Seagate Technology Incorporated

Hitachi Global Storage Technologies Netherlands B.v.

Hgst Netherlands, B.v.

Maxtor Corporation

Gunn Choe

B Ramamurthy Acharya

Yoshihiro Ikeda

E Noel Abarra

Jianing Zhou

Kai Tang

Min Zheng

Mohammad Taghi Mirzamaani

Jinliu Wang

Masayoshi Shimizu

Kiwamu Tanahashi

Mingjun Yu

A magnetic media having a novel cap layer that allows the cap layer having improved exchange coupling and reduced thickness. The cap layer is doped with a non-reactive element such as Ar, Kr, Xe, Ne or He preferably Ar. This doping reduces increases exchange coupling and reduces the dead layer, allowing the cap layer to be made thinner for reduced magnetic spacing and improved data recording performance.

Exchange enhanced cap manufactured with argon and oxygen implantation

A perpendicular magnetic recording media comprises a substrate, a first magnetic oxide layer, a first exchange control layer, a second magnetic oxide layer, a second exchange control layer, and a magnetic cap layer positioned above the substrate, in this order. The first magnetic oxide layer may have an anisotropy energy (Ku) between 6&#xd7;10and 8&#xd7;10erg/cm, and a magnetization (Ms) between 600 and 800 emu/cm. The second magnetic oxide layer may have a Ku between 5&#xd7;10and 8&#xd7;10erg/cm, and an Ms between 550 and 750 emu/cm. The first exchange control layer may have an Ms between 0 and 100 emu/cm. The second exchange control layer may have an Ms between 0 and 40 emu/cm.

High performance perpendicular magnetic granular media consisting of multiple exchange control layers

A perpendicular recording medium having a perpendicular magnetic recording layer and a magnetically soft underlayer structure disposed beneath the recording layer. The soft underlayer structure includes at least first and second soft magnetic layers having different magnetic permeabilities to create a magnetic permeability gradient in the soft underlayer structure. One or more of the soft magnetic layers can be antiparallel coupled. The soft underlayer structure of the present invention having a magnetic permeability gradient advantageously leads to reduced adjacent track erasure (ATE) while maintaining good overwrite (OW) properties.

Magnetic recording medium for perpendicular magnetic recording

Perpendicular magnetic recording disks and methods of fabricating perpendicular magnetic recording disks are described. The perpendicular magnetic recording disk includes a soft magnetic underlayer (SUL) structure, an interlayer, and a perpendicular magnetic recording layer. The SUL structure has an increased permeability from an inner radius of the disk to an outer radius of the disk. As a result, the magnetic write width (MWW) on the tracks of the disk is substantially uniform throughout the disk.

Perpendicular magnetic recording disk having a permeability gradient

A perpendicular recording medium having a perpendicular magnetic recording layer and a magnetically soft underlayer structure disposed beneath the recording layer. The soft underlayer structure includes at least first and second soft magnetic layers having different magnetic permeabilities to create a magnetic permeability gradient in the soft underlayer structure. One or more of the soft magnetic layers can be anti-parallel coupled. The soft underlayer structure of the present invention having a magnetic permeability gradient advantageously leads to reduced adjacent track erasure (ATE) while maintaining good overwrite (OW) properties.

Soft magnetic film fabricated with preferred uniaxial anisotropy for perpendicular recording. One type of cathode design has a field direction that is parallel to the direction of the Hex of the second SUL with a magnetically-pinned first SUL. In addition, SUL structures having low AP exchange energy also are disclosed. The SUL structure combines the cathode field direction of the SULwith the pinned SUL. The SULis magnetically pinned to the pinning layer and the pinning direction is parallel to the direction of the cathode field applied during deposition of the SUL. High Hc ferro-magnetic materials may be deposited onto a heated substrate that is magnetized along the radial direction by the cathode field. The pinning field may be higher than the cathode field, indicating that the cathode field during deposition of the SULcannot disturb the magnetic state of the SULpinned to pinning layer.

Methods and apparatus to fabricate soft magnetic film with preferred uniaxial anisotropy for perpendicular recording

A method is described for improving recording performance of a perpendicular media. The method includes controlling the anisotropy levels in different sublayers of the magnetic recording layers of the perpendicular media. Further, the different sublayers thicknesses can be altered to match the media to a particular head.

Magnetic recording capping layer with multiple layers for controlling anisotropy for perpendicular recording media

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

Perpendicular recording media with sublayers of oxide dopant magnetic materials

Perpendicular magnetic recording media having a magnetic capping layer that is exchange coupled to an underlying perpendicular magnetic recording layer. The magnetic coupling layer is a granular layer having a high saturation magnetization (M). The perpendicular magnetic recording layer can include magnetic grains separated by an oxide grain boundary phase.

Media for high density perpendicular magnetic recording

Perpendicular magnetic recording media and methods of fabricating perpendicular magnetic recording media are described. The perpendicular magnetic recording medium of one embodiment includes a soft magnetic underlayer (SUL), an interlayer, and a perpendicular magnetic recording layer. The interlayer comprises a layer formed from a first material (e.g., NiWCr) having a face-centered-cubic (FCC) structure, a layer formed from a second material (e.g., Cr) having a body-centered-cubic (BCC) structure, and a layer formed from a third material (e.g., Ru) having a hexagonal-close-packed (HCP) structure.

Perpendicular magnetic recording medium having a multi-layer interlayer that includes BCC material

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&#xd7;10erg/cm; 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.

Method to improve remanence-squareness-thickness-product and coercivity profiles in magnetic media

An improved soft underlayer structure for perpendicular magnetic recording. The structure includes at least two soft underlayers separated by a non-magnetic spacer layer. The soft underlayer structure incorporates exchange coupling induced anisotropy for improved perpendicular magnetic recording properties, including an improved signal-to-noise ratio (SNR) and reduced adjacent track erasure.

Soft magnetic underlayer with exchange coupling induced anisotropy for perpendicular magnetic recording media

Magnetic recording media having improved magnetic properties such as an improved signal-to-noise ratio. The recording media includes a magnetic recording layer and an underlayer disposed beneath the magnetic recording layer. The underlayer is a Cr-based alloy such as CrMo that includes an additive selected from boron (B), silicon (Si) and boron nitride (BN). The additive preferentially segregates to the grain boundaries in the underlayer to reduce the grain size and grain size distribution in the underlayer.

High density longitudinal recording media

A perpendicular magnetic recording medium having good perpendicular magnetic anisotropy. The magnetic recording medium includes a tantalum (Ta) seedlayer and a ruthenium (Ru) underlayer. The magnetic recording layer can be fabricated from cobalt (Co) alloys. With the Ta seedlayer, the perpendicular anisotropy and c-axis orientation of the magnetic recording layer are greatly enhanced. Unity squareness is achievable as is a negative nucleation field. The magnetic recording medium can be formed by sputtering the various layers onto a substrate. Thus, a perpendicular magnetic recording medium suitable for mass production is provided.

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San Jose, CA, United States of America

Gunn Choe