Patents by Inventor Sudhir S. Malhotra

Sudhir S. Malhotra 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: 8956741
    Abstract: Media may be produced with narrow c-axis dispersion while having small grain size and high grain density. A dual seed layer design and a substrate bias voltage may be applied during deposition of the seed layer are used in the media. In some embodiments, the first seed layer is an amorphous material because of a high content of elements with large atomic sizes. Application of the substrate bias during deposition of the second seed layer may reduce the grain size and may narrow c-axis dispersion.
    Type: Grant
    Filed: June 30, 2011
    Date of Patent: February 17, 2015
    Assignee: WD Media, LLC
    Inventors: Tuqiang Li, Donald C. Stafford, Sudhir S. Malhotra, Tsutomu T. Yamashita
  • Patent number: 8597723
    Abstract: A perpendicular magnetic recording disk having a single domain exchange-coupled laminated soft magnetic underlayer (SUL) is disclosed. The SUL is a combination synthetic anti-parallel coupled SUL structure, which has the product (Mst) of saturation magnetization and film thickness of the middle ferromagnetic layer less than the sum of the Mst of the bottom and top ferromagnetic layers. Subjected to a post radial field reset process, this SUL provides single domain state. Moreover, both robustness of stray fields and low permeability are obtained while keeping excellent corrosion resistance and cost effective manufacturability.
    Type: Grant
    Filed: January 10, 2011
    Date of Patent: December 3, 2013
    Assignee: WD Media, LLC
    Inventors: Hong-Sik Jung, Emur M. Velu, Sudhir S. Malhotra, Jackie Tsoi Jung, Gerardo A. Bertero
  • Patent number: 8488276
    Abstract: A perpendicular magnetic recording (PMR) media including a non-magnetic or superparamagnetic grain isolation magnetic anisotropy layer (GIMAL) to provide a template for initially well-isolated small grain microstructure as well as improvement of Ku in core grains of a magnetic recording layer. The GIMAL composition may be adjusted to have lattice parameters similar to a bottom magnetic recording layer and to provide a buffer for reducing interface strains caused by lattice mismatch between the bottom magnetic recording layer and an underlying layer.
    Type: Grant
    Filed: September 30, 2008
    Date of Patent: July 16, 2013
    Assignee: WD Media, LLC
    Inventors: Hong-Sik Jung, Donald Stafford, B. Ramamurthy Acharya, Sudhir S. Malhotra, Gerardo A. Bertero
  • Patent number: 8394243
    Abstract: Method of incorporating atomic oxygen into a magnetic recording layer by sputtering a target containing an oxide of cobalt. The oxide of cobalt may be sputtered to provide a readily dissociable source of oxygen which may increase the concentration of free cobalt atoms (Co) in the magnetic recording layer and also increase oxide content in the magnetic recording layer.
    Type: Grant
    Filed: September 30, 2008
    Date of Patent: March 12, 2013
    Assignee: WD Media, Inc.
    Inventors: Hong-Sik Jung, Donald Stafford, B. Ramamurthy Acharya, Sudhir S. Malhotra, Gerardo A. Bertero
  • Patent number: 7179549
    Abstract: A magnetic recording medium constructed in accordance with the invention comprises a substrate, first, second and third underlayers formed over the substrate, and a magnetic data recording layer formed over the underlayers. The underlayers typically have a bcc crystal structure, and comprise Cr or Cr alloys. The magnetic data recording layer has a hcp crystal structure and comprises a Co alloy. The second underlayer typically comprises a material such as B, which tends to reduce the crystal size of the second underlayer and the layers deposited thereon, and also to increase crystal spacing.
    Type: Grant
    Filed: January 21, 2004
    Date of Patent: February 20, 2007
    Assignee: Komag, Inc.
    Inventors: Sudhir S. Malhotra, Gerardo Bertero, Ching Tsoi, Donald Stafford
  • Patent number: 6303217
    Abstract: A magnetic recording medium having a dual underlayer structure is described. The underlayer structure is composed of a first underlayer of chromium and a second underlayer of a chromium alloy.
    Type: Grant
    Filed: October 2, 1998
    Date of Patent: October 16, 2001
    Assignee: HMT Technology, Corporation
    Inventors: Sudhir S. Malhotra, Brij Bihari Lal, Michael A. Russak
  • Patent number: 6146737
    Abstract: A magnetic recording medium having a barrier layer deposited directly on the magnetic recording layer is described. The barrier layer is deposited by sputter deposition under a nitrogen-containing sputtering atmosphere to form a nitrogen-containing chromium or chromium alloy barrier layer. The barrier layer is effective to inhibit migration of cobalt from the underlying magnetic recording layer, reducing corrosion of the medium and improving magnetic recording performance.
    Type: Grant
    Filed: September 18, 1998
    Date of Patent: November 14, 2000
    Assignee: HMT Technology Corporation
    Inventors: Sudhir S. Malhotra, Brij Bihari Lal, James L. Chao, Michael A. Russak
  • Patent number: 6007924
    Abstract: An improvement in a magnetic recording medium having an underlayer and first and second magnetic recording layers is described. The improvement, effective to reduce media noise, includes deposition of an interlayer between the first and second magnetic recording layers. The interlayer is deposited to a thickness of between 5-50 .ANG. and is composed of an CoCr-based alloy having a defined saturation magnetization.
    Type: Grant
    Filed: July 2, 1997
    Date of Patent: December 28, 1999
    Assignee: HMT Technology Corporation
    Inventors: Brij Bihari Lal, Sudhir S. Malhotra, Michael A. Russak
  • Patent number: 5922442
    Abstract: An improvement in a magnetic recording medium having an underlayer and a magnetic layer is described. The improvement, effective to increase the coercivity of the medium, includes deposition of an interlayer between the underlayer and the magnetic recording layer. The interlayer is deposited to a thickness of between 10-60 .ANG. and is composed of an CoCr-based alloy having a defined saturation magnetization.
    Type: Grant
    Filed: March 28, 1997
    Date of Patent: July 13, 1999
    Assignee: HMT Technology Corporation
    Inventors: Brij Bihari Lal, Sudhir S. Malhotra, Michael A. Russak
  • Patent number: 5849386
    Abstract: An improvement in a magnetic recording medium having an underlayer and a magnetic recording layer is described. The improvement, effective to reduce media anisotropy, includes deposition of a prelayer on the substrate, prior to deposition of the underlayer. The prelayer is deposited to a thickness of between 10-60 .ANG. and is composed of an CoCr-based alloy having a defined saturation magnetization.
    Type: Grant
    Filed: August 7, 1997
    Date of Patent: December 15, 1998
    Assignee: HMT Technology Corporation
    Inventors: Brij Bihari Lal, Sudhir S. Malhotra, Michael A. Russak