Patents by Inventor Roger Alan Ristau

Roger Alan Ristau 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: 6645614
    Abstract: A high areal recording density magnetic recording medium having improved thermal stability comprises: a non-magnetic substrate having at least one surface; and a layer stack overlying the at least one surface, comprised of at least one layer pair composed of first and second superposed ferromagnetic layers spaced-apart by a magnetic coupling structure comprising a thin non-magnetic spacer layer and at least one thin ferromagnetic interface layer at at least one interface between the non-magnetic spacer layer and the superposed ferromagnetic layers; wherein the thickness of the ferromagnetic interface layer is selected to provide enhancement of the magnetic coupling between the pair of ferromagnetic layers, thereby increasing the thermal stability of the magnetic recording medium.
    Type: Grant
    Filed: July 11, 2001
    Date of Patent: November 11, 2003
    Assignee: Seagate Technology LLC
    Inventors: Erol Girt, Roger Alan Ristau
  • Patent number: 6589676
    Abstract: Corrosion resistant magnetic thin film media are fabricated using a CoCr magnetic layer having a stabilized protective chromium oxide film thereon. Stabilization of the protective chromium oxide film is achieved by incorporating a stabilizing element, such as Mo, V, Mn, Nb, Ni or Si, in the magnetic layer, thereby enabling elimination of the protective overcoat, e.g., C-containing protective overcoat, or forming the protective overcoat at a significantly low thickness of less than about 20 Å, e.g., up to about 1 Å. Embodiments include forming a magnetic layer comprising Co and Cr on an underlayer, and then forming a thin magnetic layer containing Co and Cr with the chromium oxide stabilizing element thereon. Embodiments further include introducing the chromium oxide stabilizing element by diffusion or ion implantation into a sputter deposited Co—Cr magnetic alloy layer.
    Type: Grant
    Filed: July 12, 2001
    Date of Patent: July 8, 2003
    Assignee: Seagate Technology LLC
    Inventors: Jing Gui, Raj Thangaraj, Roger Alan Ristau, Samuel Dacke Harkness, IV, Gary Clark Rauch