Abstract: The invention provides a magnetic recording medium, and a magnetic recording and reproducing apparatus. The magnetic recording medium includes a substrate 11, an under layer 12 formed on the substrate 11, a magnetic recording layer 13 formed on the under layer 12, and a protective layer 14 formed on the magnetic recording layer 13. The magnetic recording layer 13 is composed of a primary recording layer 14 and a secondary recording layer 15 which are mutually exchange-coupled. The primary recording layer 14 has magnetic grains and a nonmagnetic material that surrounds the magnetic grains, and has a perpendicular magnetic anisotropy. The secondary recording layer 15 is made of a material having a negative crystal magnetic anisotropy and its easy plane of the magnetization is a plane of the medium.

Abstract: A master is provided for use in a magnetic printing process. Illustratively, the master is used for printing servo patterns on a magnetic recording medium. The master includes a substrate on which a magnetic underlayer material is disposed. A second magnetic material is disposed over the magnetic underlayer material so as to form a plurality of teeth adapted for use in the magnetic printing process. The teeth may be formed in the second material by an additive or subtractive process. Further, the dimensions of the teeth may be selected to optimize use of the master in a magnetic printing process on perpendicular media.

Abstract: A magnetic recording medium includes a non-magnetic granular layer, and a recording layer provided on the non-magnetic granular layer, wherein the recording layer includes a first granular magnetic layer provided on the non-magnetic granular layer, and a second granular magnetic layer provided on the first granular magnetic layer, and a non-magnetic material magnetically separating metal grains of the non-magnetic granular layer is different from a non-magnetic material magnetically separating magnetic grains of the first granular magnetic layer.

Abstract: A magnetic recording medium having a Au, Ag-containing magnetic layer having Co, Cr, Ag and Au; the magnetic recording layer having Co-containing magnetic grains surrounded by substantially nonmagnetic Cr-containing grain boundaries; wherein said Ag and said Au are substantially immiscible in the Co-containing magnetic grains is disclosed.

Abstract: Embodiments of the invention provide a thermally assisted magnetic recording medium, which can overcome resistance against thermal fluctuation at RT and write capability, obtain a drastic temperature variation in coercive force at right below the recording temperature, and be formed at low temperature. In one embodiment, the medium has a layered structure formed of a lower high-KF ferromagnetic (F) layer formed on a substrate, satisfying TW<TC, an intermediate low-KAF antiferromagnetic (AF) layer satisfying TB<TW, and an upper ferromagnetic (F) layer for recording and reproducing, satisfying TW<TC, where TW is a recording temperature, TC is a Curie point, TN is a Neel point, TB is a blocking temperature, KF is a ferromagnetic magnetocrystalline anisotropy constant, and KAF is an antiferromagnetic magnetocrystalline anisotropy constant.

Abstract: A magnetic recording medium (10) has a substrate (12) and a perpendicular magnetic recording layer (30) formed over the substrate (12). The perpendicular magnetic recording layer (30) has a granular layer (20) in which a magnetic signal is recorded and a continuous film layer (24) magnetically coupled to the granular layer (20). The continuous film layer (24) has hard magnetic portions (204) formed in positions corresponding to the recording regions where magnetic signals are recorded in the granular layer (20) and magnetic shield portions (202) formed between the hard magnetic portions (204), each having a magnetization curve whose slope is larger than those of the hard magnetic portions in the region where the applied magnetic filed is zero when the magnetization curve is measured, and each having a residual magnetic polarization smaller than those in the hard magnetic portions.

Abstract: A perpendicular magnetic recording media is disclosed which employs inexpensive materials in the intermediate layer of the high-recording density media while exhibiting magnetic characteristics comparable or superior to those of media using Ru or Re. A perpendicular magnetic recording apparatus employing this perpendicular magnetic recording media also is disclosed. The perpendicular magnetic recording media has a nonmagnetic substrate, a soft magnetic backing layer formed on the nonmagnetic substrate, a seed layer formed on the soft magnetic backing layer, an intermediate layer formed on the seed layer, a magnetic layer formed on the intermediate layer, and a protective layer formed on the magnetic layer. The intermediate layer comprises an alloy with the hcp structure containing 55 at % or more Zn, the magnetic layer comprises an alloy with the hcp structure containing Co, and the ??50 value of the orientation plane (0002) of the magnetic layer is between 1.5° and 4°.

Abstract: The present invention provides a perpendicular magnetic recording medium that can reduce noise by further size reduction and isolation of magnetic grains in a magnetic recording layer and can increase the recording density by improvement of the SNR. A typical configuration of a perpendicular magnetic recording medium according to the present invention is a perpendicular magnetic recording medium having a magnetic recording layer with a granular structure in which non-magnetic grain boundary portions are formed between magnetic grains that have grown continuously in a columnar shape, wherein the grain boundary portions contain a plurality of kinds of oxides.

Abstract: A silicon/gold (Si/Au) bilayer seed structure is located in a film stack between an amorphous or crystalline lower layer and an upper layer with a well-defined crystalline structure. The seed structure includes a Si layer on the generally flat surface of the lower layer and a Au layer on the Si layer. The Si/Au interface initiates the growth of the Au layer with a face-centered-cubic (fcc) crystalline structure with the (111) plane oriented in-plane. The upper layer grown on the Au layer has a fcc or hexagonal-close-packed (hcp) crystalline structure. If the upper layer is a fcc material its [111] direction is oriented substantially perpendicular to the (111) plane of the Au layer and if the upper layer is a hcp material, its c-axis is oriented substantially perpendicular to the (111) plane of the Au layer.

Abstract: A perpendicular magnetic recording medium adapted for high recording density and high data recording rate comprises a non-magnetic substrate having at least one surface with a layer stack formed thereon, the layer stack including a perpendicular recording layer containing a plurality of columnar-shaped magnetic grains extending perpendicularly to the substrate surface for a length, with a first end distal the surface and a second end proximal the surface, wherein each of the magnetic grains has: (1) a gradient of perpendicular magnetic anisotropy field Hk extending along its length between the first end and second ends; and (2) predetermined local exchange coupling strengths along the length.

Abstract: A perpendicular magnetic recording medium is disclosed in which a soft magnetic layer used as a low Ku layer can be stably produced with high performance. Thermal stabilization of magnetization, ease of writing by a magnetic head, and SNR also are improved. A method of manufacturing the medium is disclosed. The perpendicular magnetic recording medium includes at least a nonmagnetic underlayer, a magnetic recording layer, and a protective layer formed in this order on a nonmagnetic substrate. The magnetic recording layer includes a low Ku layer having a relatively small perpendicular magnetic anisotropy constant (Ku value), and a high Ku layer in which the Ku value is relatively large, and the low Ku layer includes a soft magnetic thin film including an iron group element-based microcrystal structure, in which a nitrogen element is added to a ferromagnetic material mainly containing one of metals of Co, Ni and Fe or an alloy of the metal.

Abstract: A patterned perpendicular magnetic recording medium has discrete magnetic islands, each of which has a recording layer (RL) structure that comprises two exchange-coupled ferromagnetic layers. The RL structure may be an “exchange-spring” RL structure with an upper ferromagnetic layer (MAG2), sometimes called the exchange-spring layer (ESL), ferromagnetically coupled to a lower ferromagnetic layer (MAG1), sometimes called the media layer (ML). The RL structure may also include a coupling layer (CL) between MAG1 and MAG2 that permits ferromagnetic coupling. The interlayer exchange coupling between MAG1 and MAG2 may be optimized, in part, by adjusting the materials and thickness of the CL. The RL structure may also include a ferromagnetic lateral coupling layer (LCL) that is in contact with at least one of MAG1 and MAG2 for mediating intergranular exchange coupling in the ferromagnetic layer or layers with which it is in contact (MAG2 or MAG1).

Abstract: A perpendicular magnetic recording medium including: a substrate; a perpendicular magnetic recording layer disposed over the substrate; a soft magnetic underlayer disposed between the substrate and the perpendicular magnetic recording layer; a shunting layer disposed under the soft magnetic underlayer; and an isolation layer disposed between the soft magnetic underlayer and the shunting layer and providing magnetic isolation between the shunting layer and the other layers disposed over the shunting layer are provided. The shunting layer is magnetically separated from the other magnetic layers disposed over the shunting layer, and shunts a magnetic field generated by the magnetic domain walls of the soft magnetic underlayer such that the magnetic field cannot reach a magnetic head, thereby increasing a signal-to-noise ratio (SNR).

Abstract: It is an object to provide a simple method capable of producing a magnetic storage medium, a magnetic storage medium and an information storage device which may be produced by a simple production method with a high recording density, and a magnetic disk is produced by a production method having: a film-forming process of forming, on a substrate 61, a magnetic film made of a Co—Cr—Pt alloy and having a thickness of less than 10 nm; and an ion injection process of forming, by reducing saturation magnetization by locally injecting ions into a point other than plural points that become magnetic dots on each of which information is magnetically recorded, a between-dot separator having saturation magnetization smaller than saturation magnetization of the magnetic dots, between the magnetic dots.

Abstract: In a perpendicular magnetic recording medium which includes a substrate (1) of a nonmagnetic material, first and second nonmagnetic underlayers (4 and 5) formed on the substrate, and a perpendicular magnetic recording layer (6) formed on the first and the second nonmagnetic underlayers, the first nonmagnetic underlayer is made of an amorphous nonmagnetic metal material containing a metal element which forms a face-centered cubic (fcc) crystal structure by a simple substance. The second nonmagnetic underlayer is formed on the first nonmagnetic underlayer in contact with the first nonmagnetic underlayer and made of a nonmagnetic material containing a hexagonal close packed structure. The perpendicular magnetic recording layer is formed on the second nonmagnetic underlayer in contact with the second nonmagnetic layer.

Abstract: A recording medium providing improved writeability in perpendicular recording applications includes a magnetic recording layer having an axis of magnetic anisotropy substantially perpendicular to the surface thereof, an exchange-spring layer ferromagnetically exchange coupled to the magnetic recording layer and having a coercivity less than the magnetic recording layer coercivity, and a coupling layer between the magnetic recording layer and the exchange-spring layer. The coupling layer regulates the ferromagnetic exchange coupling between the magnetic recording layer and the exchange-spring layer.

Abstract: According to one embodiment, a magnetic recording medium includes a substrate, a first underlayer formed on the substrate and including an amorphous alloy containing Ni, a crystalline second underlayer formed on the first underlayer and including simple Cr or an alloy containing Cr, and a magnetic recording layer formed on the second underlayer and including at least one element of Fe and Co and at least one element of Pt and Pd, and containing magnetic crystal grains having an L10 structure. An oxygen amount remaining on the upper surface of the second underlayer is larger than an oxygen amount remaining on the lower surface of the second underlayer, and a normal line to a (001) plane of the magnetic crystal grains in the magnetic recording layer is oriented with a tilt angle in a range of 3 to 25° to a normal line to a medium plane.

Abstract: A method of producing a perpendicular magnetic recording medium with a magnetic recording layer formed from ferromagnetic crystal grains and oxide-including non-magnetic crystal grain boundaries and provided on a non-magnetic substrate. The method is initiated by forming the magnetic recording layer by a reactive sputtering method using rare gas containing 2% by volume to 10% by volume (both inclusively) of oxygen gas at an initial stage of film formation. The method continues by successively forming the magnetic recording layer by reactive sputtering while reducing the concentration of the oxygen gas. The method may further include forming an undercoat layer of Ru or a Ru-alloy under the magnetic recording layer. In this manner, a granular magnetic layer having high characteristic coercive force (Hc) can be formed, while reducing the amount of expensive Pt or Ru required.

Abstract: A magnetic recording medium comprises a nonmagnetic substrate on which is disposed at least a vertical magnetic layer. The vertical magnetic layer comprises at least three layers including a lower layer, an intermediate layer and an upper layer from the substrate side. The lower, intermediate and upper magnetic layers are bound by ferro-coupling and are constituted of magnetic particles which are columnar crystals extending continuously from the lower layer to the upper layer. A nonmagnetic layer is between the lower and intermediate magnetic layers or between the intermediate and upper magnetic layers. The upper layer has a magnetic anisotropic constant (Ku) from 0.8×106 to 4×106 (erg/cc), the intermediate layer has a magnetic anisotropic constant (Ku) from 2×106 to 7×106 (erg/cc) and the lower layer has a magnetic anisotropic constant (Ku) from 1×106 to 4×106 (erg/cc).

Abstract: A magnetic disk includes a substrate, a soft magnetic underlayer disposed over the substrate, and a media layer disposed over the underlayer. The underlayer includes a first plurality of layers each containing NiFe having an atomic concentration of iron that is at least about thirty percent. The underlayer further includes a second plurality of layers that is interleaved with the first plurality of layers. The second plurality of layers each contain FeCoN having an atomic concentration of iron that is greater than an atomic concentration of cobalt, and having an atomic concentration of nitrogen that is less than the atomic concentration of cobalt. The atomic concentration of nitrogen is less than eight percent. The media layer contains a magnetically hard material having an easy axis of magnetization oriented substantially perpendicular to both the media layer and the underlayer.

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: According to one embodiment, a magnetic recording medium includes a magnetic recording layer formed above a substrate, comprising: a first magnetic layer formed from a [Co/Pt]n multilayered film, wherein the first magnetic layer has a face-centered cubic (fcc) (111) crystal structure, the (111) direction being perpendicular to a film surface thereof, and a second magnetic layer comprising a CoCrPt or CoCrPt alloy film formed above the first magnetic layer, wherein the second magnetic layer has a hexagonal close packed (hcp) (00.1) crystal structure, the (00.1) direction being perpendicular to a film surface thereof. According to another embodiment, a system includes a magnetic recording medium as described above, a magnetic head for reading from and/or writing to the magnetic recording medium, a magnetic head slider for supporting the magnetic head, and a control unit coupled to the magnetic head for controlling operation of the magnetic head.

Abstract: Perpendicular magnetic recording (PMR) media and methods of fabricating PMR media are described. The PMR media includes, among other layers, an underlayer, a first onset layer on the underlayer, a second onset layer on the first onset layer, and a perpendicular magnetic recording layer on the second onset layer. The second onset layer has a magnetic moment which is higher than both a magnetic moment of the first onset layer and a magnetic moment of the perpendicular magnetic recording layer.

Abstract: The recording medium according to the invention has a magnetic recording layer, an exchange coupling layer and an enhancement or bias layer with an anisotropy orthogonal to the recording layer. The enhancement layer is designed to have no significant remanent magnetization and preferably to saturate under the write head. The enhancement layer creates an exchange field normal to the anisotropy of the recording layer and has the effect of rotating the magnetization of the recording layer and lowering the required switching field, i.e., the coercivity. The invention can be embodied in a longitudinal recording medium or a perpendicular recording medium. The exchange coupling can either ferromagnetic or antiferromagnetic. The bias layer has a high KuV and anisotropy and is designed to have high thermal stability and minimize the rotation of magnetization with the head field.

Abstract: Embodiments of the present invention help to provide a discrete track medium for realizing a high track density in a low price by adopting a configuration, in which filling of a non-magnetic material into a guard band portion and smoothing processing of a medium surface are not required. According to one embodiment, a perpendicular magnetic recording medium, on the non-magnetic substrate, includes at least: a soft magnetic underlayer; a first recording layer including a crystal grain having a magnetic property and a non-magnetic grain boundary having an oxide, as a main component, surrounding the crystal grain; a second recording layer containing a ferromagnetic metal as a main component and not containing an oxide; and at least one non-magnetic layer provided between the first recording layer and the second recording layer.

Abstract: A perpendicular magnetic recording medium adapted for high recording density and high data recording rate comprises a non-magnetic substrate having at least one surface with a layer stack formed thereon, the layer stack including a perpendicular recording layer containing a plurality of columnar-shaped magnetic grains extending perpendicularly to the substrate surface for a length, with a first end distal the surface and a second end proximal the surface, wherein each of the magnetic grains has: (1) a gradient of perpendicular magnetic anisotropy field Hk extending along its length between the first end and second ends; and (2) predetermined local exchange coupling strengths along the length.

Abstract: Embodiments of the present invention provide a perpendicular magnetic recording media having excellent resolution, signal to noise ratio (S/N), and a small adjacent track erasure. According to one embodiment, underlayers for controlling the orientation and segregation of a magnetic layer, a magnetic layer including an oxide and an alloy of magnetic materials mainly composed of Co, Cr, and Pt, and a ferromagnetic-metal layer which does not contain oxygen, are formed over a substrate. The magnetic layer has at least two layers including ferromagnetic grains and oxides, a first magnetic layer, which is the part of the magnetic layer closer to the substrate, has grain boundaries mainly composed of Cr oxide and at least one oxide selected from Si, Ti, Nb, and Ta, and grain boundaries of a second magnetic layer at the ferromagnetic-metal layer side includes at least one oxide selected from Si, Ti, Nb, and Ta in which Cr oxide is less than the first magnetic layer.

Abstract: Perpendicular recording media with sublayers of dual oxide dopant magnetic materials are disclosed. The magnetic layer may comprise multiple sublayers of magnetic materials. In each sublayer, dual oxide dopants are incorporated. The compositions of the sublayers can be the same or different depending on the application. The magnetic layer may be deposited using a target comprising a mixture of CoPtCrB and dual oxides as dopants. The layer deposited with such targets can be the entire magnetic layer or a sublayer.

Abstract: The invention provides a perpendicular recording medium with high recording density, and a magnetic recording and reproducing apparatus, by improving the function of magnetic anisotropy of a soft magnetic underlayer. The perpendicular recording medium has at least a soft magnetic underlayer and a perpendicular magnetic recording layer on a non-magnetic substrate, wherein when Ku? (erg/cm3) is defined as a perpendicular magnetic anisotropic energy, and Ms (emu/cm 3) is defined as a saturation magnetization of the soft magnetic underlayer, Ku? of the soft magnetic underlayer has a negative value and Ku?<?2?Ms2. As a result, the easy axis of a magnetization of a soft magnetic underlayer is oriented strongly in the substrate surface plane, which is effective to suppress the WATE phenomena and spike noise.

Abstract: In one embodiment, a magnetic recording medium comprises an underlying film, a magnetic film and a protective film formed in this order on a substrate. The magnetic film is a cobalt-base alloy film containing chromium and has a plurality of magnetic layers stacked without interposition of any non-magnetic layer. The plural magnetic layers comprise first, second and third magnetic layers. The first magnetic layer is disposed between the underlying film and the second magnetic layer. The second magnetic layer is disposed between the first magnetic layer and the third magnetic layer. The third magnetic layer is disposed between the second magnetic layer and the protective film. The concentration of chromium contained in the first magnetic layer is lower than that of chromium contained in the second magnetic layer. The thickness of the first magnetic layer is smaller than that of the second magnetic layer. The magnetic layers which overlie the first magnetic layer further contain platinum and boron.

Abstract: A magnetic-recording medium which is provided on a nonmagnetic substrate with at least an orientation-controlling layer for controlling the orientation of a layer formed directly thereon, a perpendicularly magnetic layer having an easily magnetizing axis oriented mainly perpendicularly relative to the nonmagnetic substrate, and a protective layer. The perpendicularly magnetic layer includes two or more magnetic layers, at least one of the magnetic layers is a layer having Co as a main component and containing Pt as well and containing an oxide, and at least another of the magnetic layers is a layer having Co as a main component and containing Cr as well and containing no oxide.

Abstract: An improved structure for the construction of perpendicular recording media is disclosed. The structure includes a perpendicular recording layer with at least two oxide sublayers or a lower sublayer of a non-oxide. One structure includes an upper sublayer comprised of a Silicon-oxide, while a lower sublayer is comprised of a Tantalum-oxide. The structures provide for increased coercivity and corrosion resistance.

Abstract: Embodiments of the present invention provide a magnetic disk drive capable of allowing higher data transfer rates and higher recording densities. According to one embodiment, an upper magnetic core and lower magnetic core comprise a multi-layered magnetic film formed by alternately stacking a face-centered cubic (fcc) crystalline magnetic thin layer and a body-centered cubic (bcc) crystalline magnetic thin layer by plating. The plating bath is such that the temperature is about 30±1° C., pH is about 2.0?1.0 to 2.0+0.5, metal ion concentrations are about 5 to 25 (g/l) for Ni2+ and 5 to 15 (g/l) for Fe2+, saccharin sodium concentration is about 1.5±1.0 (g/l), sodium chloride concentration is about 25±5 (g/l), and boric acid concentration is about 25±5 (g/l). Since each layer's crystal structure is different from that of its adjacent lower layer, epitaxial growth is broken within each layer.

Abstract: A novel heat assisted magnetic recording (HAMR) medium and the fabrication method therefor are provided. The exchange coupling effect occurring at the interface of FePt/CoTb double layers is adopted, and thus the resulting magnetic flux would be sufficient enough to be detected and readout under the room temperature. The provided HAMR medium exhibits a relatively high saturation magnetization and perpendicular coercivity, and thus possesses a great potential for the ultra-high density recording application.

Abstract: An improved structure for the construction of perpendicular recording media is disclosed. The structure includes a tri-layer IML resident between a soft under layer CoTaZr film and a CoPtCr—SiO2 magnetic media. In an embodiment, the tri-layer comprises a RuxCr1?x layer over dual nucleation layers of Ni—Fe and Ni—Fe—Cr. The tri-layer replaces the typical Ru and Ni—Fe intermediate layers of the prior art, resulting in considerable improvement in lattice matching between the Ru containing intermediate layer and the CoPtCr—SiO2 magnetic media, further resulting in improved magnetic media performance.

Abstract: A thermally assisted magnetic recording system is provided to achieve excellent thermal resistance and low noise. In one embodiment, a magnetic recording medium is used, in which the magnetic intergrain exchange coupling is large to let the magnetization be thermally stable by coupling the magnetic grains constituting the recording layer at room temperature (the temperature maintaining the magnetization) and reduced by heating during recording to let the recording magnetization transition slope become steep. Parameter A normalizing the slope around the coercivity of the MH-loop of the medium is 1.5?A<6.0 at room temperature, and it becomes approximately 1.0 with heating.

Abstract: One inventive aspect relates to a high-frequency magnetic thin film capable of working in a GHz-level band, and an electronic device comprising the film. The film comprises a magnetic layer and an insulating layer that are laminated alternately. The magnetic layer includes a first magnetic layer and a second magnetic layer. The first magnetic layer has a higher anisotropic magnetic field than the second magnetic layer, and the second magnetic layer has a higher saturation magnetization than the first magnetic layer.

Abstract: A perpendicular magnetic recording medium including a soft magnetic underlayer. The perpendicular magnetic recording medium includes: a lower structural body including an anti-ferromagnetic layer; a first soft magnetic underlayer, a non-magnetic layer, and a second soft magnetic underlayer sequentially formed on the anti-ferromagnetic layer, where the thickness ratio of the second soft magnetic underlayer to that of the first soft magnetic underlayer is designed to be within specific range; and a recording layer formed on the second soft magnetic underlayer. Therefore, noise generated on the soft magnetic underlayer due to external magnetic fields of a magnetic head and a voice coil motor can be reduced greatly.

Abstract: A magnetic storage medium includes a substrate, a first magnetic layer film that is deposited on the substrate, and a second magnetic layer film that is a cap layer of the first magnetic layer film. The first magnetic layer film contains a high magnetic anisotropic material and a low-temperature diffusion material which is added to the high magnetic anisotropic material, the low-temperature diffusion material starting diffusion by thermal treatment at a lower temperature than that of the high magnetic anisotropic material. The second magnetic layer film includes a material for promoting diffusion of the low-temperature diffusion material.

Abstract: A magnetic recording medium having a Au, Ag-containing magnetic layer having Co, Cr, Ag and Au; the magnetic recording layer having Co-containing magnetic grains surrounded by substantially nonmagnetic Cr-containing grain boundaries; wherein said Ag and said Au are substantially immiscible in the Co-containing magnetic grains is disclosed.

Abstract: A granular perpendicular magnetic recording medium comprises a non-magnetic substrate and a granular perpendicular magnetic recording layer overlying the substrate, comprising a first granular perpendicular magnetic layer proximal the substrate and having a first saturation magnetization (Ms)1, and a second granular perpendicular magnetic layer distal the substrate and having a second, different saturation magnetization (Ms)2. Also disclosed is a method of fabricating the granular perpendicular magnetic recording medium.

Abstract: A magnetic recording medium with a granular magnetic recording layer excellent in corrosion resistance is provided. In one embodiment, after formation of, on a non-magnetic substrate, an NiTa adhesion layer, a soft magnetic layer, a Ta intermediate layer, an Ru intermediate layer, and a Co alloy granular magnetic recording layer, hydrogen (H2) plasma processing is applied to the surface of the Co alloy granular magnetic recording layer. Then, a DLC protective film layer is formed and a lubricant layer is coated.

Abstract: A bit error rate is improved and, at the same time, an aging change due to thermal fluctuation is decreased. In one embodiment, a magnetic recording medium has first, second, third, and fourth magnetic layers stacked over the underlayer film on a substrate. The product (Brt2) of the residual magnetic flux density and film thickness of the second magnetic layer is smaller than the product (Brt3) of the residual magnetic flux density and film thickness of the third magnetic layer. The second magnetic layer has a thickness larger than that of the third magnetic layer and is anti-ferromagnetically coupled with the first magnetic layer by way of the first non-magnetic intermediate layer. The fourth magnetic layer is formed by way of a second non-magnetic intermediate layer above the third magnetic layer.

Abstract: A corrosion-resistant granular magnetic recording medium with improved recording performance comprises a non-magnetic substrate having a surface; and a layer stack on the substrate surface, including, in order from the surface: a granular magnetic recording layer; an intermediate magnetic de-coupling layer; and a corrosion preventing magnetic cap layer. The intermediate magnetic de-coupling layer has an optimal thickness and/or composition for: (1) promoting magnetic exchange de-coupling between the granular magnetic recording layer and the magnetic cap layer; and (2) reducing the dynamic closure field (Hcl) for determining writeability and eraseability of the medium. Grain boundaries of the magnetic cap layer are substantially oxide-free, and have a greater density and lower average porosity and surface roughness than those of the granular magnetic recording layer.

Abstract: Embodiments of the present invention help to provide an excellent perpendicular recording medium of high medium signal-to-noise (S/N) and with suppressed blurring in writing. According to one embodiment, a perpendicular recording layer is provided by way of a negative magnetic strain soft-magnetic underlayer above a substrate applied with texturing in the circumferential direction. The soft-magnetic underlayer has a first soft magnetic layer, a second soft magnetic layer and a nonmagnetic magnetic layer formed between the first soft magnetic layer and the second soft magnetic layer in which the first soft magnetic layer and the second soft magnetic layer are antiferromagnetically coupled to each other and the easy magnetization axis is directed in the radial direction.

Abstract: A perpendicular magnetic recording medium is provided, which has a backing layer, a primer layer, an intermediate layer and at least one perpendicular magnetic recording layer, and is characterized in that the perpendicular magnetic recording layer contains Co and Cr, and at least one of the perpendicular magnetic recording layer or layers has a granular structure comprising ferromagnetic crystal grains and grain boundaries comprised of non-magnetic tungsten oxide. The perpendicular magnetic recording layer may be a double-layered structure comprising the tungsten oxide grain boundary-containing layer and a Cr oxide, Si oxide, Ta oxide or Ti oxide grain boundary-containing layer formed on the tungsten oxide grain boundary-containing layer. The perpendicular magnetic recording medium exhibits good perpendicular orientation and has ferromagnetic crystal grains with extremely small grain size, and thus, is superior in high recording density characteristic.

Abstract: A recording medium providing improved writeability in perpendicular recording applications includes a magnetic recording layer having an axis of magnetic anisotropy substantially perpendicular to the surface thereof, an exchange-spring layer ferromagnetically exchange coupled to the magnetic recording layer and having a coercivity less than the magnetic recording layer coercivity, and a coupling layer between the magnetic recording layer and the exchange-spring layer. The coupling layer regulates the ferromagnetic exchange coupling between the magnetic recording layer and the exchange-spring layer.

Abstract: Perpendicular magnetic recording media has been enhanced by controlling the initial growth of magnetic oxide layers and increased magnetic isolation between the grains in the initial magnetic layer. An onset magnetic oxide layer is sputter deposited in an argon-oxygen gas mixture between the main CoPtCr-oxide magnetic layers and the underlying Ru layer. The insertion of the onset magnetic oxide layer enhances the coercivity of the oxide magnetic layers and also improves the nucleation field. The media signal-to-noise ratio and bit error rate also are significantly improved due to the improvement of the initial segregation of Co magnetic grains in the magnetic oxide layers.

Abstract: A thin film structure comprises a first layer including a first plurality of grains of magnetic material having a first intergranular exchange coupling, and a second layer positioned adjacent to the first layer and including a second plurality of grains of magnetic material having a second intergranular exchange coupling, wherein the second intergranular exchange coupling is larger than the first intergranular exchange coupling and wherein the Curie temperature of the first layer is greater than the Curie temperature of the second layer. A data storage system including the thin film structure is also provided.

Abstract: A magnetic thin line includes a first magnetic film having in-plane magnetic anisotropy and a second magnetic film that is magnetically coupled to the first magnetic film and has perpendicular magnetic anisotropy. With the coupling of the first magnetic film and the second magnetic film, magnetic wall width of the first magnetic film is lower than a case where the first magnetic film is not magnetically coupled to the second magnetic film.