Neil E Smith

US Patent:

6473279, Oct 29, 2002

Filed:

Jan 4, 2001

Appl. No.:

09/754908

Inventors:

Neil Smith - San Jose CA
Bo Yang - Beijing, CN

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G11B 539

US Classification:

36032412, 360113

Abstract:

An improved MR sensor has a ferromagnetic free layer whose magnetization is stabilized by an in-stack three layers combination, which including an auxiliary ferromagnetic layer proximate the ferromagnetic free layer, a non-magnetic spacer layer disposed between the ferromagnetic free layer and the auxiliary ferromagnetic layer, and a pinning layer adjacent to the auxiliary ferromagnetic layer. The pinning layer is directly exchange-coupled to the auxiliary ferromagnetic layer such that the magnetization of the auxiliary ferromagnetic layer is pinned. The non-magnetic spacer layer is made of a material, such as Ru, which induces an anti-ferromagnetic exchange coupling between the ferromagnetic free layer and the auxiliary ferromagnetic layer. The magnetization of the ferromagnetic free layer is stabilized in a single-domain state by the combination of the anti-ferromagnetic exchange-coupling and magnetostatic coupling between the ferromagnetic free layer and the auxiliary ferromagnetic layer.

US Patent:

6693769, Feb 17, 2004

Filed:

Jun 18, 2001

Appl. No.:

09/884608

Inventors:

Yimin Hsu - Sunnyvale CA
Hugo Alberto Emilio Santini - San Jose CA
Neil Smith - San Jose CA
Mason Lamar Williams - San Jose CA

Assignee:

Hitachi Global Storage Technologies Netherlands B.V. - Amsterdam

International Classification:

G11B 5147

US Classification:

360126, 360317

Abstract:

A magnetic head assembly includes first and second pole pieces and first and second coil layers wherein the second pole piece has a ferromagnetic pole tip which forms a portion of an air bearing surface and defines a track width of a write head. A write gap layer is located between the first pole piece and the pole tip. A dielectric first insulation layer interfaces first and second side surfaces of the pole tip and is located between the first and second coil layers. The second pole piece has a ferromagnetic second pole piece structure which is magnetically connected to each of the pole tip and the first pole piece and extends across the second coil layer. In a first embodiment the second pole piece structure is a single layer and in a second embodiment the second pole piece structure has front and back components with a flat laminated second pole piece yoke layer located therebetween.

US Patent:

6778364, Aug 17, 2004

Filed:

Aug 28, 2002

Appl. No.:

10/230903

Inventors:

Elizabeth A. Dobisz - San Jose CA
James L. Nix - Gilroy CA
Neil Smith - San Jose CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G11B 539

US Classification:

36032412

Abstract:

A current-in-the-plane (CIP) giant magnetoresistive (GMR) spin valve sensor has its free layer magnetization stabilized by longitudinal biasing through the use of free layer end-region antiferromagnetic exchange coupling. An antiparallel coupling (APC) layer, such as Ru, is formed on the free layer and a ferromagnetic bias layer is formed on the APC layer. The bias layer is a continuous layer that extends across the entire width of the free layer. The central region of the bias layer is formed of nonmagnetic oxides of one or more of the elements making up the bias layer, with the bias layer end regions remaining ferromagnetic. The oxidized central region of the bias layer defines the central active trackwidth region of the underlying free layer. The ferromagnetic end regions of the bias layer are antiferromagnetically coupled across the APC layer to the corresponding underlying free layer end regions to provide the longitudinal biasing.

US Patent:

6835475, Dec 28, 2004

Filed:

Jul 26, 2001

Appl. No.:

09/916390

Inventors:

Matthew J. Carey - San Jose CA
Yoshihiro Ikeda - San Jose CA
Neil Smith - San Jose CA
Kentaro Takano - San Jose CA

Assignee:

Hitachi Global Storage Technologies Netherlands B.V. - Amsterdam

International Classification:

G11B 566

US Classification:

428694TS, 428694 TM, 428212, 428900

Abstract:

A dual-layer type perpendicular magnetic recording disk for use in a perpendicular magnetic recording system that uses a single pole recording head has a laminated underlayer that has at least two ferromagnetic films exchange-coupled across an antiferromagnetic coupling layer. The magnetic moments of the ferromagnetic layers in the laminated underlayer are oriented antiparallel. The laminated underlayer provides a soft magnetically permeable flux return path without undesirable domain walls and associated media noise, with controllable permeability and minimization of saturation of the upper ferromagnetic layers. In one embodiment the moments of the ferromagnetic layers in the underlayer are oriented generally radially on the disk. In another embodiment the moments are oriented generally circumferentially in the track direction on the disk, so that the beneficial effect of the soft magnetic underlayer occurs primarily only during the writing process.

US Patent:

6952326, Oct 4, 2005

Filed:

Jun 30, 2003

Appl. No.:

10/611627

Inventors:

Yimin Hsu - Sunnyvale CA, US
Hugo Alberto Emilio Santini - San Jose CA, US
Neil Smith - San Jose CA, US
Mason Lamar Williams - San Jose CA, US

Assignee:

Hitachi Global Storage Technologies Netherlands B.V. - Amsterdam

International Classification:

G11B005/127

US Classification:

360126

Abstract:

A magnetic head assembly includes first and second pole pieces and first and second coil layers wherein the second pole piece has a ferromagnetic pole tip which forms a portion of an air bearing surface and defines a track width of a write head. A write gap layer is located between the first pole piece and the pole tip. A dielectric first insulation layer interfaces first and second side surfaces of the pole tip and is located between the first and second coil layers. The second pole piece has a ferromagnetic second pole piece structure which is magnetically connected to each of the pole tip and the first pole piece and extends across the second coil layer. In a first embodiment the second pole piece structure is a single layer and in a second embodiment the second pole piece structure has front and back components with a flat laminated second pole piece yoke layer located therebetween.

US Patent:

6972935, Dec 6, 2005

Filed:

Aug 13, 2004

Appl. No.:

10/917982

Inventors:

Elizabeth A. Dobisz - San Jose CA, US
James L. Nix - Gilroy CA, US
Neil Smith - San Jose CA, US

Assignee:

Hitachi Global Storage Technologies Netherlands B.V. - Amsterdam

International Classification:

G11B005/39

US Classification:

36032412

Abstract:

A current-in-the-plane (CIP) giant magnetoresistive (GMR) spin valve sensor has its free layer magnetization stabilized by longitudinal biasing through the use of free layer end-region antiferromagnetic exchange coupling. An antiparallel coupling (APC) layer, such as Ru, is formed on the free layer and a ferromagnetic bias layer is formed on the APC layer. The bias layer is a continuous layer that extends across the entire width of the free layer. The central region of the bias layer is formed of nonmagnetic oxides of one or more of the elements making up the bias layer, with the bias layer end regions remaining ferromagnetic. The oxidized central region of the bias layer defines the central active track-width region of the underlying free layer. The ferromagnetic end regions of the bias layer are antiferromagnetically coupled across the APC layer to the corresponding underlying free layer end regions to provide the longitudinal biasing.

US Patent:

7009812, Mar 7, 2006

Filed:

Sep 29, 2003

Appl. No.:

10/675046

Inventors:

Yimin Hsu - Sunnyvale CA, US
Quang Le - San Jose CA, US
Hin Pong Edward Lee - San Jose CA, US
James Lamar Nix - Gilroy CA, US
Aron Pentek - San Jose CA, US
Kurt Rubin - San Jose CA, US
Neil Smith - San Jose CA, US
Nian Xiang Sun - Sunnyvale CA, US
Walter Eugene Weresin - San Jose CA, US
Mason Lamar Williams - San Jose CA, US

Assignee:

Hitachi Global Storage Technologies Netherlands B.V. - Amsterdam

International Classification:

G11B 5/147

US Classification:

360126

Abstract:

The invention is a magnetic transducer with separated read and write heads for perpendicular recording. The write head has a trailing shield that extends from the return pole piece toward the main pole piece to form the write gap at the air-bearing surface. One embodiment of the trailing shield is a two part structure with a pedestal and a much smaller tip that confronts the main pole piece at the gap. In one embodiment a sink of non-magnetic, electrically conductive material is disposed in the separation gap between the read head and the flux bearing pole piece. The sink is preferably made of copper and does not extend to the ABS.

US Patent:

7054085, May 30, 2006

Filed:

Jun 30, 2003

Appl. No.:

10/611590

Inventors:

Tsann Lin - Saratoga CA, US
Daniele Mauri - San Jose CA, US
Neil Smith - San Jose CA, US

Assignee:

Hitachi Global Storage Technologies Netherlands B.V. - Amsterdam

International Classification:

G11B 5/09

US Classification:

360 46, 360 67, 3602344, 3602355, 360313, 3603242

Abstract:

A read head for use with an interconnect transmission line having a characteristic impedance of Zincludes a tunnel valve device and a shunt resistor RS that is connected in parallel across the tunnel valve device. The tunnel valve device has a device resistance Rcorresponding to a predetermined resistance-area (RA) product. The value of the shunt resistance is based on the parallel combination of Rand Rsubstantially equaling the characteristic impedance Zof the interconnect transmission line. The predetermined resistance-area (RA) product is about equal to at least about 10 Ohms-μm. Alternatively, the predetermined resistance-area (RA) product is about equal to a “corner” value of RAfor the tunnel valve device.