image holding body in which the surface thereof has water repellency and a magnetic latent image is visualized by a liquid developer that contains a magnetic toner and an aqueous medium.

Abstract: According to one embodiment, there is provided a magnetic recording medium which includes a plurality of magnetic dot rows in which there is a phase shift between adjacent dot rows, and dots are arranged in a zigzag manner in a predetermined number of dot rows which are simultaneously read.

Abstract: A thin biaxially oriented film excellent in dimensional stability against humidity change, as well as a magnetic recording medium and a film capacitor using the same. The present invention provides a laminated biaxially oriented film comprising: at least one layer comprising an aromatic polyester (a); and at least one layer of a polyolefin (b) having a melting point of from 230 to 280° C.; wherein the ratio of the polyolefin (b) is from 2 to 60% based on the entire weight of the film, and the film thickness is from 1 to 10 ?m.

Abstract: A perpendicular magnetic recording medium is disclosed. The perpendicular magnetic recording medium includes a substrate; an intermediate layer disposed on the substrate; at least one soft underlayer (SUL) disposed between the substrate and the intermediate layer, wherein the soft underlayer contacts the intermediate layer and the substrate; and a magnetic recording layer disposed on the intermediate layer.

Abstract: A magnetic recording disk with pre-patterned surface features of elevated lands and recessed grooves or trenches, like a discrete-track media (DTM) or bit-patterned media (BPM) disk, has a planarized surface. A multilayered disk overcoat is used to protect the recording layer, and at least one of the overcoat layers functions as a stop layer for terminating a chemical-mechanical polishing (CMP) process that substantially planarizes the disk. All of the layers of the multilayered overcoat are located above the lands, but none of the overcoat layers, or a number of layers less than the number of layers over the lands, is located above the recesses.

Abstract: Composite magnetic recording media are described. A composite structure is a structure that is formed of multiple components. For example, a composite magnetic recording medium may include a substrate, an underlayer formed over the substrate, the underlayer defining a coating surface, and a magnetic layer formed over the coating surface of the underlayer. Composite magnetic recording media constructed according to the materials and techniques disclosed may provide dimensional flexibility while exhibiting improved physical or electromagnetic characteristics. In some examples, dimensional flexibility may be achieved by pairing a substrate greater than or equal to approximately 4000 nanometers thick with an underlayer less than or equal to approximately 890 nanometers thick.

Abstract: A high density magnetic recording medium including aggregates of magnetic nanoparticles arranged stably and efficiently in demarcated sections in the surface of a substrate is manufactured by the steps of forming a plurality of parallel tracks in the surface of the substrate, forming a plurality of minute recesses serially at approximately equal intervals in each of the tracks, casting a liquid dispersion of magnetic nanoparticles into the minute recesses, and evaporating dispersing medium from the liquid dispersion, thereby forming an aggregate of magnetic nanoparticles in each of the minute recesses.

Abstract: Disclosed is a method for manufacturing a substrate provided with a surface portion having a plurality of concave and convex configurations. The method includes a step of applying a solution between a mold having a configuration corresponding to the concave and convex configurations, and a substrate base member, the solution obtained by dissolving a constructional material for composing the surface portion in a solvent; a step of forming the surface portion by drying the solvent in a state that the solution is applied between the mold and the substrate base member; and a step of releasing the mold from the surface portion. The mold satisfies requirements that a contact angle of a contact portion of the mold to be contacted with the solution is smaller than 90° with respect to the solvent, and that a work of adhesion between the contact portion and the constructional material is smaller than a work of adhesion between the contact portion and the solvent.

Abstract: A magnetic recording medium which has a non-magnetic substrate and a magnetic layer formed on the non-magnetic substrate, in which the magnetic layer contains magnetic powder with a particle size of 40 nm or less and a binder, an autocovariance length Ma of the magnetic layer in its lengthwise direction is 70 nm or less, an autocovariance length Mb of the magnetic layer in its widthwise direction is 80 nm or less, and a ratio Ma/Mb is from 0.80 to 1.20.

Abstract: A method and apparatus for planarizing magnetically susceptible layers of substrates is provided. A patterned resist is formed on the magnetically susceptible layer, and the substrate is subjected to a plasma immersion ion implantation process to change a magnetic property of the magnetically susceptible layer according to the pattern of the resist material. The substrate is subjected to a plasma material removal process either before or after the implantation process to planarize the surface of the magnetically susceptible layer resulting from the implantation process. The plasma material removal process may be directional or non-directional.

Abstract: A continuous-media perpendicular magnetic recording disk with an oxide-containing granular Co alloy recording layer (RL) having minimal grain size dispersion has an ordered nucleation layer (ONL) formed below RL. The ONL has ordered nucleation sites arranged in a generally repetitive pattern. The nucleation sites are generally surrounded by non-nucleation regions of a different material than the nucleation sites. The Co-alloy grains of the subsequently deposited RL grow on the nucleation sites and the oxide of the RL become generally segregated on the non-nucleation regions. The ordered nucleation sites may be formed of a Ru-containing material and the non-nucleation regions may be formed of an oxide. The ONL is formed by nanoimprint lithography, preferably by a master mold fabricated with a method using self-assembling block copolymers for creating periodic nanometer scale features.

Abstract: A recording medium includes a magnetic material and a pulp-fiber, a minimum value of shortest distances between the magnetic material and an edge of the recording medium substantially parallel to the pulp-fiber orientation direction being about 1 mm or more.

Abstract: A perpendicular recording magnetic media with a partially-oxidized cap layer combines a second oxide layer with a first cap layer to form the singular, partially-oxidized cap. The oxidized portion and the non-oxidized portion of the partially-oxidized layer are sputtered from a same target and have a same composition of metallic elements. The Ms of the oxidized portion is about twice as high as the non-oxidized portion. The oxidized portion has a thickness in the range of about 5 to 25 angstroms. The layer composition may comprise CoPtCrBTa, with a Cr at % of about 18-24%, Pt at about 13-20%, B at about 4-10%, and Ta at about 0-2%.

Abstract: An aspect of the present invention relates to a radiation-curable polyurethane resin composition comprising a polyurethane resin containing a radiation-curable functional group and/or starting material compounds thereof, as well as component C in the form of a phenol compound, and component D in the form of at least one compound selected from the group consisting of a piperidine-1-oxyl compound, a nitro compound, a benzoquinone compound and a phenothiazine compound.

Abstract: In a recording medium, a CrN film layer comprising a B1 phase crystal structure.

Abstract: A UV nanoimprint method comprising performing compression molding by pressing a mold having a pattern formed on the surface thereof against a work prepared by forming a thin film composed of an ultraviolet-curable resin on a substrate, and irradiating with ultraviolet light, either concurrently with the compression molding or after the compression molding, thereby transferring the pattern to the thin film, wherein the ultraviolet light is irradiated using an ultraviolet light irradiation apparatus equipped with temperature rise suppression means, and a light source that does not continuously emit heat rays together with ultraviolet light is used as a light source of the ultraviolet light irradiation apparatus.

Abstract: A magnetic storage medium is formed of magnetic nanoparticles that are encapsulated within carbon nanotubes, which are arranged in a substrate to facilitate the reading and writing of information by a read/write head. The substrate may be flexible or rigid. Information is stored on the magnetic nanoparticles via the read/write head of a storage device. These magnetic nanoparticles are arranged into data tracks to store information through encapsulation within the carbon nanotubes. As carbon nanotubes are bendable, the carbon nanotubes may be arranged on flexible or rigid substrates, such as a polymer tape or disk for flexible media, or a glass substrate for rigid disk. A polymer may assist holding the nano-particle filled carbon-tubes to the substrate.

Abstract: It is possible to improve the recording and reproducing S/N ratio, the reproduction signal intensity, and the degree of high density recording. There are provided a plurality of recording tracks formed on a substrate, each recording track being formed of a magnetic material, and non-recording sections formed on the substrate, each non-recording section separating adjacent recording tracks, each recording track including a plurality of recording sections and connecting sections for connecting the recording sections adjacent thereto in a track longitudinal direction, and each connecting section having a cross-sectional area in a track width direction that is smaller than a cross-sectional area in a track width direction of adjacent recording sections.

Abstract: A magnetic recording medium is provided in which recording elements and concave portions have a clear difference in terms of magnetism at the boundaries therebetween, and which has favorable production efficiency. The magnetic recording medium includes a substrate; a recording layer formed in a predetermined concavo-convex pattern over the substrate, convex portions of the concavo-convex pattern serving as recording elements; and a filler portion filling a concave portion between the recording elements. A center part of a bottom surface of the concave portion protrudes from edge parts of the bottom surface of the concave portion in a direction away from the substrate.

Abstract: A perpendicular type of magnetic recording medium includes a substrate, a soft magnetic underlying section including a plurality of distinct layers soft magnetic material, a recording section, and an intermediate section upon which the recording section is formed. The intermediate section is provided to improve the crystal orientation and impart a desired magnetic characteristic to the recording section. An uppermost one of the layers of soft magnetic material which, of all of the layers of soft magnetic material, is disposed closest to the intermediate section is predisposed to induce the intermediate section to crystallize in a desired way as it is formed. Therefore, the intermediate section may have a minimal thickness and yet achieve a crystallization that is sufficient to control the forming of the recording section.

Abstract: A perpendicular type of magnetic recording medium has a multi-layered recording structure made up of a plurality of ferro-magnetic layers and a non-magnetic layer interposed between the plurality of ferro-magnetic layers, and the perpendicular magnetic anisotropy energy of the lower ferro-magnetic layer is greater than the perpendicular magnetic anisotropy energy of the upper ferro-magnetic layer. Accordingly, the lower ferro-magnetic layer may be easily magnetically reversed by a magnetic field applied during a write operation. Thus, the perpendicular type of magnetic recording medium exhibits an enhanced thermal stability and write-ability.

Abstract: A method of providing particles configured for use in magnetic recording media includes providing a set of particles having a size distribution, and removing a fraction of the set of particles from the size distribution. The fraction is less than approximately 50% by volume and includes the most massive particles in the size distribution.

Abstract: Provided is a magnetic recording medium substrate appropriate for a discrete medium and capable of fabricating a magnetic recording medium to/from which data can be written or read stably. Coaxial grooves (2) are formed on the surface of a resin substrate (1). The groove (2) has a width (T2) greater than a width (T1) of a track (3). Accordingly, when a magnetic layer is layered on the resin substrate (1), magnetic layers formed on the adjacent tracks (3) are not brought into contact and it is possible to prevent the problem that the magnetic layer is embedded in the groove (2). Thus, it is possible to physically separate the track (3) by the groove (2) and fabricate a magnetic recording medium to/from which data can written and read stably.

Abstract: Methods and apparatus for forming substrates having magnetically patterned surfaces is provided. A magnetic layer comprising one or more materials having magnetic properties is formed on a substrate. The magnetic layer is subjected to a patterning process in which selected portions of the surface of the magnetic layer are altered such that the altered portions have different magnetic properties from the non-altered portions without changing the topography of the substrate. A protective layer and a lubricant layer are deposited over the patterned magnetic layer. The patterning is accomplished through a number of processes that expose substrates to energy of varying forms. Apparatus and methods disclosed herein enable processing of two major surfaces of a substrate simultaneously, or sequentially by flipping. In some embodiments, magnetic properties of the substrate surface may be uniformly altered by plasma exposure and then selectively restored by exposure to patterned energy.

Abstract: A magnetic recording medium used for perpendicular magnetic recording, the magnetic recording medium comprising: a substrate having a first surface and a second surface opposite to the first surface; a magnetic recording medium constituent layer formed on the first surface of the substrate, the magnetic recording medium constituent layer including at least a magnetic recording layer; a non-magnetic metal film formed on the second surface of the substrate; and a carbon-based protective film formed on the non-magnetic metal film.

Abstract: According to one embodiment, a method of manufacturing a patterned medium includes depositing a magnetic recording layer and applying an ultraviolet curable resin on both surfaces of a medium substrate, pressing a first resin stamper and a second resin stamper each including patterns of recesses and protrusions, corresponding to a patterned medium, against both surfaces of the medium substrate in such a manner that a direction from a center of the medium substrate toward a center of the first resin stamper is off-oriented from a direction from the center of the medium substrate toward a center of the second resin stamper to imprint the patterns of recesses and protrusions on the ultraviolet curable resin, and irradiating the ultraviolet curable resin with an ultraviolet ray through each of the first and second resin stampers to cure the ultraviolet curable resin.

Abstract: A perpendicular magnetic recording medium is provided, which has a soft magnetic layer, a seed layer, a first intermediate layer, a second intermediate layer and a perpendicular magnetic recording layer, formed in this order on a non-magnetic substrate, and is characterized in that the seed layer is comprised of a (002) crystal plane-orientated hcp structure, the first intermediate layer is comprised of a (110) crystal plane-orientated bcc structure and the second intermediate layer is comprised of a (002) crystal plane-orientated hcp structure. The (110) crystal plane-orientated bcc structure comprises at least 60 atomic % of Cr. The magnetic recording medium has fine and well discrete magnetic crystal grains with extremely small size and exhibits good perpendicular orientation in the perpendicular magnetic recording layer, and thus, the medium is capable of recording and reproducing information with high density.

Abstract: A perpendicular magnetic recording medium comprising a pair of soft magnetic layers that are laminated via a non-magnetic layer and antiparallel-coupled to each other and that are provided between a non-magnetic substrate and a magnetic recording layer, wherein spike noise and medium noise can be positively suppressed when information recording and reproduction are carried out at high recording surface density. At least one pair of soft magnetic layers are laid and formed via a non-magnetic layer on a substrate of a non-magnetic material so that magnetic characteristics obtained by integrating the pair of soft magnetic layers have a magnetic hysteresis to thereby prevent the formation of a magnetic domain wall.

Abstract: A perpendicular magnetic recording medium, which includes a first magnetic recording layer, a second magnetic recording layer, and a third magnetic recording layer disposed sequentially on a nonmagnetic substrate, and a coupling layer formed between the first and second magnetic recording layers. The first, second and third magnetic recording layers have an easy axis of magnetization in a direction perpendicular to a film plane of the nonmagnetic substrate. The first and second magnetic recording layers are ferromagnetically coupled via the coupling layer.