Patents by Inventor Donald M. Kroeger

Donald M. Kroeger 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: 6114287
    Abstract: The present invention provides methods and biaxially textured articles having a deformed epitaxial layer formed therefrom for use with high temperature superconductors, photovoltaic, ferroelectric, or optical devices. A buffer layer is epitaxially deposited onto biaxially-textured substrates and then mechanically deformed. The deformation process minimizes or eliminates grooves, or other irregularities, formed on the buffer layer while maintaining the biaxial texture of the buffer layer. Advantageously, the biaxial texture of the buffer layer is not altered during subsequent heat treatments of the deformed buffer. The present invention provides mechanical densification procedures which can be incorporated into the processing of superconducting films through the powder deposit or precursor approaches without incurring unfavorable high-angle grain boundaries.
    Type: Grant
    Filed: September 30, 1998
    Date of Patent: September 5, 2000
    Assignee: UT-Battelle, LLC
    Inventors: Dominic F. Lee, Donald M. Kroeger, Amit Goyal
  • Patent number: 6106615
    Abstract: Specific alloys, in particular Ni-based alloys, that can be biaxially textured, with a well-developed, single component texture are disclosed. These alloys have a significantly reduced Curie point, which is very desirable from the point of view of superconductivity applications. The biaxially textured alloy substrates also possess greatly enhanced mechanical properties (yield strength, ultimate tensile strength) which are essential for most applications, in particular, superconductors. A method is disclosed for producing complex multicomponent alloys which have the ideal physical properties for specific applications, such as lattice parameter, degree of magnetism and mechanical strength, and which cannot be in textured form. In addition, a method for making ultra thin biaxially textured substrates with complex compositions is disclosed.
    Type: Grant
    Filed: February 16, 1999
    Date of Patent: August 22, 2000
    Inventors: Amit Goyal, Eliot D. Specht, Donald M. Kroeger, Mariappan Paranthaman
  • Patent number: 6077344
    Abstract: A method is disclosed for forming a biaxially textured buffer layer on a biaxially oriented metal substrate by using a sol-gel coating technique followed by pyrolyzing/annealing in a reducing atmosphere. This method is advantageous for providing substrates for depositing electronically active materials thereon.
    Type: Grant
    Filed: September 2, 1997
    Date of Patent: June 20, 2000
    Assignee: Lockheed Martin Energy Research Corporation
    Inventors: Shara S. Shoup, Mariappan Paranthamam, David B. Beach, Donald M. Kroeger, Amit Goyal
  • Patent number: 6055446
    Abstract: A layered oxide superconductor prepared by depositing a superconductor precursor powder on a continuous length of a first substrate ribbon. A continuous length of a second substrate ribbon is overlaid on the first substrate ribbon. Sufficient pressure is applied to form a bound layered superconductor precursor powder between the first substrate ribbon and the second substrate ribbon. The layered superconductor precursor is then heat treated to establish the oxide superconducting phase. The layered oxide superconductor has a smooth interface between the substrate and the oxide superconductor.
    Type: Grant
    Filed: November 26, 1997
    Date of Patent: April 25, 2000
    Assignee: Martin Marietta Energy Systems, Inc.
    Inventors: Donald M. Kroeger, Frederick A. List, III
  • Patent number: 5968877
    Abstract: A superconducting article includes a biaxially-textured Ni substrate, and epitaxial buffer layers of Pd (optional), CeO.sub.2 and YSZ, and a top layer of in-plane aligned, c-axis oriented YBCO having a critical current density (J.sub.c) in the range of at least 100,000 A/cm.sup.2 at 77 K.
    Type: Grant
    Filed: June 26, 1996
    Date of Patent: October 19, 1999
    Assignee: Lockheed Martin Energy Research Corp
    Inventors: John D. Budai, David K. Christen, Amit Goyal, Qing He, Donald M. Kroeger, Dominic F. Lee, Frederick A. List, III, David P. Norton, Mariappan Paranthaman, Brian C. Sales, Eliot D. Specht
  • Patent number: 5964966
    Abstract: Specific alloys, in particular Ni-based alloys, that can be biaxially textured, with a well-developed, single component texture are disclosed. These alloys have a significantly reduced Curie point, which is very desirable from the point of view of superconductivity applications. The biaxially textured alloy substrates also possess greatly enhanced mechanical properties (yield strength, ultimate tensile strength) which are essential for most applications, in particular, superconductors. A method is disclosed for producing complex multicomponent alloys which have the ideal physical properties for specific applications, such as lattice parameter, degree of magnetism and mechanical strength, and which cannot be fabricated in textured form. In addition, a method for making ultra thin biaxially textured substrates with complex compositions is disclosed.
    Type: Grant
    Filed: September 19, 1997
    Date of Patent: October 12, 1999
    Assignee: Lockheed Martin Energy Research Corporation
    Inventors: Amit Goyal, Eliot D. Specht, Donald M. Kroeger, Mariappan Paranthaman
  • Patent number: 5958599
    Abstract: A biaxially textured alloy article includes a rolled and annealed biaxially textured base metal substrate characterized by an x-ray diffraction phi scan peak of no more than 20.degree. FWHM; and a biaxially textured layer of an alloy or another material on a surface thereof. The article further includes at least one of an electromagnetic device or an electro-optical device epitaxially joined to the alloy.
    Type: Grant
    Filed: January 9, 1998
    Date of Patent: September 28, 1999
    Assignee: Lockheed Martin Energy Research Corporation
    Inventors: Amit Goyal, John D. Budai, Donald M. Kroeger, David P. Norton, Eliot D. Specht, David K. Christen
  • Patent number: 5898020
    Abstract: A biaxially textured article includes a rolled and annealed, biaxially textured substrate of a metal having a face-centered cubic, body-centered cubic, or hexagonal close-packed crystalline structure; and an epitaxial superconductor or other device epitaxially deposited thereon.
    Type: Grant
    Filed: May 22, 1996
    Date of Patent: April 27, 1999
    Inventors: Amit Goyal, John D. Budai, Donald M. Kroeger, David P. Norton, Eliot D. Specht, David K. Christen
  • Patent number: 5846912
    Abstract: The present invention relate to textured YBa.sub.2 Cu.sub.3 O.sub.x (Y-123) superconductors and a process of preparing them by directional recrystallization of compacts fabricated from quenched YBCO powders at temperatures about 100.degree. C. below the peritectic temperature to provide a superconductor where more than 75% of the YBa.sub.2 Cu.sub.3 O.sub.x phase is obtained without any Y.sub.2 BaCuO.sub.5 .
    Type: Grant
    Filed: January 4, 1996
    Date of Patent: December 8, 1998
    Assignee: Lockheed Martin Energy Systems, Inc.
    Inventors: Venkat Selvamanickam, Amit Goyal, Donald M. Kroeger
  • Patent number: 5830828
    Abstract: A process for manufacturing a superconductor. The process is accomplished by depositing a superconductor precursor powder on a continuous length of a first substrate ribbon, overlaying a continuous length of a second substrate ribbon on said first substrate ribbon, and applying sufficient pressure to form a bound layered superconductor precursor between said first substrate ribbon and said second substrates ribbon. The layered superconductor precursor is then heat treated to form a super conductor layer.
    Type: Grant
    Filed: July 22, 1996
    Date of Patent: November 3, 1998
    Assignee: Martin Marietta Energy Systems, Inc.
    Inventors: Donald M. Kroeger, Frederick A. List, III
  • Patent number: 5741377
    Abstract: A biaxially textured article includes a rolled and annealed, biaxially textured substrate of a metal having a face-centered cubic, body-centered cubic, or hexagonal close-packed crystalline structure; and an epitaxial superconductor or other device epitaxially deposited thereon.
    Type: Grant
    Filed: April 10, 1995
    Date of Patent: April 21, 1998
    Assignee: Martin Marietta Energy Systems, Inc.
    Inventors: Amit Goyal, John D. Budai, Donald M. Kroeger, David P. Norton, Eliot D. Specht, David K. Christen
  • Patent number: 5739086
    Abstract: A biaxially textured article includes a rolled and annealed, biaxially textured substrate of a metal having a face-centered cubic, body-centered cubic, or hexagonal close-packed crystalline structure; and an epitaxial superconductor or other device epitaxially deposited thereon.
    Type: Grant
    Filed: May 22, 1996
    Date of Patent: April 14, 1998
    Assignee: Lockheed Martin Energy Systems, Inc.
    Inventors: Amit Goyal, John D. Budai, Donald M. Kroeger, David P. Norton, Eliot D. Specht, David K. Christen
  • Patent number: 5395821
    Abstract: Metal oxide superconductor powder precursors are prepared in an aerosol pyrolysis process. A solution of the metal cations is introduced into a furnace at 600.degree.-1000.degree. C. for 0.1 to 60 seconds. The process produces micron to submicron size powders without the usual loss of the lead stabilizer. The resulting powders have a narrow particle size distribution, a small grain size, and are readily converted to a superconducting composition upon subsequent heat treatment. The precursors are placed in a metal body deformed to form a wire or tape and heated to form a superconducting article. The fine powders permit a substantial reduction in heat treatment time, thus enabling a continuous processing of the powders into superconducting wire, tape or multifilamentary articles by the powder-in-tube process.
    Type: Grant
    Filed: October 30, 1992
    Date of Patent: March 7, 1995
    Assignee: Martin Marietta Energy Systems, Inc.
    Inventors: Donald M. Kroeger, Huey S. Hsu, Jorulf Brynestad
  • Patent number: 4581081
    Abstract: A metallic glass alloy that is either iron-based or nickel-based or based on a mixture of iron and nickel, containing lesser amounts of elements selected from the group boron, silicon carbon and phosphorous to which is added an amount of a ductility enhancing element selected from the group cerium, lanthanum, praseodymium and neodymium sufficient to increase ductility of the metallic glass upon annealing.
    Type: Grant
    Filed: September 14, 1984
    Date of Patent: April 8, 1986
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Donald M. Kroeger, Carl C. Koch