Hitachi Global Storage Technologies Netherlands B.v.

International Business Machines Corporation

Hgst Netherlands, B.v.

Eric Edward Fullerton

David Thomas Margulies

Hoa Van Do

Stefan Maat

Matthew Joseph Carey

Natacha Frederique Supper

Andreas Klaus Berger

Byron Hassberg Lengsfield, Iii

Jeffrey Childress

Olav Hellwig

Mary Frances Doerner

Bruce Alvin Gurney

Hal Jervis Rosen

Manfred Ernst Schabes

Dieter Klaus Weller

Ernesto Esteban Marinero

Jan-Ulrich Thiele

Philip M Rice

Thai Le

Bruce David Terris

Kai Tang

Andreas Moser

Robert Fontana

Jeffrey Scott Lille

Brian Rodrick York

Henry Hung Yang

Stuart Stephen Papworth Parkin

Jean Fompeyrine

Jinshan Li

Yoshihiro Ikeda

James Terrence Olson

Rolf Allenspach

Kentaro Takano

Wen-yaung Lee

Timothy J Moran

Petrus Antonius VanDerHeijden

William G McChesney

Jean Pierre Locquet

Maria Seo

A laminated magnetic recording structure for use in perpendicular or longitudinal recording is described. A small amount of ferromagnetic coupling is added between the two magnetic layers that are sufficiently decoupled to switch independently. In one embodiment the coupling is achieved by doping the spacer layer with a ferromagnetic material. Ruthenium (Ru), which is a preferred nonmagnetic material for spacer layers with cobalt (Co) being the preferred magnetic material. The weak ferromagnetic coupling can also be achieved through the use of platinum, palladium and alloys thereof for the spacer layer without the addition of a ferromagnetic element, but alternatively they can also be doped with ferromagnetic elements. For embodiments for perpendicular recording the spacer layer further can additionally comprise oxides of one or more elements selected from the group consisting of Si, Ta, Ti, Nb, Cr, V and B.

Laminated magnetic thin films for magnetic recording with weak ferromagnetic coupling

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 (MAG), sometimes called the exchange-spring layer (ESL), ferromagnetically coupled to a lower ferromagnetic layer (MAG), sometimes called the media layer (ML). The RL structure may also include a coupling layer (CL) between MAGand MAGthat permits ferromagnetic coupling. The interlayer exchange coupling between MAGand MAGmay 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 MAGand MAGfor mediating intergranular exchange coupling in the ferromagnetic layer or layers with which it is in contact (MAGor MAG). The ferromagnetic alloy in the LCL has significantly greater intergranular exchange coupling than the ferromagnetic alloy with which it is in contact (MAGor MAG).

Patterned perpendicular magnetic recording medium with exchange coupled recording layer structure and magnetic recording system using the medium

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.

Perpendicular recording media having an exchange-spring structure

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.

Disk drive with laminated magnetic thin films with sublayers for magnetic recording

A magnetic recording disk drive has a patterned perpendicular magnetic recording disk of the type that has spaced-apart pillars with magnetic material on their ends and with trenches between the pillars that are nonmagnetic regions. A nonmagnetic capping layer is located in the trenches above the nonmagnetic regions. The substrate has diffusion material in the trenches that when heated will diffuse into the magnetic recording layer material and chemically react with it. The pillars are formed of material that will not diffuse into the recording layer. The recording layer is formed over the entire substrate and a nonmagnetic capping layer that is not chemically reactive with the diffusion material is formed over the recording layer in the trenches. The substrate is annealed to cause the recording layer material in the trenches and the material in the substrate to diffuse into one another and chemically react to render the trenches nonmagnetic. The capping layer suppresses the diffusion of material from the substrate to the surface in the trenches and thus prevents migration of diffusion material to the recording layer material on the ends of the pillars.

Perpendicular magnetic recording disk drive with patterned disk having capping layer for suppression of surface diffusion of trench material

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 (MAGand MAG), each with perpendicular magnetic anisotropy. MAGand MAGmay have a coupling layer (CL) located between them that permits ferromagnetic exchange coupling of MAGwith MAG. The LCL is located either above or below MAGand in direct contact with MAGand mediates an effective intergranular exchange coupling in MAG. The ferromagnetic alloy in the LCL has significantly greater intergranular exchange coupling than the ferromagnetic alloy in MAG, 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. Because the LCL grain boundaries overlay the boundaries of the generally segregated and decoupled grains of MAG, and the LCL and MAGgrains are strongly coupled perpendicularly, the LCL introduces an effective intergranular exchange coupling in the MAG

Perpendicular magnetic recording exchange-spring type medium with a lateral coupling layer for increasing intergranular exchange coupling in the lower magnetic layer

A patterned perpendicular magnetic recording medium of the type that has spaced-apart pillars with magnetic material on their ends and with nonmagnetic trenches between the pillars is made with a method that allows use of a pre-etched substrate. The substrate has a generally planar surface at the trenches and comprises material that when heated will diffuse into the magnetic recording layer material and chemically react with one or more of the elements typically used in the recording layer. The pillars are formed of material that will not diffuse into the recording layer. After the recording layer is formed over the entire substrate so as to cover both the pillar ends and the trenches, the substrate is annealed. This results in the destruction or at least substantial reduction of any ferromagnetism in the recording layer material in the trenches so that the trenches are nonmagnetic. The annealing does not affect the recording layer on the ends of the pillars because the pillars are formed of material that will not diffuse into the recording layer.

Perpendicular magnetic recording system with patterned medium and manufacturing process for the medium

A magnetoresistive sensor having a hard magnetic pinning layer with an engineered magnetic anisotropy in a direction substantially perpendicular to the medium facing surface. The hard magnetic pinning layer may be constructed of CoPt, CoPtCr, or some other magnetic material and is deposited over an underlayer that has been ion beam etched. The ion beam etch has been performed at an angle with respect to normal in order to induce anisotropic roughness for example in form of oriented ripples or facets oriented along a direction parallel to the medium facing surface. The anisotropic roughness induces a strong uniaxial magnetic anisotropy substantially perpendicular to the medium facing surface in the hard magnetic pinning layer deposited there over.

Magnetic read sensor employing oblique etched underlayers for inducing uniaxial magnetic anisotropy in a hard magnetic pinning layer

A patterned perpendicular magnetic recording medium of the type that has spaced-apart pillars with magnetic material on their ends and with trenches between the pillars that are nonmagnetic regions is made with a method that allows use of a pre-etched substrate. A nonmagnetic capping layer is located in the trenches above the nonmagnetic regions. The substrate has diffusion material in the trenches that when heated will diffuse into the magnetic recording layer material and chemically react with it. The pillars are formed of material that will not diffuse into the recording layer. The recording layer is formed over the entire substrate and a nonmagnetic capping layer that is not chemically reactive with the diffusion material is formed over the recording layer in the trenches. The substrate is annealed to cause the recording layer material in the trenches and the material in the substrate to diffuse into one another and chemically react to render the trenches nonmagnetic. The capping layer suppresses the diffusion of material from the substrate to the surface in the trenches and thus prevents migration of diffusion material to the recording layer material on the ends of the pillars.

Perpendicular magnetic recording medium with patterned magnetic islands and nonmagnetic trenches and manufacturing method for suppressing surface diffusion of trench material

Solid-state memories are disclosed that are comprised of cross-point memory arrays. The cross-point memory arrays include a first plurality of electrically conductive lines and a second plurality of electrically conductive lines that cross over the first plurality of electrically conductive lines. The memory arrays also include a plurality of memory cells located between the first and second conductive lines. The memory cells are formed from a metallic material, such as FeRh, having the characteristic of a first order phase transition due to a change in temperature. The first order phase transition causes a corresponding change in resistivity of the metallic material.

Memory array having memory cells formed from metallic material

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-H) 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 Hsubstantially less than the Hof 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 Hvalues of each of the ESLs can be independently varied to optimize the overall recording performance of the medium.

Perpendicular magnetic recording medium with exchange-spring structure having multiple exchange-spring layers and recording system for the medium

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. The effective EBL appears to be magnetically 'thin' during the write process and magnetically &#x201c;thick&#x201d; during the readback process.

Perpendicular magnetic recording medium with improved antiferromagnetically-coupled recording layer

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.

Antiferromagnetically coupled media for magnetic recording with weak coupling layer

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Morgan Hill, CA, United States of America

Eric Edward Fullerton