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.

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: Disclosed is a method for manufacturing a template for a high-density patterned medium and a high-density magnetic storage medium using the same. In the method, magnetic particles are used as a mask and no lithographic process is required.

Abstract: [PROBLEMS] To improve the track density by reducing the track edge noise and sharpening the boundaries of a recording magnetic field by blocking the recording magnetic field spreading outside the recording region in magnetic recording. [MEANS FOR SOLVING PROBLEMS] 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).

Abstract: The invention relates to a perpendicular magnetic recording medium comprising a substrate and a granular magnetic layer comprising ruthenium or ruthenium oxide in the grain boundaries.

Abstract: A perpendicular magnetic recording medium has an “exchange-spring” type magnetic recording layer (RL) with an improved coupling layer (CL). The RL includes the first or lower ferromagnetic layer MAG1, sometimes called the “media” layer, the second or upper ferromagnetic layer MAG2, sometimes called the “exchange-spring” layer, and the intermediate CL that provides ferromagnetic exchange coupling between MAG1 and MAG2. The CL is formed of NiCr or RuCr based alloys, or CoCr or CoCrB alloys with high Cr and/or B content (Cr plus B>about 25 atomic percent), or RuCoCr alloys with low Co content (<about 65 atomic percent). For each CL composition there is a CL thickness range that provides the optimal interlayer exchange coupling between MAG1 and MAG2. The selected CL materials provide an exchange-type perpendicular magnetic recording medium with good magnetic performance, while the relatively high amount of Cr of the CL improves the corrosion resistance 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 base member; an underlayer formed on the base member; a main recording layer formed on the underlayer, and a writing assist layer formed on or under the main recording layer in contact with the main recording layer. The main recording layer has perpendicular magnetic anisotropy with an anisotropic magnetic field of Hk1 and an inclination of a reversal part of a magnetization curve of a1. The writing assist layer has an anisotropic magnetic field of Hk2 and an inclination of a reversal part of a magnetization curve of a2. The anisotropic magnetic fields Hk1 and Hk2 and the inclinations a1 and a2 satisfy Hk1>Hk2 and a2>a1.

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 recording medium including a perpendicular magnetic recording layer and a laminated SUL formed on a substrate is provided. The SUL includes an antiferromagnetic layer interposed between laminated structures including a magnetic layer, a non-magnetic layer and a magnetic layer. The layers may each have a thickness of 20 nm or less and the layers below the antiferromagnetic layer may be thinner than the layers on the antiferromagnetic layer. The laminated structures formed on and below the antiferromagnetic layer have unidirectional magnetic anisotropies set in the opposite radial direction to each other by an exchange bias. As a result, media magnetic domain noise can be diminished.

Abstract: A magnetic disk for information storage that includes a substrate and an information layer for containing information. The information layer includes a upper (e.g., recording) and lower (e.g., stabilizing) layers. The information layer has a remanence-squareness-thickness-product (“Mrt”) that varies radially between first and second disk radii. At least one of the following conditions is true: (i) the information layer has a coercivity that is at least substantially constant between the first and second disk radii; (ii) the lower magnetic layer has a magnetic anisotropy energy of no more than about 1.5×106 erg/cm3; and (iii) the magnetic anisotropy energy of the upper magnetic layer is at least about 150% of the magnetic anisotropy energy of the lower magnetic layer.

Abstract: The invention provides a perpendicular magnetic recording medium for use in a hard disk drive or a similar apparatus, a method for producing the perpendicular magnetic recording medium, and a magnetic recording and reproducing apparatus. The recording medium has excellent recording and reproducing characteristics and includes at least a non-magnetic substrate, an alignment control layer a perpendicular magnetic layer in which easy-magnetization axes are oriented in a direction virtually normal to a substrate, and a protective layer. The perpendicular magnetic layer containing Co as a predominant component, is formed of at least a first perpendicular magnetic layer formed predominantly from a material containing at least Cr, Pt, and a metal oxide or a semiconductor oxide, a second perpendicular magnetic layer formed predominantly from a CoCr alloy, and a third perpendicular magnetic layer formed predominantly from a CoCrPtB-based alloy.

Abstract: A perpendicular magnetic recording system and medium has a multilayered recording layer that includes an exchange-spring structure and a ferromagnetic lateral coupling layer (LCL). The exchange-spring structure is made up of two ferromagnetically exchange-coupled magnetic layers (MAG1 and MAG2), each with perpendicular magnetic anisotropy. MAG1 and MAG2 are either in direct contact with one another or have a coupling layer (CL) located between them. The LCL is located in direct contact with MAG2 and mediates intergranular exchange coupling in MAG2. The ferromagnetic alloy in the LCL has significantly greater intergranular exchange coupling than the ferromagnetic alloy in MAG2, which typically will include segregants such as oxides. The LCL is preferably free of oxides or other segregants, which would tend to reduce intergranular exchange coupling in the LCL.

Abstract: A structure has a substrate and a layer containing a magnetic material dispersed in a nonmagnetic material, the magnetic material being comprised of first crystal particles having an easy magnetization axis crytsllographically oriented in the direction of the normal line of the substrate and forming columns perpendicular to the substrate and second crystal particles having a crystallographic orientation in a direction different from the direction of the crystallographic orientation in the first crystal particles, and the ratio of the second crystal particles to the entire crystal particles in the columns ranging from 10% to 50% by weight.

Abstract: A perpendicular magnetic recording system uses an exchange-spring type of perpendicular magnetic recording medium. The medium has a recording layer (RL) that includes a lower media layer (ML) and a multilayer exchange-spring layer (ESL) above the ML. The high anisotropy field (high-Hk) lower ML and the multilayer ESL are exchange-coupled across a coupling layer. The multilayer ESL has at least two ESLs separated by a coupling layer, with each of the ESLs having an Hk substantially less than the Hk of the ML. The exchange-spring structure with the multilayer ESL takes advantage of the fact that the write field magnitude and write field gradient vary as a function of distance from the write pole. The thicknesses and Hk values of each of the ESLs can be independently varied to optimize the overall recording performance of the medium.

Abstract: A perpendicular magnetic recording disk has an antiferromagnetically-coupled (AFC) recording layer (RL) comprised of lower and upper ferromagnetic layers, each having a hexagonal-close-packed (hcp) crystalline structure and perpendicular magnetic anisotropy, separated by an antiferromagnetically (AF) coupling layer, wherein the lower ferromagnetic layer (LFM) has substantially higher magnetic permeability than the upper ferromagnetic layer (UFM). The AFC RL is located on an actual exchange break layer (EBL) that separates the AFC RL from the disk's soft magnetic underlayer (SUL). The LFM functions as part of an “effective” exchange break layer (EBL) that also includes the actual EBL and the AF-coupling layer, thereby allowing the actual EBL to be made as thin as possible. The hcp LFM promotes the growth of the hcp UFM in the same way the actual EBL does so that its thickness contributes to the thickness necessary to grow the hcp UFM.

Abstract: Embodiments of the present invention help allow accurate control of the magnetization reversal in a magnetic recording layer in small reversal units, whereby high-density recording can be achieved. According to one embodiment, by forming an intermediate layer having a granular structure similar to that of the magnetic recording layer below the magnetic recording layer, a continuous crystal grain boundary is formed at the interface between the magnetic recording layer and the intermediate layer, thereby preventing incomplete formation of the crystal grain boundary found in the initial growth layer of the magnetic recording layer. The intermediate layer comprises a non-magnetic alloy comprising Co and Cr as its main components and an oxide such as Al, Cr, Hf. Mg, Nb, Si, Ta, Ti and Zr. Further, the average content of the oxygen element in the intermediate layer is in the range from 6 at % to 20 at %.

Abstract: An embodiment of the invention is a layered magnetic thin film structure that uses antiferromagnetically coupled (AFC) magnetic layers where the top layer structure consists of an upper magnetic layer that is weakly ferromagnetically coupled via a nonmagnetic or weakly magnetic exchange coupling layer (interlayer) to a ferromagnetic exchange enhancing layer that is in turn, AF coupled to the lower ferromagnetic layer of the AFC structure. Preferred materials for the weak coupling layer include alloys of cobalt such as CoRu, CoBRu and CoCr in which the Co content is below the point at which the material would be ferromagnetic. A second embodiment of the invention is a laminated, AF-coupled media structure. In this structure the lower AFC layer that makes up the lower laminate layer includes: the middle magnetic layer, the weak ferromagnetic coupling layer, and the exchange enhancing layer.

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 perpendicular magnetic recording medium having a good thermal stability and a high recording density is provided. The perpendicular magnetic recording medium includes at least a first and a second perpendicular magnetic recording layer and a substrate supporting the first and the second perpendicular magnetic recording layers. The first and the second perpendicular magnetic recording layers have different physical/magnetic properties and are formed of materials that compensate the different physical/magnetic properties. The first and the second perpendicular magnetic recording layers are selected from a layer for improving perpendicular magnetic anisotropic energy (Ku), a layer for reducing the size of crystal grains, a layer for reducing the size of magnetic domains, a layer for increasing an SNR, a layer for improving signal output, a layer for reducing noise, a layer for improving the uniformity of crystal grain sizes, and a layer for improving the uniformity of magnetic domain sizes.

Abstract: A perpendicular magnetic recording medium having a substrate, an amorphous soft underlayer of thickness 30 nm or greater, and a granular magnetic recording layer for perpendicular recording is disclosed. The granular magnetic recording layer includes a non-magnetic region between magnetic grains, wherein the non-magnetic region includes metal nitride or metal carbide and provides exchange decoupling between the magnetic grains. The perpendicular recording medium of this invention reduces DC noise and increases media signal-to-noise ratio; it reduces surface roughness, which in turn reduces the head-to-media spacing and the head-to-amorphous soft underlayer spacing.

Abstract: A longitudinal magnetic recording medium having a high medium S/N, with no problems in view of the overwrite characteristic, excellent in the bit error rate and sufficiently stable also to thermal fluctuations is provided. In one embodiment, a first underlayer, second underlayer, and a third underlayer are formed on a substrate and, further, a first magnetic layer, a spacer layer including Ru as a main ingredient, a second magnetic layer, and a third magnetic layer are formed in adjacent with each other in this order. The thickness of the second magnetic layer is made larger than the thickness of the third magnetic layer and the total for the concentrations of cobalt and platinum obtained in the second magnetic layer is not more than the total for the concentrations of cobalt and platinum contained in the third magnetic layer.

Abstract: Provided is a magnetic recording medium having less noise and less recording degradation ascribed to “thermal fluctuation”. The magnetic recording medium has a magnetic recording film in which a magnetic region is dispersed in a non-magnetic region. In the magnetic recording medium, the magnetic region includes a hard magnetic layer which is a first magnetic portion made of a hard magnetic material with a coercive force and a soft magnetic layer which is a second magnetic portion made of a soft magnetic material with a coercive force smaller than that of the first magnetic portion, and the hard magnetic layer and the soft magnetic layer are laminated in a direction parallel to a film surface of the magnetic recording film.

Abstract: A perpendicular magnetic recording disk has a soft magnetic underlayer (SUL) that has high corrosion resistance as well as high moment. The material of the SUL is an alloy comprising Co, Fe, X, and Y; where X is Ta or Nb, Y is Zr or Hf, and the combined amount of X and Y present in the alloy is between about 10 and 20 atomic percent. The atomic ratio of Co to Fe in the alloy is between about 90:10 to 10:90, preferably between about 25:75 and 35:65. The SUL may be a single-layer SUL or a multilayer SUL formed of multiple soft magnetic layers separated by an interlayer film or films.

Abstract: Laminated magnetic recording medium with two Co-containing layers separated by a non-magnetic Ru-containing interlayer is stabilized by Ru-containing layer between the recording layers and Co-containing stabilization layers through anti-ferromagnetic coupling. The insertion of Co layer beneath Ru spacer has resulted in increased coupling, and further coupling enhancement is achieved by low pressure process of Co and Ru layers.

Abstract: A perpendicular magnetic recording medium includes a metamagnetic antiferromagnetically-coupled (AFC) layer between the recording layer (RL) and the soft magnetically permeable underlayer (SUL). The metamagnetic AFC layer has essentially no net magnetic moment in the absence of a magnetic field, but is highly ferromagnetic in the presence of a magnetic field above a threshold field. Thus the metamagnetic AFC layer does not contribute to the readback signal during reading, but channels the write field to the SUL during writing because the threshold field is selected to be below the write field. An exchange-break layer EBL is located between the metamagnetic AFC layer and the RL. The metamagnetic AFC layer contains films with a crystalline structure suitable as a growth template for the EBL and RL, so the metamagnetic AFC layer also functions as part of an “effective EBL”, thereby allowing the actual EBL to be made as thin as possible.

Abstract: Embodiments of the present invention provide a perpendicular magnetic recording medium suitable for high density recording. According to one embodiment, a magnetic recording layer comprises four layers in which a first magnetic layer, a magnetic coupling layer, a second magnetic layer, and a third magnetic layer are formed above a substrate. The first magnetic layer and the second magnetic layer are perpendicular magnetization films containing an oxide, and ferromagnetically coupled with each other by way of the magnetic coupling layer, and they are, more preferably, a Co alloy layer containing an oxide. The third magnetic layer is ferromagnetically coupled with the second magnetic layer. The concentration of the oxide contained in the third magnetic layer is lower than the concentration of the oxide in the second recording layer, or the third magnetic layer does not contain the oxide.

Abstract: A perpendicular magnetic recording medium, such as a perpendicular magnetic recording disk, has a magnetic “torque” layer (MTL) that exerts a magnetic torque onto the perpendicular magnetic recording layer (RL) in the presence of the applied perpendicular write field. The MTL thus acts as a write assist layer in reversing the magnetization of the RL. A coupling layer (CL) is located between the MTL and the RL and provides the appropriate ferromagnetic coupling strength between the MTL and the RL.

Abstract: A magnetic recording medium comprising a nonmagnetic substrate, and a soft magnetic layer and a ferromagnetic layer formed in this order on the nonmagnetic layer, in which the ferromagnetic layer has a thickness of from 3 to 150 nm, contains spherical, ellipsoidal or plate-form ferromagnetic particles and a binder, and has an axis of easy magnetization substantially in the vertical direction, and the soft magnetic layer contains spherical or ellipsoidal Fe—Co-containing soft magnetic particles having a saturation magnetization of from 170 to 220 Am2/kg, and a binder.

Abstract: A method and apparatus for improving the signal-to-noise ratio in a longitudinal recording media is disclosed. The apparatus includes a first recording layer of the longitudinal recording media residing at the top of a recording media structure. The first recording layer includes an upper sublayer comprised of a CoPtCrB-based alloy material. The first recording layer also includes a lower sublayer comprised of a CoPtCrB-based alloy material and a middle sublayer comprised of a CoCrB-alloy. The middle sublayer is coupled to the upper sublayer and to the lower sublayer and is substantially thinner than the upper sublayer and the lower sublayer.

Abstract: A magnetic recording medium which is provided on a nonmagnetic substrate 1 with at least an orientation-controlling layer 3 for controlling the orientation of a layer formed directly thereon, a perpendicularly magnetic layer 4 having an easily magnetizing axis oriented mainly perpendicularly relative to the nonmagnetic substrate 1, and a protective layer 5 and characterized in that the perpendicularly magnetic layer 4 includes two or more magnetic layers, that at least one of the magnetic layers is a layer 4a having Co as a main component and containing Pt as well and containing an oxide and that at least another of the magnetic layers is a layer 4b having Co as a main component and containing Cr as well and containing no oxide.

Abstract: A magnetic recording medium having a composite magnetic recording structure comprising the combination of a hard magnetic layer and a metamagnetic layer that possesses a field induced metamagnetic transition characteristic at ambient operating temperature. Under an applied external magnetic field, the metamagnetic layer transitions from an antiferromagnetic state to a ferromagnetic state, and the magnetic field induces magnetization of the metamagnetic layer. The hard magnetic recording layer is magnetically exchange coupled to the magnetized metamagnetic layer. This results in the softening of the coercivity of the overall magnetic recording structure and reduction of the required switching field during data recording. Upon removal of the applied magnetic field, the metamagnetic layer experiences transition back to an antiferromagnetic state and the coercivity of the hard magnetic layer is restored.

Abstract: A longitudinal magnetic recording medium comprising at least four magnetic layers including a substrate, a CoCrTa magnetic intermediate layer on the substrate, wherein the CoCrTa magnetic intermediate layer comprises Cr<16 at % and Ta<6 at %, a first CoCrPtB magnetic layer on the CoCrTa layer, wherein the first CoCrPtB magnetic layer comprises Cr: 10-14%, Pt: 4-8 at %, B: 6-10%, a second CoCrPtB magnetic layer on the first CoCrPtB magnetic layer, and a third CoCrPtB magnetic layer on the second CoCrPtB layer, wherein the third CoCrPtB magnetic layer comprises Cr: 12-16 at %, Pt: 12-16 at %, B: 10-14 at % and has <10 at % Cr than that in the second CoCrPtB magnetic layer is disclosed.

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: A magnetic recording medium includes as formed on a non-magnetic substrate, a seed layer, an underlayer of a bcc structure-having Cr alloy, an interlayer of an hcp structure-having Ru alloy, a lower recording layer of a Co—Cr—Pt—B base alloy, an upper recording layer having the same alloying base components as those of the lower recording layer, a larger B atom concentration and having a larger Co atom concentration to Cr atom concentration ratio, and a protective layer. The lower recording layer includes a first and a second lower recording layer. When the B atom concentration in the first lower recording layer is B1 and that of the second lower recording layer is B2, then B1<B2, and when the Co atom concentration to Cr atom concentration ratio in the first lower recording layer is (Co/Cr)1, and that of the second lower recording layer is (Co/Cr)2, then (Co/Cr)1<(Co/Cr)2.

Abstract: A magnetic recording medium is provided with an exchange layer structure, and a magnetic layer provided on the exchange layer structure. The exchange layer structure includes a ferromagnetic layer and a nonmagnetic coupling layer provided on the ferromagnetic layer, where the ferromagnetic layer and the magnetic layer are exchange-coupled and having mutually antiparallel magnetizations. The ferromagnetic layer and the magnetic layer satisfy a relationship Hc1??Hc2?, where Hc1? denotes a dynamic coercivity of the ferromagnetic layer and Hc2? denotes a dynamic coercivity of the magnetic layer.

Abstract: A carbonic acid ester is provided that is represented by the formula below and has a melting point of no greater than 0° C. (In the formula, R1 and R2 independently denote a saturated hydrocarbon group, R1 is a branched chain, and R2 is a straight or branched chain). There is also provided a magnetic recording medium that includes a non-magnetic support and, above the support, at least one magnetic layer including a ferromagnetic powder dispersed in a binder, the magnetic layer including the carbonic acid ester. Furthermore, there is provided a magnetic recording medium including a support and, above the support, a non-magnetic layer including a non-magnetic powder dispersed in a binder, and above the non-magnetic layer, at least one magnetic layer including a ferromagnetic powder dispersed in a binder, the non-magnetic layer and/or the magnetic layer including the carbonic acid ester.

Abstract: A laminate structure is disclosed comprising multiple ferromagnetic layers achieving incoherent reversal while maintaining good SNR. A high magnetic moment density, low anisotropy field material may form a thin overlayer deposited over a high-anisotropy media layer. The media layer may have a lower magnetic moment density than the overlayer and have decoupled magnetic grains. A coupling layer may be interposed between the overlayer and the media layer to modulate the exchange there between, thereby reducing the pass-through of noise while still promoting incoherent reversal to achieve reduced write energy requirements.

Abstract: A vertical magnetic recording medium includes a substrate, a soft magnetic backing layer formed on the substrate, a magnetic flux confinement layer formed on the soft magnetic backing layer, an intermediate layer formed on the magnetic flux confinement layer, and a recording layer of a vertical magnetization film formed on the intermediate layer. The magnetic flux confinement layer has a plurality of soft magnetic parts each formed along a track region of plural track regions and a non-magnetic parts formed between adjacent track regions. The intermediate layer is formed of a non-magnetic material and is formed so as to cover a surface of the soft magnetic part and the non-magnetic parts.

Abstract: A multilayered ferromagnetic laminate includes a first magnetic film having a cobalt alloy and a second magnetic film having an iron-nitrogen alloy. The films are deposited upon one another and laminated to provide a multilayered film structure having an alternating plurality of the first and second magnetic films. The cobalt alloy may be a cobalt-zirconium-tantalum alloy. The nitrogen is incorporated interstitially in the crystalline structure of the iron of the second magnetic film. The laminate forms the magnetic shields and the write poles of magnetic disk and tape heads. The lamination of the first magnetic film which has high electrically resistive, high mechanical hardness, and high magnetic moment characteristics with the second magnetic film which has lower electrically resistive and very high magnetic moment characteristics yields the laminate which has very high magnetic moment and very hard pole material characteristics and has the ability to write at high frequencies.

Abstract: An antiferromagnetically coupled (AFC) magnetic recording medium with an AFC master layer comprising at least two magnetic layers with the top magnetic layer including copper is described. The slave layer is separated from the master layer structure by a nonmagnetic spacer layer selected to antiferromagnetically couple the layers. The master layer structure according to the invention includes a bottom and top layer of distinct ferromagnetic materials. Preferably, the top layer of the master layer is a cobalt alloy including from 1 to 5 at. % copper with an example being CoPt13Cr20B8Cu2. The AFC magnetic layer structure can be used with a variety of substrates including circumferentially textured glass and NiP/AlMg.

Abstract: Embodiments of the present invention provide a perpendicular magnetic recording medium having an improved writing property due to the exchange spring effect and capable of stable production. According to one embodiment, a perpendicular magnetic recording medium includes a non-magnetic substrate; an adhesion layer; a soft magnetic underlayer; a seed layer; and intermediate layer; a magnetic recording layer at least including a perpendicular recording layer, a writing assist layer, and a magnetic coupling layer disposed between the perpendicular recording layer and the writing assist layer; a protective layer, and a lubrication layer, in which the saturation magnetization of the magnetic coupling layer is lower than the saturation magnetization of the writing assist layer, the saturation magnetization of the magnetic coupling layer is 300 kA/m (300 emu/cc) or lower, and the thickness of the magnetic coupling layer is 1 nm or more and 3 nm or lower.

Abstract: A magnetic recording layer is formed on an auxiliary magnetic layer in a perpendicular magnetic recording medium. The auxiliary magnetic layer has the axis of easy magnetization in the vertical direction perpendicular to the surface of a substrate. The perpendicular magnetic recording medium reliably allows establishment of the magnetization in the auxiliary magnetic layer in the vertical direction. When a magnetic flux flows along the vertical direction perpendicular to the surface of the magnetic recording layer, the magnetic flux flows across the magnetic recording layer in the vertical direction. The magnetization is thus reliably established in the magnetic recording layer in the vertical direction. The magnetic field of a stronger intensity is thus leaked out of the magnetic recording layer in the vertical direction.

Abstract: Improvements to magnetic recording device including magnetic recording media are described. The improvements include the addition of copper to the recording layer as well as improved underlayers. In addition, improved manufacturing processes and magnetic/recording properties for media through heating and oxidation are described.

Abstract: A magnetic recording medium with tuned exchange coupling comprises: (a) a non-magnetic substrate having a surface; and (b) a stack of thin film layers on the substrate surface, including: (i) a compositionally segregated, exchange decoupled magnetic layer with substantially non-magnetic grain boundaries; and (ii) an exchange coupled magnetic layer adjacent to and in direct contact with the exchange decoupled magnetic layer.

Abstract: A perpendicular magnetic recording medium comprises a non-magnetic substrate having a surface; and a plurality of overlying thin film layers forming a layer stack on the substrate surface, the layer stack including a magnetically hard perpendicular magnetic recording layer structure and an underlying soft magnetic underlayer (SUL), the SUL having a thickness of up to about 100 ?. Also disclosed is a data/information recording, storage, and retrieval system comprising the perpendicular magnetic recording medium and a single-pole magnetic transducer head including main and auxiliary poles positioned in spaced adjacency to an upper surface of the layer stack, the single-pole transducer head comprising a front shield adjacent the main pole.

Abstract: A magnetic recording medium having a soft magnetic underlayer structure that includes two soft underlayers is presented. A thick first soft underlayer, disposed on the medium substrate, is made of material which provides a low magnitude of magnetization saturation (Bsat) and high permeability. The first soft underlayer can be formed by plating or high-rate sputtering. The second soft underlayer, which has a lesser thickness than the first soft underlayer, is made of a material which provides a relatively high magnitude of Bsat and low permeability. The second soft underlayer can be formed by low-rate sputtering. The first soft under layer can be isolated from other layers in the medium by an exchange isolation layer. The second soft underlayer can be exchange coupled to a radial exchange pin layer disposed on the exchange isolation layer.

Abstract: A magnetic recording medium includes a substrate having a surface where a texture is formed along a recording direction; a first underlayer formed on the surface of the substrate and made of Cr or CrMn; a second underlayer formed on the first underlayer and made of CrMn; a third underlayer formed on the second underlayer and made of Cr—X1 alloy wherein X1 includes a material selected from the group consisting of Mo, Ti, W, V, Ta, and Nb; and a recording layer formed on the third underlayer and made of a ferromagnetic material whose main ingredient is Co; wherein content of Mn of the second underlayer is greater than content of Mn of the first underlayer if the first underlayer is made of CrMn; and a total of film thicknesses of the first underlayer and the second underlayer is in a range between 2 nm and 7 nm.

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: A perpendicular magnetic recording disk has a granular cobalt alloy recording layer (RL) containing on the “soft” magnetic underlayer (SUL). The SUL is doped with judiciously chosen elements or alloys or is capped or intercalated with said elements or metal alloy layers. The resulting disk and the SUL in particular has good recording properties, improved mechanical strength and improved corrosion resistance over a comparable disk without the doping or thin layers.