Patents by Inventor William G. McChesney

William G. McChesney 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: 6723450
    Abstract: A magnetic recording medium for data storage uses a magnetic recording layer having at least two ferromagnetic films with different remanent magnetization-thickness (Mrt) values that are coupled antiparallel across a nonferromagnetic spacer film predominantly by the dipole field (Hd) from the grains of the higher-Mrt ferromagnetic film. The material compositions and thicknesses of the ferromagnetic films and the nonferromagnetic spacer film are selected so that Hd predominates over any antiferromagnetic exchange coupling field (Haf) and is greater than the coercive field of the lower-Mrt ferromagnetic film. As a result, the magnetizations of the two ferromagnetic films are antiparallel in the two remanent magnetic states, and thus the net remanent magnetization-thickness product (Mrt) of the recording layer is the difference in the Mrt values of the two ferromagnetic films.
    Type: Grant
    Filed: March 19, 2002
    Date of Patent: April 20, 2004
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Hoa Van Do, Mary F. Doerner, Eric Edward Fullerton, David Thomas Margulies, William G. McChesney, Manfred Ernst Schabes, Kai Tang
  • Publication number: 20030180577
    Abstract: A magnetic recording medium for data storage uses a magnetic recording layer having at least two ferromagnetic films with different remanent magnetization-thickness (Mrt) values that are coupled antiparallel across a nonferromagnetic spacer film predominantly by the dipole field (Hd) from the grains of the higher-Mrt ferromagnetic film. The material compositions and thicknesses of the ferromagnetic films and the nonferromagnetic spacer film are selected so that Hd predominates over any antiferromagnetic exchange coupling field (Haf) and is greater than the coercive field of the lower-Mrt ferromagnetic film. As a result, the magnetizations of the two ferromagnetic films are antiparallel in the two remanent magnetic states, and thus the net remanent magnetization-thickness product (Mrt) of the recording layer is the difference in the Mrt values of the two ferromagnetic films.
    Type: Application
    Filed: March 19, 2002
    Publication date: September 25, 2003
    Inventors: Hoa Van Do, Mary F. Doerner, Eric Edward Fullerton, David Thomas Margulies, William G. McChesney, Manfred Ernst Schabes, Kai Tang
  • Patent number: 4350116
    Abstract: A holder for liquid phase epitaxial (LPE) growth which eliminates mesas on the surface of the film is described. The holder has two legs to which a ring is connected. The ring has holding means so that it can hold one wafer or two wafers back-to-back. One of the two legs extends vertically below the first ring. In a preferred embodiment a second ring having holding means for a pair of wafers back-to-back is attached to the elongated leg. This holder structure prevents a film from the liquid melt from forming when the holder is withdrawn from the liquid growth solution, thereby eliminating the formation of mesas which occur when the film ruptures.
    Type: Grant
    Filed: December 22, 1980
    Date of Patent: September 21, 1982
    Assignee: International Business Machines Corporation
    Inventors: Johannes Grandia, William G. McChesney, Hugo A. E. Santini, Harold L. Turk