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 method for manufacturing discrete track media and patterned media is disclosed which enables a magnetic recording layer having excellent magnetic characteristics to be obtained without imparting damage to a crystal orientation control layer which is at the surface when forming the magnetic recording layer. The method for manufacturing magnetic recording media comprises a process of forming a soft magnetic layer on a substrate; a process of forming a first crystal orientation control layer on the soft magnetic layer; a process of providing a depression in at least a portion of the first crystal orientation control layer; a process of performing heat treatment of the first crystal orientation control layer; and a process of forming a magnetic recording layer on the first crystal orientation control layer.

Abstract: A manufacturing method for a magnetic recording medium includes forming a magnetic layer on a base material, forming a recording layer having a textured pattern of the magnetic layer by forming a recessed portion that passes through the magnetic layer, depositing an oxidizing material or a nitriding material on the inner surface of the recessed portion while leaving a space in the recessed portion, packing the space with an oxide material or a nitride material by oxidizing or nitriding the deposited material, and planarizing by removing excess oxide material or nitride material on the recording layer.

Abstract: Embodiments of the present invention provide a perpendicular magnetic recording medium which does not cause medium noise to increase due to soft magnetic underlayers, is capable of easily controlling the thickness of a nonmagnetic layer disposed between soft magnetic underlayers, and capable of improving the corrosion resistance of the soft magnetic underlayers. According to one embodiment, in a perpendicular magnetic recording medium, an adhesion layer is formed on a substrate, a soft magnetic underlayer is formed on the adhesion layer, a seed layer and an intermediate layer are formed above the soft magnetic underlayer, and a perpendicular layer is formed on the intermediate layer.

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: 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 includes at least a soft-magnetic underlayer, a non-magnetic underlayer, a ferromagnetic intermediate layer, a non-magnetic intermediate layer, and a perpendicular magnetic recording layer sequentially stacked on a non-magnetic substrate. In an embodiment, the ferromagnetic intermediate layer is formed of a CoCr based alloy, a product Bs·t of a saturation magnetic flux density and film thickness of the ferromagnetic intermediate layer is within a range of 0.15 to 3.6 T·nm, and the non-magnetic intermediate layer has a film thickness of 3 nm or more.

Abstract: According to one embodiment, a perpendicular magnetic recording layer comprises a granular film type recording layer and a continuous film type recording layer. The granular film type recording layer comprises a first granular film type recording layer in which magnetic crystal grains in a film plane has an average crystal grain diameter of 3 to 7 nm, and a second granular film type recording layer including magnetic crystal grains having an in plane average crystal grain diameter larger than that of the magnetic crystal grains of the first granular film type recording layer.

Abstract: A magnetic recording medium that is capable of realizing both high magnetic permeability and antiferromagnetic coupling for a soft magnetic underlayer. Namely, a magnetic recording medium including at least a non-magnetic substrate on which is laminated a soft magnetic underlayer formed by antiferromagnetic coupling of a plurality of soft magnetic layers, and a perpendicular magnetic layer for which the axis of easy magnetization is oriented mainly perpendicularly to the non-magnetic substrate, wherein the soft magnetic layers contain Fe as a first main component, Co as a second main component, and also contain Ta, the soft magnetic underlayer is antiferromagnetically coupled using the second peak or a subsequently appearing peak of the antiferromagnetic coupling force, which changes according to the thickness of a spacer layer sandwiched between the plurality of soft magnetic layers, and the magnetic permeability of the soft magnetic underlayer is not less than 1,000 H/m.

Abstract: An object of the present invention is to provide a perpendicular magnetic recording medium the SNR of which is improved by reducing noise thought to be due to an auxiliary recording layer so that a higher recording density can be achieved, and a method of manufacturing the same. In order to achieve the above object, a representative configuration of a perpendicular magnetic recording medium 100 according to the present invention includes, on a base, at least a magnetic recording layer 122 having a granular structure in which a non-magnetic grain boundary portion is formed between crystal particles grown in a columnar shape; a non-magnetic split layer 124 disposed on the magnetic recording layer 122 and containing Ru and oxygen; and an auxiliary recording layer 126 that is disposed on the split layer 124 and that is magnetically approximately continuous in an in-plane direction of a main surface of the base 110.

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: A magnetic disk 10 for use in perpendicular magnetic recording, which includes an underlayer 18, a size-reduction promoting layer 20 (nonmagnetic granular layer) of a granular structure, and a magnetic recording layer 22 having a ferromagnetic layer 32 of a granular structure. The size-reduction promoting layer 20 has an inorganic oxide matrix and nonmagnetic metal crystal grains and is disposed between the underlayer 18 and the ferromagnetic layer 32, thereby reducing the size of magnetic crystal grains in the ferromagnetic layer 32.

Abstract: Spin-transfer torque memory having a compensation element is disclosed. A spin-transfer torque memory unit includes a free magnetic layer having a magnetic easy axis and a magnetization orientation that can change direction due to spin-torque transfer when a write current passes through the spin-transfer torque memory unit; a reference magnetic element having a magnetization orientation that is pinned in a reference direction; an electrically insulating and non-magnetic tunneling barrier layer separating the free magnetic layer from the magnetic reference element; and a compensation element adjacent to the free magnetic layer. The compensation element applies a bias field on the magnetization orientation of the free magnetic layer. The bias field is formed of a first vector component parallel to the easy axis of the free magnetic layer and a second vector component orthogonal to the easy axis of the free magnetic 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: The invention includes a disk drive with a magnetic recording disk with an upper and lower sublayer in at least one magnetic layer of a laminated magnetic layer structure that includes a spacer layer that substantially decouples the magnetic layers. The lower sublayer has a lower boron content than the upper sublayer and a preferred embodiment is CoPtCrBTa. The upper sublayer is deposited onto the lower sublayer and is preferably CoPtCrB with a higher boron content than the lower sublayer. The composition of the lower sublayer gives it a very low moment with low intrinsic coercivity which would not be useful as a recording layer on its own. The upper sublayer is a higher moment alloy with high intrinsic coercivity. An embodiment of the invention includes a laminated magnetic layer structure which is antiferromagnetically coupled to a lower ferromagnetic layer.

Abstract: The invention uses an adhesion layer of an amorphous alloy of aluminum. A first aluminum titanium embodiment of the amorphous adhesion layer preferably contains approximately equal amounts of aluminum and titanium (+/?5 at. %). A second embodiment of the amorphous adhesion layer preferably contains approximately equal amounts of aluminum and titanium (+/?5 at. %) and up to 10 at. % Zr with 5 at. % Zr being preferred. A third embodiment is aluminum tantalum preferably including from 15 to 25 at. % tantalum with 20 at. % being preferred. The most preferred compositions are Al50Ti50, Al47.5Ti47.5Zr5 or Al80Ta20. The adhesion layer is deposited onto the substrate. The substrate can be glass or a metal such as NiP-plated AlMg. The preferred embodiment of media according to the invention is for perpendicular recording and includes a magnetically soft underlayer deposited above the adhesion layer.

Abstract: A spin-valve element has a pair of ferromagnetic layers having mutually different coercive forces, sandwiching an insulating layer or a nonmagnetic layer therebetween. The in-plane shape of the spin-valve element is substantially circular in shape but is provided, in the peripheral portion, with a plurality of cutouts NS, NW, NE, NN. Preferably, the shape of at least one cutout be made different from that of others. Moreover, a storage device that employs such a spin-valve element is provided.

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 domain wall motion element has a magnetic recording layer 10 that is formed of a ferromagnetic film and has a domain wall DW. The magnetic recording layer 10 has: a pair of end regions 11-1 and 11-2 whose magnetization directions are fixed; and a center region 12 sandwiched between the pair of end regions 11-1 and 11-2, in which the domain wall. DW moves. A first trapping site TS1 by which the domain wall DW is trapped is formed at a boundary between the end region 11-1, 11-2 and the center region 12. Furthermore, at least one second trapping site TS2 by which the domain wall DW is trapped is formed within the center region 12.

Abstract: An object of the present invention is to provide a perpendicular magnetic recording medium capable of reducing noise in an electromagnetic transducing characteristic in a configuration including a magnetic recording layer of a granular structure containing Co and an auxiliary recording layer. The perpendicular magnetic recording medium of the present invention includes: on a non-magnetic substrate, a first magnetic recording layer 20a of a granular structure in which a non-magnetic grain boundary part is provided between magnetic grains in a columnar shape containing at least Co; a non-magnetic layer 22 provided on the first magnetic recording layer 20a; a second magnetic recording layer 20b of a granular structure in which a non-magnetic grain boundary part is provided between magnetic grains in a columnar shape containing Co provided on the non-magnetic layer 22; and an auxiliary recording layer 24 provided on the second magnetic recording layer 20b.

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 magnetic recording medium is formed by stacking in order, on a nonmagnetic base, at least an underlayer, magnetic recording layer, and protective layer. The magnetic recording layer includes a plurality of magnetic layers and an exchange-coupling control layer, and the magnetic recording medium is characterized in that a physical pattern is formed in the exchange-coupling control layer. The exchange-coupling control layer is located between the magnetic layers of the magnetic 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: A method and apparatus for writing magnetization states in a pair of magnetic islands of a multi-level patterned magnetic recording medium and a method and apparatus for reading readback waveforms representing the written magnetization states of a pair of magnetic islands of a two-level patterned magnetic recording medium. Writing each magnetization state includes selecting the magnetization state, determining a write current sufficient to write the magnetization state, and applying the write current to a magnetic write head to write the magnetization state by simultaneously writing associated magnetic states in each magnetic island of the pair of magnetic islands. Reading the readback waveform representing the written magnetization state is implemented through use of a magnetic read head and includes: identifying the written magnetization state by decoding the readback waveform; and displaying and/or recording the written magnetization state.

Abstract: Embodiments of the invention provide a perpendicular magnetic recording medium improved for fly ability, high in read signal quality, and capable of suppressing magnetic decay of recorded magnetization to be caused by stray fields. In one embodiment, a perpendicular recording layer is formed over a substrate with a soft magnetic underlayer therebetween, then an amorphous or nano-crystalline layer is formed between the substrate and the soft magnetic underlayer. The soft magnetic underlayer includes first and second amorphous soft magnetic layers, as well as a nonmagnetic layer formed between those first and second amorphous soft magnetic layers. The first and second amorphous soft magnetic layers are given uniaxial anisotropy in the radial direction of the substrate respectively and coupled with each other antiferromagnetically.

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: A perpendicular magnetic recording medium, usable for either continuous or patterned media, has a recording layer structure (RLS) of first and second perpendicular magnetic layers (PM1, PM2) and an antiferromagnetically coupling (AFC) layer and a ferromagnetic switching layer (SWL) between PM1 and PM2. The magnetic recording system uses heat to assist in the reading and/or writing of data. The SWL is a Co/Ni multilayer with a Curie temperature (TC-SWL) less than the Curie temperatures of PM1 and PM2. At room temperature, there is ferromagnetic coupling between SWL and the upper ferromagnetic layer (PM2) so that the magnetizations of SWL and PM2 are parallel, and antiferromagnetic coupling between SWL and the lower ferromagnetic layer (PM1) across the AFC layer so that the magnetization of PM1 is aligned antiparallel to the magnetizations of SWL and PM2.

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 perpendicular magnetic recording medium includes a nonmagnetic substrate, and a soft magnetic layer, a first orientation control layer, a second orientation control layer, a nonmagnetic intermediate layer, a magnetic recording layer, and a protective layer layered sequentially on the nonmagnetic substrate. The first orientation control layer includes a thin film having a face-centered cubic (fcc) structure. The magnetic recording layer includes a thin film layer having ferromagnetic crystal grains and nonmagnetic grain boundaries surrounding the ferromagnetic crystal grains, the ferromagnetic crystal grains including a CoPt alloy having ferromagnetic properties, and the nonmagnetic grain boundaries including an oxide or a nitride. The nonmagnetic intermediate layer includes a thin film containing Ru.

Abstract: A perpendicular magnetic recording medium includes a substrate, a soft magnetic layer, a pre-underlayer, an underlayer, and a main recording layer serving as a magnetic recording layer. The pre-underlayer contains seed crystal grains that serve as a base for crystal grains of the underlayer, and an addition substance that is added between the seed crystal grains and composed of an element having an atomic radius smaller than that of an element forming the seed crystal grains.

Abstract: A perpendicular magnetic recording medium, including a soft-magnetic backing layer; and a recording layer provided over the oft-magnetic backing layer. There is provided a magnetic flux slit layer between the soft-magnetic backing layer and the recording layer. The magnetic flux slit layer includes a soft-magnetic layer having a generally columnar structure generally isolated magnetically in an in-plane direction. The magnetic flux slit layer contains at least one selected from the group consisting of Co, Fe, Ni, a Co alloy, a Fe alloy, and a Ni alloy, as a major component, and the magnetic flux slit layer further contains any one selected from the group consisting of Ta, Cu, Pb, Cr, and Re.

Abstract: Multiple anisotropy layered magnetic structures for controlling reversal mechanism and tightening of switching field distribution in bit patterned media are disclosed. The invention extends the exchange spring concept to more variable and sophisticated structures. Three or more layers with different anisotropy or anisotropy gradients increase writeability gains beyond the simple hard/soft bilayer exchange spring concept for BPM. The structures have a thin very hard, high anisotropy center layer that acts as a threshold or pinning layer for domain wall propagation through the entire media structure. In addition or alternatively, a thin very soft, low anisotropy center layer in between the commonly used soft surface layer and hard media layer allows quick initial propagation of the domain wall into the center of the media structure. Various properties of the media structures can be tuned more independently for optimization if using more advanced multi-anisotropy layer stacks.

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: An object of the invention is to provide a magnetic recording medium which exhibits an excellent corrosion resistance. To this end, proposed is a magnetic recording medium including a magnetic recording layer in which: a magnetic body and a filling body alternately appear along a recording surface; and a layer made of a passivated metal or an alloy containing at least one passivated metal is formed in an interface portion between an area of the magnetic body and an area of the filling body.

Abstract: An apparatus and method are provided for improving perpendicular magnetic recording media. The present invention provides media, and a method of fabricating media in a cost-effective manner, with a reduced ruthenium (Ru) content interlayer structure, while meeting media performance requirements. A perpendicular magnetic recording medium is provided comprising a non-magnetic substrate having a surface, and a layer stack situated on the substrate surface. The layer stack comprises, in overlying sequence from the substrate surface a magnetically soft underlayer; an amorphous or crystalline, non-magnetic seed layer; an interlayer structure for crystallographically orienting a layer of a perpendicular magnetic recording material situated on the underlayer; and at least one crystallographically oriented, magnetically hard, perpendicular magnetic recording layer situated on the interlayer structure.

Abstract: A perpendicular magnetic recording medium composed of a nonmagnetic substrate having a surface onto which are provided a plurality of layers including, in the order recited, a soft underlayer; a nonmagnetic coupling layer; a hard magnetic pinning layer which is antiferromagnetically coupled to the soft underlayer at ambient temperature via the nonmagnetic coupling layer and which has an axis of easy magnetization which extends in a direction which is perpendicular to that of the surface of the nonmagnetic substrate; a nonmagnetic intermediate layer; and a magnetic recording layer. Such a perpendicular magnetic recording medium has an improved medium performance, with reduced noise originating from the presence of the soft underlayer, and no erasure of recorded magnetization when influenced by an external magnetic field.

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: One object of the present invention is to provide a method for easily providing an ECC type magnetic recording medium with low cost, which is easily designed, and the present invention provides a perpendicular magnetic recording medium including at least a soft magnetic backing layer, an under layer, an intermediate layer, and a perpendicular magnetic recording layer on a non-magnetic substrate, wherein the perpendicular magnetic recording layer includes at least one of a main recording layer and an auxiliary recording layer, the main recording layer includes a layer having perpendicular magnetic anisotropy, the auxiliary recording layer is a multilayer including three or more of a soft magnetic layer and a non-magnetic layer which are layered alternately, and the outermost layer to the non-magnetic substrate is the soft magnetic layer.

Abstract: A thermal-assist magnetic recording medium is provided which can accomplish a surface recording density of 1 Tbit/inch2. The thermal-assist magnetic recording medium includes: a substrate; a plurality of underlying layers formed on the substrate; a first magnetic layer formed on the underlying layers; a coupling control layer formed on the first magnetic layer and formed of a ferromagnetic alloy; and a second magnetic layer formed on the coupling control layer. Here, Curie temperatures of the first magnetic layer and the second magnetic layer are higher than the Curie temperature of the coupling control layer, an anisotropy magnetic field of the first magnetic layer is greater than the anisotropy magnetic field of the second magnetic layer, and a saturation magnetic field has a minimum value at a temperature of 350° C. or lower.

Abstract: A method for fabricating a patterned recording medium includes providing a workpiece with a non-magnetic substrate and at least one overlying magnetic layer, laminating a thermal insulation barrier partially in a soft under layer of one of the at least one magnetic layers and forming a topographical pattern including a plurality of trenches in the soft under layer. Blocks of track triplets are formed between adjacent trenches that are magnetically and thermally insulated from other adjacent blocks of track triplets.

Abstract: According to one aspect of the present invention, provided is glass for use in substrate for information recording medium, which comprises, denoted as molar percentages, a total of 70 to 85 percent of SiO2 and Al2O3, where SiO2 content is equal to or greater than 50 percent and Al2O3 content is equal to or greater than 3 percent; a total of equal to or greater than 10 percent of Li2O, Na2O and K2O; a total of 1 to 6 percent of CaO and MgO, where CaO content is greater than MgO content; a total of greater than 0 percent but equal to or lower than 4 percent of ZrO2, HfO2, Nb2O5, Ta2O5, La2O3, Y2O3 and TiO2; with the molar ratio of the total content of Li2O, Na2O and K2O to the total content of SiO2, Al2O3, ZrO2, HfO2, Nb2O5, Ta2O5, La2O3, Y2O3 and TiO2 ((Li2O+Na2O+K2O)/(SiO2+Al2O3+ZrO2+HfO2+Nb2O5+Ta2O5+La2O3+Y2O3+TiO2)) being equal to or less than 0.28.

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: Embodiments in accordance with the present invention provide a perpendicular recording medium with low noise and high recording density by reducing the effects from noise generated from the vicinity of the interface with the intermediate layer of the recording layer, in a perpendicular recording medium utilizing a granular recording layer containing oxygen or oxide additive in a cobalt-chromium alloy formed on an intermediate layer with a ruthenium or ruthenium alloy layer. A first recording layer and a second recording layer are formed in order on an intermediate layer of ruthenium or ruthenium alloy. The first recording layer and the second recording layer are comprised of cobalt as the main material in a granular structure containing chromium and oxygen. The saturation magnetization of the first recording layer is lower than the saturation magnetization of the second 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 (PMR) media and methods of fabricating PMR media are described. The PMR media includes, among other layers, a perpendicular magnetic recording layer and a cap layer that are exchange coupled. The magnetic recording layer and the cap layer may be exchange coupled through direct contact, or may be exchange coupled over a coupling layer. In either embodiment, the cap layer is formed from a CoPtCr alloy having a concentration of Cr in the range of about 15-22 at %.

Abstract: A magnetic recording medium having a first magnetic layer, a spacer layer, and a second magnetic layer, in this order, wherein the spacer layer includes a non-magnetic layer and a thickness of the spacer layer is selected to establish anti-ferromagnetic coupling between the first magnetic layer and the second magnetic layer, and a thickness of both the first and second magnetic layers are less than a critical thickness for formation of stripe domains in the magnetic layers is disclosed.