Patents by Inventor Bollapragada Varaprasad

Bollapragada Varaprasad 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).

  • Publication number: 20160225393
    Abstract: A perpendicular magnetic recording medium which has a magnetic layer comprising a material having FePt alloy as a main component on a substrate, characterized in that the magnetic layer is an FePtAg—C or FePt—C granular thin film obtained by laminating a unit in multiple stages, the unit being a laminate film obtained by forming, on an FePtAg—C layer or an FePt—C layer, at least one layer of (A) FePtAg layer or FePt layer or (B) FePtAg—C layer or FePt—C layer which has carbon concentration different from the above FePtAg—C layer or FePt—C layer. Consequently, a perpendicular magnetic recording medium using an FePtAg—C or FePt—C granular thin film which satisfies both the high order and columnar structure required for achieving recording density of more than 1 Tbit/in2, for example, can be provided.
    Type: Application
    Filed: August 25, 2014
    Publication date: August 4, 2016
    Applicant: NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Bollapragada VARAPRASAD, Yukiko TAKAHASHI, Kazuhiro HONO
  • Patent number: 8993134
    Abstract: A perpendicular magnetic recording medium, comprising: a substrate; a buffer layer deposited in a first orientation on top of the substrate; an underlayer deposited in a second orientation on top of the buffer layer, the underlayer comprising an electrically conductive oxide; and a magnetic recording layer deposited on top of the underlayer and having an axis of magnetic anisotropy substantially perpendicular to the surface thereof.
    Type: Grant
    Filed: June 29, 2012
    Date of Patent: March 31, 2015
    Assignee: Western Digital Technologies, Inc.
    Inventors: Bollapragada Varaprasad, Yukiko Takahashi, Kazuhiro Hono, Antony Ajan, Hua Yuan, Alexander S. Chernyshov