Patents Assigned to Hitachi Global Storage Techologies Netherlands, B.V.
  • Patent number: 7662492
    Abstract: 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.
    Type: Grant
    Filed: April 17, 2007
    Date of Patent: February 16, 2010
    Assignee: Hitachi Global Storage Techologies Netherlands, B.V.
    Inventors: Gunn Choe, Kai Tang
  • Publication number: 20080254324
    Abstract: A perpendicular magnetic recording medium has an “exchange-spring” type magnetic recording layer (RL) with an improved coupling layer (CL). The RL includes the first or lower ferromagnetic layer MAG1, sometimes called the “media” layer, the second or upper ferromagnetic layer MAG2, sometimes called the “exchange-spring” layer, and the intermediate CL that provides ferromagnetic exchange coupling between MAG1 and MAG2. The CL is formed of NiCr or RuCr based alloys, or CoCr or CoCrB alloys with high Cr and/or B content (Cr plus B>about 25 atomic percent), or RuCoCr alloys with low Co content (<about 65 atomic percent). For each CL composition there is a CL thickness range that provides the optimal interlayer exchange coupling between MAG1 and MAG2. The selected CL materials provide an exchange-type perpendicular magnetic recording medium with good magnetic performance, while the relatively high amount of Cr of the CL improves the corrosion resistance of the medium.
    Type: Application
    Filed: April 16, 2007
    Publication date: October 16, 2008
    Applicant: HITACHI GLOBAL STORAGE TECHOLOGIES NETHERLANDS B.V.
    Inventors: Andreas Klaus Berger, Xiaoping Bian, Mary Frances Minardi, Kentaro Takano, Kai Tang
  • Publication number: 20070276993
    Abstract: Embodiments in accordance with the present invention increase a hit ratio of cache by deciding an access area for reading ahead using a latency time based on the feature of an access pattern. A disk unit comprises preceding data reading ahead means for reading the preceding data of read request data, succeeding data reading ahead means for reading ahead the succeeding data of read request data, and means for extracting the feature of the access pattern by monitoring the command.
    Type: Application
    Filed: May 9, 2007
    Publication date: November 29, 2007
    Applicant: Hitachi Global Storage Techologies Netherlands B.V.
    Inventor: Yukie Hiratsuka
  • Publication number: 20070030597
    Abstract: When the flying height of a magnetic head slider lowers, there arises the problem that the magnetic head slider assumes a forwardly falling attitude and a front edge portion of a leading end of the magnetic head slider comes into contact with a magnetic disk surface, causing damage to the disk surface. To address the problem, one aspect of the invention is directed to a magnetic head slider which includes an air bearing surface, a leading end and a trailing end. Three flying pads are formed on the air bearing surface and a step bearing surface is formed around the first and second flying pads near the leading end and a negative pressure groove for producing a negative pressure is formed in such a manner that the leading side is surrounded by the step bearing surface. The third flying pad is formed near the trailing end and is provided with a magnetic head. A step bearing is formed on the leading side of the third flying pad.
    Type: Application
    Filed: August 8, 2006
    Publication date: February 8, 2007
    Applicant: Hitachi Global Storage Techologies Netherlands B. V.
    Inventors: Kouichi Watanabe, Sunao Yonekawa