Patents by Inventor Toshiya Doi

Toshiya Doi 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: 10460862
    Abstract: An object of the invention is to provide: an MgB2 superconducting thin-film wire that exhibits excellent Jc characteristics even under a 20 K magnetic field; and a method for producing thereof. The MgB2 superconducting thin-film wire includes a long substrate and an MgB2 thin film formed on the long substrate. The MgB2 thin film has a microtexture such that MgB2 columnar crystal grains stand densely together on the surface of the long substrate, and has Tc of 30 K or higher. In grain boundary regions of the MgB2 columnar crystal grains, a predetermined transition metal element is dispersed and segregated. The predetermined transition metal element is an element having a body-centered cubic lattice structure.
    Type: Grant
    Filed: October 16, 2015
    Date of Patent: October 29, 2019
    Assignee: HITACHI, LTD.
    Inventors: Toshiya Doi, Shigeru Horii, Toshiaki Kusunoki
  • Publication number: 20170301444
    Abstract: An object of the invention is to provide: an MgB2 superconducting thin-film wire that exhibits excellent Jc characteristics even under a 20 K magnetic field; and a method for producing thereof. The MgB2 superconducting thin-film wire includes a long substrate and an MgB2 thin film formed on the long substrate. The MgB2 thin film has a microtexture such that MgB2 columnar crystal grains stand densely together on the surface of the long substrate, and has Tc of 30 K or higher. In grain boundary regions of the MgB2 columnar crystal grains, a predetermined transition metal element is dispersed and segregated. The predetermined transition metal element is an element having a body-centered cubic lattice structure.
    Type: Application
    Filed: October 16, 2015
    Publication date: October 19, 2017
    Applicant: HITACHI, LTD.
    Inventors: Toshiya DOI, Shigeru HORII, Toshiaki KUSUNOKI
  • Publication number: 20080305322
    Abstract: Provided is a buffer layer of a textured substrate for forming an epitaxial film that permit the formation of an epitaxial film having a high texture. The present invention provides a buffer layer of a textured substrate for forming an epitaxial film that is provided between a base material and an epitaxial film formed on at least one surface of the base material, in which the buffer layer has a single layer structure or a multilayer structure of not less than two layers and a layer in contact with the substrate is formed from an indium tin oxide. This buffer layer can have a multilayer structure, and can be provided on the ITO layer, with at least one layer formed from nickel, nickel oxide, zirconium oxide, a rare earth oxide, magnesium oxide, strontium titanate (STO), strontium titanate-barium (SBTO), titanium nitride, silver, palladium, gold, iridium, ruthenium, rhodium, and platinum.
    Type: Application
    Filed: June 3, 2008
    Publication date: December 11, 2008
    Inventors: TOSHIYA DOI, NAOJI KASHIMA, SHIGEO NAGAYA, KUNIHIRO SHIMA
  • Publication number: 20050199983
    Abstract: A vacuum chamber the inside of which can be maintained in a substantially vacuum condition is used; a wafer in which a semiconductor wiring film is to be formed is held by a wafer substrate holder disposed in the vacuum chamber; the material of the semiconductor wiring film is evaporated by an evaporation source disposed in the vacuum chamber; and a high frequency electric power for generating a plasma in the vacuum chamber, making use of the substrate holder as an electrode is supplied from a high frequency power source.
    Type: Application
    Filed: April 6, 2005
    Publication date: September 15, 2005
    Applicant: SHINMAYWA INDUSTRIES, LTD.
    Inventors: Masao Marunaka, Toshiya Doi, Kouichi Nose, Shirou Takigawa, Kiyoshi Otake
  • Publication number: 20030153180
    Abstract: A vacuum chamber the inside of which can be maintained in a substantially vacuum condition is used; a wafer in which a semiconductor wiring film is to be formed is held by a wafer substrate holder disposed in the vacuum chamber; the material of the semiconductor wiring film is evaporated by an evaporation source disposed in the vacuum chamber; and a high frequency electric power for generating a plasma in the vacuum chamber, making use of the substrate holder as an electrode is supplied from a high frequency power source.
    Type: Application
    Filed: December 16, 2002
    Publication date: August 14, 2003
    Applicant: SHINMAYWA INDUSTRIES, LTD.
    Inventors: Masao Marunaka, Toshiya Doi, Kouichi Nose, Shirou Takigawa, Kiyoshi Otake
  • Patent number: 6316391
    Abstract: The present invention provides superconductors capable of being used at temperatures to which the superconductor can be cooled in liquid nitrogen and of carrying current in a high critical current density in a magnetic field, and superconducting apparatuses employing the superconductors and more advantageous in costs than the conventional superconducting apparatuses. A superconducting wire is formed by combining a metallic body of a cubic aggregate structure and an oxide superconducting substance. The present invention provides superconductors, superconducting wires, superconducting magnets and applied superconducting apparatuses having a high superconducting critical current density. The applied super conducting apparatuses employing the superconductors or the superconducting wires in accordance with the present invention are able to operate when cooled in liquid nitrogen-and can be manufactured at costs lower than those of the conventional superconducting apparatuses.
    Type: Grant
    Filed: March 27, 2000
    Date of Patent: November 13, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Toshiya Doi, Takesi Ozawa, Toyotaka Yuasa, Kazutoshi Higashiyama
  • Patent number: 6245455
    Abstract: A sodium-sulfur battery in which sulfur and/or sodium polysulfide are used as cathode active materials, and an electronic conductor, which are arranged in a cathode chamber between a cathode container operating concurrently as a cathode electric collector and a solid electrolyte tube, and a layer, made of a material having a superior corrosion resistance against sulfur and sodium polysulfide, is provided between said solid electrolyte tube and said electronic conductor, wherein the cathode electric collector as the electronic conductor has been improved.
    Type: Grant
    Filed: July 6, 1998
    Date of Patent: June 12, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Kazushige Kohno, Seizi Koike, Toshiya Doi, Tomoichi Kamo, Masaru Kadoshima, Kozo Sakamoto, Shigeoki Nishimura
  • Patent number: 6103669
    Abstract: This invention provides an oxide-type superconducting flat wire having a critical current density of at least 1,000 A/cm.sup.2, which comprises a Y--Ba--Cu oxide layer having a superconducting property and a silver layer surrounding the oxide layer and has so flat a cross section vertical to the longitudinal direction of the wire that the upper and lower lines between the oxide layer and the silver layers appearing on the cross section having a zone over they are parallel to each other, the thickness of the oxide layer being cold rolled in the range of 0.35 to 0.75 based on the whole thickness of the wire, the whole thickness being 0.2 mm or less, and the metal layer being deformable to follow the shrink deformation of the oxide layer when heat treated to be sintered, but rigid when used.
    Type: Grant
    Filed: May 23, 1995
    Date of Patent: August 15, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Akira Okayama, Michiya Okada, Tadaoki Morimoto, Toshimi Matsumoto, Yoshimi Yanai, Hiroshi Satoh, Toshiya Doi, Kazuhide Tanaka, Takahiko Kato
  • Patent number: 5757257
    Abstract: Superconducting magnet system using a liquid helium for its operation and a permanent current switch and a system thereof applied to the superconducting magnet system employing a permanent current loop created by a superconducting material developing superconductivity when cooled. The system includes a superconducting magnet dipped in the liquid helium, the permanent current switch for driving or interrupting the superconducting magnet, and a cryostat for accommodating the superconducting magnet and the permanent current switch, and the permanent current switch is arranged over a liquid surface of the liquid helium.
    Type: Grant
    Filed: September 20, 1994
    Date of Patent: May 26, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Toshiya Doi, Takesi Ozawa, Katsuzo Aihara, Tomoichi Kamo, Kazuhisa Mori, Nobuhiro Hara
  • Patent number: 5648322
    Abstract: A superconductive material has the formula(Tl.sub.1-X1-X2 Pb.sub.X1 Bi.sub.X2).sub..alpha. (Sr.sub.1-X3 Ba.sub.X3).sub..beta. Ca.sub..gamma. Cu.sub..delta. O.sub..xi.where0.ltoreq.X1.ltoreq.0.80.ltoreq.X2.ltoreq.0.50.ltoreq.X3.ltoreq.1.00.7.ltoreq..alpha..ltoreq.1.51.4.ltoreq..beta..ltoreq.3.00.7.ltoreq..gamma..ltoreq.4.51.4.ltoreq..delta..ltoreq.64.5.ltoreq..xi..ltoreq.170<X1+X2<1.The superconducting material may be combined with an isostructural non-superconducting material, which then acts as a pinning center. The result may also be combined with a metal. The resulting superconductor permits a high critical current density Jc to be obtained, even at relatively high magnetic flux densities.
    Type: Grant
    Filed: May 25, 1995
    Date of Patent: July 15, 1997
    Assignee: Hitachi, Ltd.
    Inventors: Toshiya Doi, Takeshi Ozawa, Kazuhide Tanaka, Toyotaka Yuasa, Tomoichi Kamo, Shinpei Matsuda
  • Patent number: 5545610
    Abstract: An oxide-based superconductor ccmprising Tl, Pb, Sr, Ca and Cu or Tl, Pb, Ba, Sr, Ca and Cu, prepared by subjecting a low melting point composition comprising the superconductor-constituting elements and a solid composition comprising the superconductor-constituting elements, prepared in advance, to reaction under melting conditions for the low melting point composition, has distinguished current pass characteristics in a high magnetic field due to improvement of electric contact among grains through reduction of non-superconductor phase, increase in crystal grain sizes (reduction of crystal boundaries), orientation of crystal and cleaning of crystal boundaries.
    Type: Grant
    Filed: September 2, 1993
    Date of Patent: August 13, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Kazutoshi Higashiyama, Toshiya Doi, Takesi Ozawa, Seizi Takeuchi, Tomoichi Kamo, Shinpei Matsuda, Yutaka Yoshida
  • Patent number: 5502029
    Abstract: Superconductors using oxide superconducting materials having pinning centers inside crystal grains are enhanced in transmissible critical current density and allowed to have a high critical current density even in the magnetic field. A superconductor is produced comprising superconducting materials having a high irreversible magnetic field where the c axes of their crystals are oriented in one direction. This can be practically realized by heat-treating a superconducting material having the composition (Tl.sub.1-X1-X2 Pb.sub.X1 Bi.sub.X2)(Sr.sub.1-X3 Ba.sub.X3).sub.2 Ca.sub.2 Cu.sub.3 O.sub.9+X4 together with Bi.sub.2 Sr.sub.2 CaCu.sub.2 O.sub.8 having a tendency of growing in the form of plate crystal. Various apparatuses capable of working under cooling with liquid nitrogen let alone with liquid helium and having a high superconducting critical current density even in a high magnetic field can be produced.
    Type: Grant
    Filed: January 26, 1994
    Date of Patent: March 26, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Toshiya Doi, Atsuko Soeta, Seizi Takeuchi, Tomoichi Kamo, Shinpei Matsuda
  • Patent number: 5462922
    Abstract: A superconductive material has the formula(Tl.sub.1-X1-x2 Pb.sub.X1 Bi.sub.X2).sub..alpha. (Sr.sub.1-X3 Ba.sub.X3).sub..beta. Ca.sub..gamma. Cu.sub..delta. O.sub..zeta.where0.ltoreq.X1.ltoreq.0.80.ltoreq.X2.ltoreq.0.50.ltoreq.X3.ltoreq.1.00.7.ltoreq..alpha..ltoreq.1.51.4.ltoreq..beta..ltoreq.3.00.7.ltoreq..gamma..ltoreq.4.51.4.ltoreq..delta..ltoreq.64.5.ltoreq..zeta..ltoreq.170<X1+X2<1.The superconducting material may be combined with an isostructural non-superconducting material, which then acts as a pinning center. The result may also be combined with a metal. The resulting superconductor permits a high critical current density Jc to be obtained, even at relatively high magnetic flux densities.
    Type: Grant
    Filed: March 27, 1992
    Date of Patent: October 31, 1995
    Assignee: Hitachi, Ltd.
    Inventors: Toshiya Doi, Takeshi Ozawa, Kazuhide Tanaka, Toyotaka Yuasa, Tomoichi Kamo, Shinpei Matsuda
  • Patent number: 5300482
    Abstract: This invention provides an oxide superconductor having a composition of the following general formula of (Tl.sub.a Bi.sub.b Pb.sub.c).sub.x (Sr.sub.d Ba.sub.e).sub.2y (Ca.sub.f Ln.sub.g).sub.y(n-1) Cu.sub.wn O.sub.2n+3+.delta., wherein Ln is at least one selected from Y and rare earth elements, n is 2, 3 or 4, -1<.delta.1, 0.8.ltoreq.x.ltoreq.1.2, 0.8.ltoreq.y.ltoreq.1.2, 0.8.ltoreq.z.ltoreq.1.2 and 0.8.ltoreq.w.ltoreq.1.2, and if a, b and c all are not zero, i.e., greater than zero, a+b+c=1, d+e=1 and f+g=1, and 0<a.ltoreq.1, 0<b.ltoreq.1, 0<c.ltoreq.1, 0.ltoreq.d.ltoreq.1, 0.ltoreq.e.ltoreq.1, 0.3.ltoreq.f.ltoreq.0.99 and 0.01.ltoreq.g.ltoreq.0.7; if b is zero, a+b+c=1, d+e=1 and f+g=1, and 0<a.ltoreq.1, 0<c.ltoreq.1, 0<d<1, 0<e<1, 0.3.ltoreq.f.ltoreq.0.99 and 0.01.ltoreq.g.ltoreq.0.7; if c is zero, a+b+c=1, d+e=1 and f+g=1, and 0<a.ltoreq.1, 0<b.ltoreq.1, 0.ltoreq.d.ltoreq.1, 0.ltoreq.e.ltoreq.1, 0.3.ltoreq.f.ltoreq.0.99 and 0.01.ltoreq.g.ltoreq.0.
    Type: Grant
    Filed: March 1, 1991
    Date of Patent: April 5, 1994
    Assignee: Hitachi, Ltd.
    Inventors: Toshiya Doi, Takaaki Suzuki, Yutaka Yoshida, Atsuko Soeta, Tomoichi Kamo, Seizi Takeuchi
  • Patent number: 5063200
    Abstract: The present invention provides a shaped superconductor article such as wire, tape or disk, comprising an oxide superconductor phase and a metal phase in a monolayered or multilayered form, the metal phase comprising a copper, iron, nickel or titanium base alloy containing 1 to 10% by weight of aluminum and having an oxygen-impermeable oxide film formed thereon, preventing the diffusion of oxygen from the oxide superconductor phase to the metal phase.
    Type: Grant
    Filed: August 9, 1988
    Date of Patent: November 5, 1991
    Assignee: Hitachi, Ltd.
    Inventors: Michiya Okada, Tadaoki Morimoto, Akira Okayama, Yoshimi Yanai, Hiroshi Satoh, Toshimi Matsumoto, Yoshiteru Chiba, Kimihiko Akahori, Takahiko Kato, Toshiya Doi, Kazuhide Tanaka