Patents by Inventor Hardayal Singh Gill

Hardayal Singh Gill has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7280326
    Abstract: A current perpendicular to plane (CPP) GMR sensor having first and second outer pinned layers and a trilayer free layer therebetween. The free layer includes first and second outer magnetic layers, and a partially oxidized magnetic layer disposed there between. The middle partially oxidized layer is antiparallel coupled with the outer magnetic layers of the free layer by first and second coupling layers which prevent oxygen migration from the central layer into the outer magnetic layers of the free layer. The partial oxidation of the middle layer provides a limited amount of electrical resistance at a desired location within the free layer to increase GMR.
    Type: Grant
    Filed: July 30, 2004
    Date of Patent: October 9, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Singh Gill
  • Patent number: 7280324
    Abstract: A magnetoresistive sensor having improved free layer biasing and track width control.
    Type: Grant
    Filed: February 17, 2004
    Date of Patent: October 9, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Singh Gill
  • Patent number: 7277260
    Abstract: A magnetic head that includes a spin valve sensor of the present invention which may be a CIP or CPP device. The sensor includes a free magnetic layer that is comprised of CoFeCu. In certain embodiments the free magnetic layer may also include a sublayer of NiFe. The CoFeCu free magnetic layer preferably includes Fe in a range of 5-20 at. % and Cu in a range of 1-10 at. %. The sensor may also include a cap layer of the present invention that is comprised of ZnOx/TaOx. The CoFeCu free magnetic layer of the present invention provides improved sensor performance characteristics of reduced coercivity and generally similar GMR as compared to the prior art. Where the ZnOx/TaOx cap layer is utilized, increased GMR is obtained. Thus a magnetic head of the present invention that includes both a CoFeCu free magnetic layer and a ZnOx/TaOx cap layer demonstrates reduced coercivity and increased GMR.
    Type: Grant
    Filed: September 21, 2004
    Date of Patent: October 2, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventors: Hardayal Singh Gill, Alexander M. Zeltser
  • Publication number: 20070217089
    Abstract: One embodiment of the present invention is directed to a read head for a data storage device including a differential sensor for reading data from a data storage medium. The differential sensor includes a first and a second free layer. The magnetization of the free layers is anti-parallel. The read head also includes a first stabilization material disposed adjacent to the differential sensor. The first stabilization material includes a first hard magnet and a second hard magnet. The magnetization of the hard magnets is anti-parallel to each other. The read head also includes a second stabilization material disposed adjacent to the differential sensor. The second stabilization material includes a first hard magnet and a second hard magnet, wherein the magnetization of the hard magnets is anti-parallel to each other. The anti-parallel coupling of the first stabilization material and the second stabilization material enhances the anti-parallel magnetization of the free layers.
    Type: Application
    Filed: March 17, 2006
    Publication date: September 20, 2007
    Inventor: Hardayal Singh Gill
  • Patent number: 7268980
    Abstract: A magnetic head has a read sensor including a free layer, a spacer layer and a number of self-pinned layers. These self-pinned layers include interleaved layers of ferromagnetic material and non-magnetic metal. The self-pinned layers are pinned through magnetostrictive anisotropy, and preferably have a net magnetic moment which is approximately zero.
    Type: Grant
    Filed: February 11, 2004
    Date of Patent: September 11, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventor: Hardayal Singh Gill
  • Patent number: 7268982
    Abstract: A current perpendicular to plane (CPP) giant magnetoresistive (GMR) sensor having an antiparallel coupled (AP coupled) pinned layer structure wherein the pinning layer have a greatly reduced negative contribution to dR. The pinned layer structure includes a first a first set of magnetic layers such as CoFe and a second set of magnetic layer comprising CoFeV that are antiparallel coupled with the first set of magnetic layers. The magnetic layers of the pinned layer structure alternate between a one of the first set of magnetic layers (eg. CoFe) and one of the second set of magnetic layers (CoFeV). The magnetic layers of the first set contribute to the GMR of the sensor and provide a positive magnetostriction that assists with the pinning of the pinned layer structure. The magnetic layers of the second set contribute pinning, but do not contribute to GMR.
    Type: Grant
    Filed: October 21, 2004
    Date of Patent: September 11, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Singh Gill
  • Patent number: 7268979
    Abstract: The present invention overcomes the drawbacks and limitations described above by providing a magnetic head having a free layer, an antiferromagnetic layer spaced apart from the free layer, and an antiparallel (AP) pinned layer structure positioned between the free layer and the antiferromagnetic layer and having a net magnetic moment equal to about zero. The antiferromagnetic layer provides a coercivity that enhances pinning of the AP pinned layer structure.
    Type: Grant
    Filed: July 2, 2003
    Date of Patent: September 11, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Singh Gill
  • Patent number: 7268986
    Abstract: A double tunnel junction TMR magnetoresistive sensor having first and second magnetic free layers separated by a self pinned magnetic layer. The self pinned magnetic layer is separated from the first and second free layers by thin barrier layers. The pinned layer magnetization is pinned without the need for exchange pinning with an adjacent layer of antiferromagnetic layer.
    Type: Grant
    Filed: March 31, 2004
    Date of Patent: September 11, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Singh Gill
  • Patent number: 7265946
    Abstract: A self pinned CPP GMR sensor having an AP1 layer extending beyond the track width of the sensor and a multilayer AP2 layer including layers of CoFe interspersed with thin non-magnetic layers such as Cu.
    Type: Grant
    Filed: April 30, 2003
    Date of Patent: September 4, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Singh Gill
  • Patent number: 7265951
    Abstract: A magnetic head having a sensor with a free layer, the free layer having a magnetic moment. Hard bias layers are positioned towards opposite track edges of the sensor, the bias layers stabilizing the magnetic moment of the free layer. An antiparallel (AP) pinned layer structure is positioned toward each of the hard bias layers, each AP pinned layer structure having at least two pinned layers with magnetic moments that are self-pinned antiparallel to each other. Each AP pinned layer structure stabilizes a magnetic moment of the hard bias layer closest to it. An antiferromagnetic layer is positioned toward each of the AP pinned layer structures, each antiferromagnetic layer stabilizing a magnetic moment of pinned layer closest to it.
    Type: Grant
    Filed: January 3, 2006
    Date of Patent: September 4, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Singh Gill
  • Patent number: 7256972
    Abstract: A current perpendicular to plane (CPP) sensor having an in stack bias layer having a desired negative magnetostriction for efficient biasing of the free layer. The sensor includes a free layer, a pinned layer and a first spacer layer sandwiched between the free layer and the pinned layer. The sensor further includes an in stack bias structure disposed adjacent to the free layer, opposite the first spacer layer. The in stack bias structure includes a layer of CoFe exchange coupled with a layer of antiferomagnetic (AFM) material. A layer of CoX is then exchange coupled to the layer of CoFe. The element X can be selected from the material including B, Si, SiB, Ni, Nb, and Y.
    Type: Grant
    Filed: June 30, 2004
    Date of Patent: August 14, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Singh Gill
  • Patent number: 7248447
    Abstract: A self pinned magnetoresistive sensor having an anitparallel coupled pinned layer structure including a high coercivity (high Hc) layer of TbCo.
    Type: Grant
    Filed: May 5, 2004
    Date of Patent: July 24, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Singh Gill
  • Patent number: 7245463
    Abstract: A Giant Magneto-Resistive (GMR) sensor (900) having Current Perpendicular to Plane (CPP) structure provides an extended first pinned layer (914) as compared to second pinned layer (912) and free layer (910). Increased magnetoresistance changes, increased pinning strength, increased thermal stability, and decreased susceptibility to Electro-Static Discharge (ESD) events is realized by maintaining equivalent current densities through free layer (910) and second pinned layer (912), while decreasing the relative current density through first pinned layer (914).
    Type: Grant
    Filed: July 25, 2003
    Date of Patent: July 17, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Singh Gill
  • Patent number: 7242556
    Abstract: A current perpendicular to plane (CPP) differential giant magnetoresistive (GMR) sensor that is insensitive to stray longitudinal and transverse magnetic fields. The sensor includes an in stack bias layer structure that is used to bias the magnetic moment of first and second free layers disposed at either side thereof. The bias structure includes an antiferromagnetic layer (AFM). An odd number of antiparallel (AP) coupled magnetic layers are formed on a first side of the AFM and an even number of AP coupled magnetic layers on the opposite side of the AFM.
    Type: Grant
    Filed: June 21, 2004
    Date of Patent: July 10, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Singh Gill
  • Patent number: 7237322
    Abstract: A method for making a tunnel valve head with a flux guide. The tunnel valve sensor is created by forming a tunnel valve at a first shield layer. The tunnel valve includes a free layer distal to the first shield layer, a first insulation layer deposited over the first shield layer and around the tunnel valve, a flux guide formed over the first insulation layer and coupling to the tunnel valve at the free layer, a second insulation layer formed over the flux guide and a second shield layer formed over the second insulation layer. The flux guide and the free layer are physically isolated by the first and second insulation layers to prevent current shunts therefrom. The structure achieves physical connection between the flux guide and the free layer and insulates the flux guide from the shields.
    Type: Grant
    Filed: October 29, 2004
    Date of Patent: July 3, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Singh Gill
  • Patent number: 7236336
    Abstract: A method and apparatus for providing a free layer having higher saturation field capability and optimum sensitivity (dr/R) is disclosed. The present invention provides a synthetic free layer that includes a first and second free layer, wherein the second free layer is a cobalt alloy that provides higher saturation and optimum sensitivity.
    Type: Grant
    Filed: April 30, 2004
    Date of Patent: June 26, 2007
    Assignee: Hitachi Global Storage Technologies Inc, Netherlands B.V.
    Inventor: Hardayal Singh Gill
  • Patent number: 7233461
    Abstract: A magnetic head has a read sensor which includes at least one primary pinned layer, a barrier layer, and a free layer. An in-stack biasing structure having net magnetic moment near zero, notated as dM=0, is constructed above the free layer. This in-stack biasing structure acts to stabilize the free layer by exchange coupling.
    Type: Grant
    Filed: January 20, 2004
    Date of Patent: June 19, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventor: Hardayal Singh Gill
  • Patent number: 7230804
    Abstract: A magnetic tunnel transistor (MTT) is formed with a self-pinned emitter layer. The self-pinned emitter layer decreases resistance in by eliminating a thick resistive adjacent anti-ferromagnetic pinning layer. Also, the present invention reduces a series resistance in a base of the magnetic tunnel transistor by removing a pinned layer from the base.
    Type: Grant
    Filed: May 2, 2003
    Date of Patent: June 12, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Singh Gill
  • Patent number: 7221545
    Abstract: A magnetic head having a free layer, an antiparallel (AP) pinned layer structure spaced apart from the free layer, and a high coercivity structure. The high coercivity structure pins a magnetic orientation of the AP pinned layer structure. The high coercivity structure includes a layer of high coercivity material, and an amorphous layer positioned between the high coercivity material and the AP pinned layer structure.
    Type: Grant
    Filed: February 18, 2004
    Date of Patent: May 22, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Singh Gill
  • Patent number: 7218488
    Abstract: A method and apparatus for reducing the thickness of a sensor stack in a current-perpendicular-to-plane (CPP) GMR/tunnel valve (TV) sensor is disclosed. A layer of alpha-Fe2O3 having a high coercivity is formed adjacent the active areas for pinning the bias layer.
    Type: Grant
    Filed: March 29, 2004
    Date of Patent: May 15, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Singh Gill