Containing Elemental Nitrogen In Carbon Overcoat Patents (Class 428/835.4)
  • Patent number: 8980448
    Abstract: A magnetic recording medium includes a substrate; a metal film layer disposed on the substrate; a protective film disposed on the metal film layer; and a lubricant film disposed on a surface of the protective film. The protective film is composed of amorphous carbon containing fluorine and nitrogen in a surface region, and a region deeper than 0.5 nm deep from the surface of the protective film is substantially free from the fluorine and nitrogen. The fluorine and nitrogen may be each added in an amount of 5 to 20 at. %. The present invention simultaneously accomplishes a reduction in film thickness, an improvement in durability and corrosion resistance, and an improvement of the bonding strength of the surface of the protective film to the lubricating film.
    Type: Grant
    Filed: February 23, 2011
    Date of Patent: March 17, 2015
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Naruhisa Nagata, Ryoji Kobayashi, Yoshihisa Suzuki
  • Patent number: 8551627
    Abstract: This invention provides a magnetic disk which can satisfactorily suppress the elution of internal components from an end face of a magnetic disk, and corrosion damage. The magnetic disk comprises a disk substrate, and a thin film including a magnetic layer, a carbon-based protective layer, and a lubricating layer provided in that order on the disk substrate. The main surface and the end face of the magnetic disk are covered with the carbonaceous protective layer. The carbon-based protective layer contains nitrogen at a part adjacent to the lubricating layer. The content of nitrogen atoms relative to the content of carbon atoms in the protective layer formed on the end face is equal to or more than the content of nitrogen atoms relative to the content of carbon atoms in the protective layer formed on the main surface.
    Type: Grant
    Filed: September 24, 2008
    Date of Patent: October 8, 2013
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventors: Akira Shimada, Ito Nakamura
  • Patent number: 7501192
    Abstract: A first protection layer is overlaid on the surface of a recording layer in a recording medium. A second protection layer is overlaid on the surface of the recording layer at a position adjacent the first protection layer. The second protection layer has a composition different from that of the first protection layer. The first and second protection layers have different compositions, so that the overall protection layer is allowed to have an unequal property. The second protection layer may have a hardness higher than that of the first protection layer. A higher hardness of the second protection layer serves to avoid damages on the surface of the recording medium rather than the first protection layer. The recording medium can reliably be protected from collision or contact of an object.
    Type: Grant
    Filed: August 17, 2004
    Date of Patent: March 10, 2009
    Assignee: Fujitsu Limited
    Inventors: Takayuki Musashi, Yoshiharu Kasamatsu
  • Patent number: 7391592
    Abstract: A magnetic recording medium having a diamond-like carbon (DLC) film added therein a Group IV element of the periodic table such as silicon, particularly in the vicinity of the boundary between the magnetic material and the formed DLC film. Since a DLC having low friction coefficient can be formed, the centerline average roughness can be reduced to 30 nm or even less. Accordingly, a magnetic recording medium improved in magnetic properties and in lubricity can be obtained.
    Type: Grant
    Filed: July 26, 2006
    Date of Patent: June 24, 2008
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventor: Shigenori Hayashi
  • Patent number: 7083873
    Abstract: A magnetic recording medium having a diamond-like carbon (DLC) film added therein a Group IV element of the periodic table such as silicon, particularly in the vicinity of the boundary between the magnetic material and the formed DLC film. Since a DLC having low friction coefficient can be formed, the centerline average roughness can be reduced to 30 nm or even less. Accordingly, a magnetic recording medium improved in magnetic properties and in lubricity can be obtained.
    Type: Grant
    Filed: November 17, 2003
    Date of Patent: August 1, 2006
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventor: Shigenori Hayashi
  • Patent number: 7018729
    Abstract: The fabrication of the overcoat layer starts with a low energy ion beam to avoid magnetic layer implantation problems, followed by higher deposition energies where the higher energy atoms are implanted into the previously formed lower energy overcoat layer, rather than the magnetic layer. The energy gradient ion beam deposition process therefore results in a thin overcoat layer that is denser than a comparable layer formed by low energy magnetron sputtering, and which overcoat layer provides good mechanical and corrosion protection to the magnetic layer, without degrading the magnetic properties of the magnetic layer.
    Type: Grant
    Filed: June 30, 2003
    Date of Patent: March 28, 2006
    Assignee: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventors: Daryl J. Pocker, Jan-Ulrich Thiele, Richard L. White, Bing K. Yen
  • Patent number: 6974642
    Abstract: A carbonaceous protective layer particularly suitable for use in magnetic recording media. The carbonaceous protective layer is formed by a Filtered Cathodic Arc process, and contains nitrogen distributed therein. A process for the production of a carbonaceous protective layer as well as a magnetic recording medium and a magnetic disk apparatus are also disclosed.
    Type: Grant
    Filed: May 4, 2001
    Date of Patent: December 13, 2005
    Assignee: Fujitsu Limited
    Inventors: Hiroyuki Hyodo, Takayuki Yamamoto