Abstract: In a perpendicular magnetic recording medium in which at least a soft magnetic underlayer, an orientation control layer, a magnetic recording layer and a protective layer are formed on a non-magnetic substrate in order from the bottom, the orientation control layer has a laminated structure of two or more layers including an intermediate layer and a seed layer which is disposed closer to the non-magnetic substrate than the intermediate layer. The seed layer includes two or more kinds of elements having a face-centered cubic structure, has face-centered cubic (111) plane crystals oriented in a direction perpendicular to a substrate surface, and has a pseudo-hexagonal structure.

Abstract: A method of fabricating a discrete track magnetic recording media. A base layer is provided onto which repeating and alternating magnetic layer and non-magnetic layers are deposited. The thickness of the magnetic layer corresponds to the width of the track of the recording media. A cylindrical rod can be used as the base layer, such that the alternating magnetic and non-magnetic layers spiraling or concentric layers around the rod. The resulting media layer can be cut or sliced into individual magnetic media or used to imprint other media discs with the discrete pattern of the media layer.

Abstract: An AFC magnetic recording medium having a three-layered ferromagnetic structure capable of reducing noises without deteriorating thermal stability is provided in order to achieve ultra-high recording density.

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: [Object] To achieve a high coercive force (Hc) and low-noise characteristics (high S/N ratio) through realization of both segregation of SiO2 and high perpendicular magnetic anisotropy by providing a two-layer structure having magnetic recording layers with different properties. [Solution] A magnetic disk for use in perpendicular magnetic recording, having at least an underlayer 5, a first magnetic recording layer 6, and a second magnetic recording layer 7 on a substrate in this order. The first magnetic recording layer 6 and the second magnetic recording layer 7 are each a ferromagnetic layer of a granular structure containing a nonmagnetic substance forming grain boundary portions between crystal grains containing at least Co (cobalt). Given that the content of the nonmagnetic substance in the first magnetic recording layer 6 is A mol % and the content of the nonmagnetic substance in the second magnetic recording layer 7 is B mol %, A>B.

Abstract: A perpendicular magnetic recording medium, which includes a nonmagnetic substrate, and a first underlayer in the form of a soft magnetic under-layer (SUL), a second underlayer, an intermediate layer, a magnetic recording layer, a protective layer, and a lubricant layer sequentially laminated on the nonmagnetic substrate. The SUL has a plurality of SUL layers including a type-A SUL layer, a plurality of type-B SUL layers including at least two adjacent type-B SUL layers, and a nonmagnetic metal spacer layer disposed between the two adjacent type-B SUL layers. The type-A SUL layer may include a material selected from Co, Fe and Ni, a material selected from Cr, V and Ti, and a material selected from W, Zr, Ta and Nb. Each of the type-B SUL layers is in antiferromagnetic coupling, and may include a material selected from Co, Fe and Ni, a material selected from Cr, V and Ti, and a material selected from W, Zr, Ta and Nb.

Abstract: A magnetic recording medium A is provided on a non-magnetic substrate with at least a soft under layer a, an under film 5, an intermediate film 6 and a perpendicular magnetic recording film 7. The soft under layer a is a soft magnetic film having an amorphous structure. The under film 5 is formed of an Ni—W alloy. The intermediate film 6 is formed of an Ru alloy. In the Ni—W alloy, the Ni content is 80 atom % or more, and the W content is 20 atom % or less and preferably in the range of 1 atom % to 12 atom %. A magnetic recording and reproducing device 12 equipped with the magnetic recording medium A is excellent in productivity and capable of recording and reproducing information of high density.

Abstract: A perpendicular magnetic recording medium includes a nonmagnetic seed layer, a nonmagnetic intermediate layer provided on the nonmagnetic seed layer, and a perpendicular recording layer provided on the nonmagnetic intermediate layer. The nonmagnetic seed layer includes a first seed layer made of an amorphous material, and a second seed layer provided between the first seed layer and the nonmagnetic intermediate layer and made of a material having a fcc structure. The amorphous material includes at least one element selected from a group consisting of Ta, W, Nb, Mo, Zr and alloys thereof which include at least one of Ta, W, Nb, Mo and Zr as a main component exceeding 50 at. %.

Abstract: A magnetic recording medium is provided with a first magnetic layer, a nonmagnetic coupling layer provided on the first magnetic layer, and a second magnetic layer provided on the nonmagnetic coupling layer. The first and second magnetic layers are exchange-coupled, and have magnetization directions which are mutually parallel in a state where no external magnetic field is applied thereto, and the first magnetic layer switches the magnetization direction thereof before the second magnetic layer in response to a recording magnetic field which switches the magnetization directions of the first and second magnetic layers.

Abstract: A perpendicular magnetic recording medium, comprising a non-magnetic interlayer structure selected from the group consisting of: (1) a structure comprising a layer of a fcc Au-containing non-magnetic material having a <111> preferred growth orientation and a layer of a different material in overlying or underlying contact therewith; (2) a structure comprising, in overlying sequence, a layer of a fcc Au-containing non-magnetic material adjacent a magnetically soft underlayer and having a <111> preferred growth orientation; and n layers of a different fcc non-magnetic material having a <111> preferred growth orientation, where n=1?5; (3) a structure comprising, in overlying sequence, a layer of a fcc Au-containing non-magnetic material adjacent a magnetically soft underlayer and having a <111> preferred growth orientation; and a layer of a hcp non-magnetic material having a <0002> preferred growth orientation; (4) a structure comprising, in overlying sequence, a layer of a fcc A

Abstract: A perpendicular magnetic recording medium includes: a substrate; a soft magnetic film formed on the substrate; a non-magnetic film including an amorphous interlayer formed on the soft magnetic film and made from a metallic material selected from terbium, gadolinium, dysprosium, tantalum, hafnium, and combinations thereof, a buffer layer formed on the amorphous interlayer and having a face-centered cubic structure, and a seed layer formed on the buffer layer and having a hexagonal crystal structure; and a granular magnetic recording film formed on the seed layer.

Abstract: A magnetic recording medium is provided which has good recording/reproducing characteristics with a recording layer divided in a number of recording elements by a predetermined concavo-convex pattern, and a manufacturing method that enables efficient manufacture of such a magnetic recording medium. The magnetic recording medium includes a substrate, a soft magnetic layer formed over the substrate, a recording layer formed over the soft magnetic layer such as to have magnetic anisotropy in a direction perpendicular to surface, and being divided in a number of recording elements by a predetermined concavo-convex pattern, and a non-magnetic intermediate layer formed between the recording layer and the soft magnetic layer. The recording elements are formed to have a predetermined track shape in a data region.

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 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 may have a coupling layer (CL) located between them that permits ferromagnetic exchange coupling of MAG1 with MAG2. The LCL is located either above or below MAG1 and in direct contact with MAG1 and mediates an effective intergranular exchange coupling in MAG1. The ferromagnetic alloy in the LCL has significantly greater intergranular exchange coupling than the ferromagnetic alloy in MAG1, which typically will include segregants such as oxides. The LCL is preferably free of oxides or other non-metallic segregants, which would tend to reduce intergranular exchange coupling in the LCL.

Abstract: A method for defining magnetic domains in a magnetic thin film on a substrate, includes: coating the magnetic thin film with a resist; patterning the resist, wherein areas of the magnetic thin film are substantially uncovered; and exposing the magnetic thin film to a plasma, wherein plasma ions penetrate the substantially uncovered areas of the magnetic thin film, rendering the substantially uncovered areas non-magnetic.

Abstract: According to one embodiment, a magnetic recording medium includes magnetic patterns made of a ferromagnetic recording layer containing Co, and a nonmagnetic layer which separates the magnetic patterns and has a lower Co concentration than the magnetic patterns.

Abstract: It is made possible to provide a patterned perpendicular magnetic recording medium that has smaller write magnetic field and the variation of magnetic characteristics in the bit regions, generates fewer reversed magnetic domains in the position control information regions of the head, and has excellent thermal stability. A patterned perpendicular magnetic recording medium includes: a nonmagnetic substrate; a soft magnetic base layer formed on the nonmagnetic substrate; a nonmagnetic intermediate layer formed on the soft magnetic base layer; and a perpendicular magnetic recording layer formed on the nonmagnetic intermediate layer, and including a stacked structure of a CoPt-based crystalline film having a Pt content in the range of 5 atomic percent to 35 atomic percent and a rare-earth and transition metal alloy amorphous film formed on the CoPt-based crystalline film. The CoPt-based crystalline film and the rare-earth and transition metal alloy amorphous film are exchange-coupled.

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: The exchange coupled film according to the present invention comprises a buffer layer including a laminate in which an amorphous layer and a hafnium layer are laminated in that order, an antiferromagnetic layer laminated on the hafnium layer of the buffer layer via an intermediate layer with a thickness of at least 2 nm, and a pinned magnetic layer laminated on the antiferromagnetic layer.

Abstract: A magnetic recording medium is provided with an hcp Co alloy magnetic layer with the crystallographic c-axes tilted at an angle from a substrate surface and fixed relative to a recording direction. The tilt is induced by epitaxial growth of the hcp Co alloy on an obliquely evaporated nonmagnetic polycrystalline underlayer, so that the magnetic recording medium exhibits thermal stability and improved overwrite with a single pole-type head.

Abstract: A perpendicular magnetic recording medium has an “exchange-spring” type magnetic recording layer (RL) formed of two ferromagnetic layers with substantially similar anisotropy fields that are ferromagnetically exchange-coupled by a nonmagnetic or weakly ferromagnetic coupling layer. Because the write head produces a larger magnetic field and larger field gradient at the upper portion of the RL, while the field strength decreases further inside the RL, the upper ferromagnetic layer can have a high anisotropy field. The high field and field gradient near the top of the RL, where the upper ferromagnetic layer is located, reverses the magnetization of the upper ferromagnetic layer, which then assists in the magnetization reversal of the lower ferromagnetic layer. Because both ferromagnetic layers in this exchange-spring type RL have a high anisotropy field, the thermal stability of the medium is not compromised. The medium shows improved writability, i.e.

Abstract: A magnetoresistive tunnel junction sensor having improved free layer stability, as well as improved free sensitivity. The free layer is constructed to have a low magnetic coercivity which improves free layer sensitivity. The free layer is also constructed to have a negative magnetostriction which improves free layer stability by preventing the free layer from having an easy axis that is oriented perpendicular to die air bearing surface.

Abstract: A media architecture is optimized for discrete track recording. A capped or exchange-spring media uses a thin media structure and incorporates higher moment density magnetic layers. A thin exchange coupling layer is used in conjunction with a cap layer to control the reversal mechanism and exchange. Thus, the exchange coupling layer mediates the interaction between the two outer magnetic layers. The thickness of the exchange coupling layer is tuned by monitoring the media signal-to-noise ratio, track width and bit error rate. The recording performance is enhanced by tuning the intergranular exchange in the system through the use of the high-moment cap as writeability, resolution and noise are improved.

Abstract: A magnetic thin film structure, a magnetic recording medium including the same, and a method of manufacturing the magnetic recording medium are provided. The magnetic recording medium includes an under layer formed of a transition metal nitride on a substrate and a plurality of magnetic dots, which are unit recording regions, formed of a magnetic material having magnetic anisotropy energy between 106 erg/cc and 108 erg/cc.

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: A thin film structure having a magnetic layer and a seed layer positioned adjacent to the magnetic layer is provided. The seed layer includes a L10 structure.

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: Embodiments of the present invention provide a perpendicular magnetic recoding medium capable of decreasing exchange coupling between crystal grains while suppressing increase in the crystal grain size of the magnetic recording layer. According to one embodiment, a perpendicular magnetic recoding medium is formed by stacking a seed layer, an intermediate layer, a magnetic recording layer, and a protecting layer all above a substrate. The magnetic recording layer has a granular structure constituted of a plurality of columnar grains comprising a CoCrPt alloy and a grain boundary containing an oxide.

Abstract: The invention uses an upper and lower magnetic layer of a laminated magnetic layer structure that includes an AF spacer layer that results in weak antiferromagnetic coupling of the magnetic layers that is insufficient to cause either of the layers to switch so that the magnetic orientations of the two ferromagnetic layers remain parallel. An advantage of the invention is that the AF-coupling tends to anti-correlate the noise in the two layers. The weak AF coupling according to the invention is believed to act at the transition boundaries in the media to cause some of the noise domains to be oriented antiparallel and the noise to be less correlated than would be the case without the AF coupling and thereby to achieve improved SNR.

Abstract: A magnetic recording medium used for a hard disc drive and the like, a method of manufacturing the same, and a magnetic storage device. The magnetic recording medium that includes a substrate, a first ferromagnetic layer formed on the substrate, a non-magnetic layer formed on the first ferromagnetic layer and including a ferromagnetic element and a second ferromagnetic layer formed on the non-magnetic layer, wherein the first ferromagnetic layer and the second ferromagnetic layer are magnetically coupled through the non-magnetic layer.

Abstract: Disclosed herein are a dot-patterned structure for magnetic recording bits and a magnetic recording medium provided therewith. The former exhibits high functionality and high performance owing to good crystallinity. The dot-patterned structure is composed of a first layer, which is continuous, and a second layer, which is discrete. The magnetic recording medium having a dot-patterned recording layer is formed by the steps of treating an underlying layer by lithography, thereby forming grooves, filling the grooves by epitaxial growth with the same material as the underlying layer, removing the photoresist used for lithography in a solvent, thereby forming pits, and filling the pits by epitaxial growth with a magnetic film as the recording layer.

Abstract: A laminated film structure is disclosed comprising multiple ferromagnetic layers achieving improved data recording performance. A non-magnetic spacer layer is disposed between an upper ferromagnetic layer and an antiferromagnetic coupled (AFC) structure. The AFC structure is comprised of a ferromagnetic layer and an antiferromagnetic slave layer. The ferromagnetic layer in the AFC structure, referred to as lower ferromagnetic layer, may contain tantalum to promote chromium segregation at the grain boundaries to achieve magnetic decoupling of the grains with relatively thin boundaries, improving medium signal-to-noise ratio while maintaining good thermal stability of the medium. In some embodiments, the interlayer is a five-element alloy such as a CoCrPtBTa alloy.

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: A magnetic recording medium for thermally assisted recording is disclosed which achieves both high density writing and good control of temperature characteristics. The magnetic recording medium for thermally assisted recording comprises an underlayer, a magnetic recording layer, and a protective layer sequentially laminated on a nonmagnetic substrate. The magnetic recording layer has a structure composed of two magnetic layers and an exchange coupling control layer inserted between the magnetic layers, the two magnetic layers being magnetically coupled through the exchange coupling control layer. The coupling energy Jw in the process of writing a signal and the coupling energy Jr in the state of retaining a signal satisfy a relation 0<Jw<Jr.

Abstract: A contact magnetic transfer (CMT) master template with antiferromagnetically-coupled (AF-coupled) magnetic islands is used for transferring a magnetic pattern, such as a servo pattern, to a magnetic recording disk. The template is a rigid or flexible substrate with each magnetic island being two ferromagnetic films antiferromagnetically-coupled by an antiferromagnetically-coupling (AFC) film. In the presence of the applied magnetic field the magnetic moments of the two ferromagnetic films are parallel and substantially identical so they generate a magnetic field that cancels the applied field in the region of the slave disk facing the islands. However, when the applied field is removed, any residual magnetization results in the remanent moments in the two ferromagnetic films being oriented antiparallel as a result of the antiferromagnetic exchange coupling across the AFC film. Thus the islands have no net remanent magnetic moment that can affect the servo pattern transferred to the recording disk.

Abstract: A bit patterned medium in which an exchange coupling layer induces exchange coupling between adjacent bits in order to reduce a switching field difference resulting from different magnetization directions of bits. The exchange coupling layer is disposed either over or under a recording layer having a plurality of bits. The exchange coupling layer induces exchange coupling between a bit which is to be recorded and an adjacent bit and reduces a switching field difference resulting from a difference between the magnetization direction of the bit to be recorded and the magnetization direction of neighboring bits due to an exchange coupling force generated during the exchange coupling.

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 substrate for perpendicular magnetic recording medium 2 is provided with a soft magnetic substrate coat 5. On this soft magnetic substrate coat 5, an anticorrosion coat 5 is formed. The anticorrosion coat 6 is preferably formed so as to completely cover the entire soft magnetic substrate coat 5.

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 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 magnetic random access memory in which a plurality of magnetoresistive elements are laid out in an array, the magnetoresistive element includes a lower ferromagnetic layer, an upper ferromagnetic layer which has a planar shape smaller than a planar shape of the lower ferromagnetic layer, a first nonmagnetic insulating layer which is formed between the lower ferromagnetic layer and the upper ferromagnetic layer, and a first nonmagnetic metal layer which is formed between the first nonmagnetic insulating layer and the upper ferromagnetic layer.

Abstract: A magnetic recording medium including a substrate, a first underlayer provided on the substrate, a first magnetic layer provided on the first underlayer, a nonmagnetic coupling layer provided on the first magnetic layer, and a second magnetic layer provided on the nonmagnetic coupling layer. The first and second magnetic layers are exchange-coupled, and have magnetizations that are mutually antiparallel in a state where no external field is applied to the magnetic recording medium. Additionally, the first underlayer is made of Cr or a Cr alloy each having a bcc crystal structure and including nitrogen, and further wherein the first underlayer has a thickness in a range of 0.5 nm to 6.0 nm.

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 perpendicular magnetic recording medium comprising a substrate, an underlayer, a Ta-containing seedlayer, a magnetic layer, wherein the underlayer comprises a soft magnetic material and the Ta-containing seedlayer is between the underlayer and the magnetic layer, and a process for improving corrosion resistance of the recording medium and for manufacturing the recording medium are disclosed.

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: The thickness of the spacer layer is set in such as way as to obtain the anti-parallel magnetic coupling between two amorphous ferromagnetic layers in the perpendicular medium. When the thickness of the spacer layer is changed, the exchange field shows an oscillatory behavior and the highest values of the exchange fields are obtained at various thicknesses and indicates an anti-parallel exchange between them. A conventional recording medium applies the smallest thickness (1st APS) among the thicknesses corresponding to the exchange field maximum. On the other hand, the present invention applies the second smallest thickness (2nd APS) to obtain larger tolerance of spacer layer thickness and improved writability and enhanced recording performance.

Abstract: Embodiments of the invention provide a perpendicular magnetic recording medium having a granular structured magnetic recording layer including many columnar grains, and grain boundary layers containing oxide, wherein a high medium S/N ratio is obtained while securing head flyability and durability. In an embodiment, the perpendicular magnetic recording medium includes a granular structured magnetic recording layer having many columnar grains, as well as grain boundary layers including oxide respectively. Assuming that the columnar grains are divided equally in the film thickness direction into a protective layer side portion and an intermediate layer side portion, and the diameter of the protective layer side portion is larger than that of the intermediate layer side portion.

Abstract: A novel method of manufacturing a longitudinal granular oxide recording medium is disclosed. The method preferably entails obtaining a non-magnetic substrate, heating the substrate at a temperature T1 that is greater than 150° C., forming a first layer with body-centered cubic atomic structure and with a <200> preferred growth orientation, cooling the substrate to a temperature T2 and forming a second layer comprising a magnetic oxide-containing granular magnetic layer with a hexagonal close packed atomic structure and with a <11-20> preferred growth orientation. The magnetic oxide-containing granular magnetic layer contains magnetic crystal grains that are substantially isolated by an inter-granular region comprising a non-magnetic substance, wherein the non-magnetic substance is preferably an oxide-containing material.

Abstract: A magnetic recording medium having a substrate, underlayer, a low moment stabilizing layer, an antiferromagnetic coupling layer, a low magnetic layer having a magnetic saturation of equal to or less than 250 emu/cm2, and a high moment magnetic layer having a magnetic saturation of more than 250 emu/cm2, in this order, is disclosed. The magnetic recording medium has a weak coupling strength of Jex ?0.05.

Abstract: A magnetic recording disk is patterned into discrete magnetic and nonmagnetic regions with the magnetic regions serving as the magnetic recording data bits. The magnetic recording layer comprises two ferromagnetic films separated by a nonferromagnetic spacer film. The spacer film material composition and thickness is selected such that the first and second ferromagnetic films are antiferromagnetically coupled across the spacer film. After this magnetic recording layer has been formed on the disk substrate, ions are irradiated onto it through a patterned mask. The ions disrupt the spacer film and thereby destroy the antiferromagnetic coupling between the two ferromagnetic films. As a result, in the regions of the magnetic recording layer that are ion-irradiated the first and second ferromagnetic films are essentially ferromagnetically coupled so that the magnetic moments from the ferromagnetic films are parallel and produce a magnetic moment that is essentially the sum of the moments from the two films.