Thallium(tl)-(e.g., Tl2cabacu308) Patents (Class 505/783)
  • Patent number: 7795181
    Abstract: An oxide high temperature superconductor and method of making which includes a first buffer layer composed of CeO3 formed on a sapphire R (1, ?1, 0, 2) face substrate for reducing lattice mismatch between the sapphire R (1, ?1, 0, 2) face substrate and the oxide high temperature superconductor thin film, and a second buffer layer composed of such an oxide high temperature superconductor but in which Ba is substituted with Sr formed on the first buffer layer. The first buffer layer reduces the lattice mismatch between the sapphire R (1, ?1, 0, 2) face substrate and the oxide high temperature superconductor thin, the second buffer layer prevents an interfacial reaction with Ba, thereby permitting the epitaxial growth of an oxide high temperature superconductor thin film that excels in both crystallographic integrity and crystallographic orientation.
    Type: Grant
    Filed: September 5, 2002
    Date of Patent: September 14, 2010
    Assignee: Japan Science and Technology Agency
    Inventors: Sundaresan Athinarayanan, Hideo Ihara, Yoshiko Ihara, legal representative, Hideyo Ihara, legal representative, Hidetaka Ihara, legal representative, Gen-ei Ihara, legal representative, Chiaki Ihara, legal representative
  • Patent number: 5962373
    Abstract: A precursor is made from a plurality of materials having different vapor pressures. The precursor and a source material are placed in a closed heat treatment furnace. The source material is materials which are the same as some of the materials contained in the precursor and having particular vapor pressures. The precursor and source material is thermally treated in the furnace while the source material is being supplied, so the particular materials in the precursor have their evaporation suppressed, thereby forming compounds. The compounds may be oxide superconductors, oxide dielectric, and so on.
    Type: Grant
    Filed: March 22, 1996
    Date of Patent: October 5, 1999
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Masaaki Nemoto, Shuichi Yoshikawa, Ryokan Yuasa, Isao Yoshida, Yorinobu Yoshisato
  • Patent number: 5919735
    Abstract: A high temperature superconductor which has a layered crystal structure, which has a superconducting transition temperature, Tc, of 110 K or more, and which has a composition expressed by:Cu.sub.1-z M'.sub.z Ae.sub.2 Ca.sub.x-1 Cu.sub.x O.sub.y,where M' is at least one element selected from the group consisting of (a) trivalent ions of Tl, and (b) polyvalent ions of Mo, W, and Re,where Ae is at least one of Ba and Sr,where x ranges from 1 to 10,where y ranges from 2x+1 to 2x+4, andwhere z ranges from 0<z.ltoreq.0.5.
    Type: Grant
    Filed: October 27, 1995
    Date of Patent: July 6, 1999
    Assignee: Agency of Industrial Science and Technology
    Inventors: Hideo Ihara, Akira Iyo
  • Patent number: 5883050
    Abstract: A Hg-based superconducting cuprate film on a substrate is disclosed, which comprises a compound having the formula Hg.sub.1-x M.sub.x Ba.sub.2 Ca.sub.n-1 Cu.sub.n O.sub.y, M is a metal cation, x ranges from 0 to 1, n is an integer greater than 0, and y is an oxygen sufficiency factor having a value less than about 10.
    Type: Grant
    Filed: October 30, 1996
    Date of Patent: March 16, 1999
    Assignee: The University of Kansas
    Inventors: Sang-Ho Yun, Judy Z. Wu
  • Patent number: 5874383
    Abstract: A high temperature superconductor system having the single phase composition TlBiBaCaCuO. The system exhibits a T.sub.c of at least 116 K.
    Type: Grant
    Filed: April 8, 1997
    Date of Patent: February 23, 1999
    Assignee: University Technology Corporation
    Inventors: Allen M. Hermann, Veeraraghavan Badri
  • Patent number: 5858926
    Abstract: The present invention is directed to a process for preparing a HgBaCaCuO superconductor by annealing a precursor mixture comprising a lower member of the homologous HgBaCaCuO superconductor series, a source of calcium and a source of copper. The precursor mixture may further comprise a source of oxygen, a source of rhenium, and, if desired, a source of an additional element selected from the group consisting of halogens and metals other than mercury, barium, calcium, copper and rhenium. The process is particularly effective for preparing (Hg.sub.1-x,Re.sub.x)Ba.sub.2 Ca.sub.2 Cu.sub.3 O.sub.8-y by annealing a precursor mixture containing (Hg.sub.1-x,Re.sub.x)Ba.sub.2 Ca.sub.1 Cu.sub.2 O.sub.6-y at a temperature below about 850.degree. C., wherein x ranges up to about 0.25 and y is a rational number ranging from about negative 1 to about positive 1.
    Type: Grant
    Filed: August 23, 1996
    Date of Patent: January 12, 1999
    Assignee: Florida State University
    Inventors: Justin Schwartz, Christian H. Wolters, Kathleen M. Amm
  • Patent number: 5851954
    Abstract: A composite based on a superconducting oxide having a high critical temperature, characterized by the fact that it is constituted by glass and said oxide, the glass being such that its vitreous transition temperature is not greater than 750K, the volume fraction of the glass lying in the range 2% to 40%, said oxide existing in the glass in the form of crystallites having substantially the same orientation.
    Type: Grant
    Filed: January 3, 1992
    Date of Patent: December 22, 1998
    Assignee: Alcatel Alsthom Compagnie Generale D'Electricite
    Inventors: Michel Ribes, Christian Belouet
  • Patent number: 5849672
    Abstract: Novel superconducting oxide material containing compound oxide having a composition represented by the formula:?(Tl.sub.1-x Bi.sub.x).sub.1-p .alpha..sub.p !.sub.q Sr.sub.y Ca.sub.z Cu.sub.v O.sub.win which ".alpha." is at least one element selected from a group consisting of In, Sn, Sb, Pb, Y and lanthanide elements and "x", "y", "z", "p", "q", "v" and "w" are numbers each satisfying respective range of 0.ltoreq.x.ltoreq.1.0, 0.5.ltoreq.y.ltoreq.4.0, 0.5.ltoreq.z.ltoreq.4.5, 0.ltoreq.p.ltoreq.0.6, 0.5.ltoreq..ltoreq.3.0, and 1.0.ltoreq.v.ltoreq.5.5.
    Type: Grant
    Filed: November 30, 1995
    Date of Patent: December 15, 1998
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Yasuko Torii, Kengo Ohkura, Toshihiro Kotani
  • Patent number: 5840659
    Abstract: In order to provide a Tl--Ba--Ca--Cu--O superconductive material which can obtain a stable superconducting state and a method of preparing the same, the oxide superconductive material is expressed in the following composition formula:Tl.sub.x Ba.sub.2 Ca.sub.y Cu.sub.3 O.sub.zwhere x, y and z are in relations satisfying 1.5.ltoreq.x.ltoreq.2.0, 2.0.ltoreq.y.ltoreq.2.5, x+y=4.0 and 9.0.ltoreq.z.ltoreq.11.0, and comprises tetragonal system superconducting phases having lattice constants of a=0.385 to 0.386 nm and c longer than 3.575 nm, to exhibit zero resistance under a temperature of at least 125 K, while the method comprises a step of mixing powder raw materials in blending ratios for satisfying the above composition formula, a step of sintering the as-formed mixed powder in an oxygen jet or in the atmosphere to obtain a sintered body, and a step of annealing the sintered body in a closed atmosphere at 700.degree. to 800.degree. C. for at least 10 hours.
    Type: Grant
    Filed: March 14, 1997
    Date of Patent: November 24, 1998
    Assignees: Sumitomo Electric Industries, Ltd., Ube Industries Ltd., Matsushita Electrical Industrial Co., Ltd., International Superconductivity Technology Center
    Inventors: Tetsuyuki Kaneko, Kazuyuki Hamada, Hisao Yamauchi, Seiji Adachi, Shoji Tanaka
  • Patent number: 5776861
    Abstract: Hg,Tl-based superconductors are produced by HIPping. A new superconducting phase, having a double (Hg,Tl)-layer and the nominal composition:(Hg.sub.1-x Tl.sub.x).sub.2 (Ba.sub.1-a Sr.sub.a).sub.2 (Ca.sub.1-b Y.sub.b).sub.2 Cu.sub.3 O.sub.zwhere 0.ltoreq.x.ltoreq.0.95, 0.ltoreq.a.ltoreq.1, 0.ltoreq.b.ltoreq.1, and z is sufficient to provide said phase with a resistive and magnetic superconducting transition of 100K or above, can be produced. Either precursor oxides, or partially or fully reacted mixed oxides, can be used in the HIPping mixture.
    Type: Grant
    Filed: April 28, 1995
    Date of Patent: July 7, 1998
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Louis E. Toth, William Lechter, Earl F. Skelton, Michael Osofsky
  • Patent number: 5747099
    Abstract: A vertical two chamber reaction furnace. The furnace comprises a lower chamber having an independently operable first heating means for heating the lower chamber and a gas inlet means for admitting a gas to create an ambient atmosphere, and an upper chamber disposed above the lower chamber and having an independently operable second heating means for heating the upper chamber. Disposed between the lower chamber and the upper chamber is a vapor permeable diffusion partition. The upper chamber has a conveyor means for conveying a reactant there through. Of particular importance is the thallinating of long-length thallium-barium-calcium-copper oxide (TBCCO) or barium-calcium-copper oxide (BCCO) precursor tapes or wires conveyed through the upper chamber to thereby effectuate the deposition of vaporized thallium (being so vaporized as the first reactant in the lower chamber at a temperature between about 700.degree. and 800.degree. C.
    Type: Grant
    Filed: January 5, 1996
    Date of Patent: May 5, 1998
    Assignee: Midwest Research Institute
    Inventor: Richard D. Blaugher
  • Patent number: 5688383
    Abstract: A method for decreasing the microwave surface impedance of high-temperature superconducting thin films comprises (a) applying, preferably by spin-coating, a protective coating (preferably poly(methyl methacrylate) or polyimide) to the surface of a high-temperature superconducting thin film, such as Tl.sub.2 Ba.sub.2 CaCu.sub.2 O.sub.8 ; (b) exposing the coated thin film to low angle ion milling at an incident angle of 5.degree. to 30.degree. (preferably 10.degree. to 20.degree.) relative to the surface of the coated film; and (c) optionally including the step of removing any residual protective coating from the surface of the thin film, such as by exposure to an oxygen plasma.
    Type: Grant
    Filed: February 22, 1996
    Date of Patent: November 18, 1997
    Assignee: E. I. du Pont de Nemours and Company
    Inventor: Philip Shek Wah Pang
  • 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: 5646094
    Abstract: The present invention comprises novel superconducting materials exhibiting superconductivity at temperatures exceeding 90 K. with chemical formula Tl.sub.a Pb.sub.b Ca.sub.c Sr.sub.d R.sub.e Cu.sub.f O.sub.g where R=Y or the lanthanide rare earth elements and where 0.3.ltoreq.a,b.ltoreq.0.7, 0.05.ltoreq.c.ltoreq.1.1,2-c.ltoreq.d.ltoreq.1.95, 0.05.ltoreq.e.ltoreq.1, 1.9.ltoreq.f.ltoreq.2.1 and 6.5.ltoreq.g.ltoreq.7.5. These compounds, which are layered perovskite-like oxides, exhibit a high chemical stability, form readily into nearly single phase, do not require adjustment of oxygen stoichiometry after synthesis and compositions may be chosen allowing superconductivity at temperatures exceeding 100 K. A preferred form of the superconducting materials is the range of compositions given by the chemical formulaTl.sub.0.5+x Pb.sub.0.5-x Ca.sub.1-y Sr.sub.2-z R.sub.y+z Cu.sub.2 O.sub.7.+-..delta.where 0.ltoreq.x, 8.ltoreq.0.3, 0.ltoreq.y.ltoreq.0.95, 0.05.ltoreq.z.ltoreq.1-y of which a preferred form isTl.sub.0.
    Type: Grant
    Filed: April 13, 1995
    Date of Patent: July 8, 1997
    Inventors: Jeffrey Lewis Tallon, Murray Robert Presland
  • Patent number: 5618776
    Abstract: The invention provides certain novel metal oxide materials which exhibit superconductivity at elevated temperatures and/or which are useful in electrode, electrolyte, cell and sensor applications, or as electrochemical catalysts. The metal oxide materials are generally within the formulaR.sub.n+1-u-s A.sub.u M.sub.m+e Cu.sub.n O.sub.w (1)where n.gtoreq.0 and n is an integer or a non-integer, 1.ltoreq.m.ltoreq.2, 0.ltoreq.s.ltoreq.0.4, 0.ltoreq.e.ltoreq.4, and 2n+( 1/2)<w<(5/2)n+4, with the provisos that u is 2 for n.gtoreq.1, u is n+1 for 0.ltoreq.
    Type: Grant
    Filed: October 17, 1994
    Date of Patent: April 8, 1997
    Inventors: Jeffrey L. Tallon, Robert G. Buckley, Murray R. Presland
  • Patent number: 5597781
    Abstract: A high temperature superconductor system is provided having the following formula: M-A-B-C-D-E, wherein, M is a metallic element. A is an element in Group 3A, B is an element in Group 2A, C is another element in Group 2A, D is an element in Group 1B, and E is an element in Group 6A. In an embodiment, the high temperature superconductor has the following formula: R-Tl-Sr-Ca-Cu-O (wherein R is chosen form the group consisting of La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y). Processes for making these high temperature superconductors are also disclosed.
    Type: Grant
    Filed: February 15, 1990
    Date of Patent: January 28, 1997
    Assignee: University of Arkansas
    Inventors: Zhengzhi Sheng, Allen M. Hermann
  • Patent number: 5556830
    Abstract: Improved superconducting oxides are provided having the general formula (Hg.sub.1-x Tl.sub.x)Ba.sub.2 Ca.sub.n-1 Cu.sub.n O.sub.2n+2+.alpha. where x is from about 0.05-0.5 and n is 1, 2, 3 or 4, and .alpha. is an oxygen enrichment factor. The Tl-doped oxides exhibit very high T.sub.c and J.sub.c values.
    Type: Grant
    Filed: May 31, 1994
    Date of Patent: September 17, 1996
    Assignee: Midwest Superconductivity, Inc.
    Inventors: Guifu Sun, Kai W. Wong, Ying Xin
  • Patent number: 5550105
    Abstract: Superconducting compositions characterized by the formula (Pb.sub.a A.sub.1-a)(Sr.sub.b Ba.sub.1-b).sub.2 (Ca.sub.c B.sub.1-c)Cu.sub.2 O.sub.7 wherein at least half the A atoms are Hg and the remainder, if any, are selected from one or more of Cd, Tl and Cu, B is selected from Y and the rare earths, a is from 0.3 to 0.7, b is from 0 to 1 and c is from 0.2 to 0.5 are disclosed. The superconductive compositions display zero-resistance temperatures up to about 80K.
    Type: Grant
    Filed: January 31, 1995
    Date of Patent: August 27, 1996
    Assignee: BICC Public Limited Comapany
    Inventors: Peter P. Edwards, Shu-Fen Hu, Ru-Shi Liu, David A. Jefferson
  • 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: 5529979
    Abstract: Superconducting oxide material containing compound represented by the formula:(Tl.sub.(l-p-q) Bi.sub.p Pb.sub.q).sub.y .gamma..sub.z (.alpha..sub.(l-r) .beta..sub.r).sub.s Cu.sub.v O.sub.win which each of ".alpha." and ".gamma." is an element selected in IIa group of the periodic table, ".beta." is an element selected from a group comprising Na, K, Rb and Cs, "y", "z", "v", "w", "p", "q", "r" and "s" are numbers each satisfying respective range of 0.5.ltoreq.y.ltoreq.3.0, 0.5.ltoreq.z.ltoreq.6.0, 1.0.ltoreq.v, 5.0.ltoreq.w, 0.ltoreq.p.ltoreq.1.0, 0.ltoreq.q.ltoreq.1.0, 0.ltoreq.r.ltoreq.1.0 and 0.5.ltoreq.s.ltoreq.3.0.
    Type: Grant
    Filed: February 2, 1994
    Date of Patent: June 25, 1996
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Yasuko Torii, Hiroyuki Kusuhara
  • Patent number: 5523284
    Abstract: In accordance this invention, there is provided a process for making a bulk superconductive material. In the first step of this process, a diffusion couple is formed from superconductor oxide and impurity oxide. Thereafter, the diffusion couple is heated to a temperature in excess of 800 degrees Centigrade, cooled at a controlled rate, and annealed.
    Type: Grant
    Filed: September 30, 1994
    Date of Patent: June 4, 1996
    Assignee: Alfred University
    Inventors: James G. Fagan, Jr., Vasantha R. W. Amarakoon
  • Patent number: 5521148
    Abstract: Novel superconducting oxide material containing compound oxide having a composition represented by the formula:[(Tl.sub.1-x Bi.sub.x).sub.1-p .alpha..sub.p ].sub.q Sr.sub.y Ca.sub.z Cu.sub.v O.sub.win which ".alpha." is at least one element selected from a group consisting of In, Sn, Sb, Pb, Y and lanthanide elements and "x", "y", "z", "p", "q", and "v" are numbers each satisfying respective range of 0.1.ltoreq.x.ltoreq.0.5, 0.5.ltoreq.y.ltoreq.4.0, 0.5.ltoreq.z.ltoreq.4.5, 0.ltoreq.p.ltoreq.0.6, 0.5.ltoreq.q.ltoreq.3.0, and 1.0.ltoreq.v.ltoreq.5.5.
    Type: Grant
    Filed: October 8, 1991
    Date of Patent: May 28, 1996
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Yasuko Torii, Kengo Ohkura, Toshihiro Kotani
  • Patent number: 5516752
    Abstract: Superconducting oxide material containing compound represented by the formula:(Tl.sub.(1-p-q) Bi.sub.p Pb.sub.q).sub.y .gamma..sub.z (.alpha..sub.(1-r) .beta..sub.r).sub.s Cu.sub.v O.sub.win which each of ".alpha." and ".gamma." is an element selected in IIa group of the periodic table, ".beta." is an element selected from a group comprising Na, K, Rb and Cs, "y", "z", "v", "w", "p", "q", "r" and "s" are numbers each satisfying respective range of 0.5.ltoreq.y.ltoreq.3.0, 0.5.ltoreq.z.ltoreq.6.0, 1.0.ltoreq.v, 5.0.ltoreq.w, 0.ltoreq.p.ltoreq.1.0, 0.ltoreq.q.ltoreq.1.0, 0.ltoreq.r.ltoreq.1.0 and 0.5.ltoreq.s.ltoreq.3.0.
    Type: Grant
    Filed: November 29, 1993
    Date of Patent: May 14, 1996
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Yasuko Torii, Hiroyuki Kusuhara
  • Patent number: 5510323
    Abstract: An oxide superconductor comprising a perovskite type oxide compound of thallium, strontium, calcium and copper or thallium, strontium, balium, calcium and copper is produced by absorbing thallium in a gaseous phase into a mixture of strontium oxide or strontium oxide and barium oxide, calcium oxide, and copper oxide or a mixture of compounds capable of producing these oxides upon firing. From this superconductor are provided a superconductor wire material, tape-shaped wire material, coil, thin film, magnet, magnetic shielding material, printed circuit board, measuring device, computer, power storing device and etc.
    Type: Grant
    Filed: April 7, 1995
    Date of Patent: April 23, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Tomoichi Kamo, Seizi Takeuchi, Shinpei Matsuda, Atsuko Soeta, Takaaki Suzuki, 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: 5498594
    Abstract: A high temperature superconducting system comprising M--R--Tl--Sr--Cu--O wherein: M is at least one compound selected from the group consisting of Hg, Pb, K, and Al; and R represents rare earth metals. In one embodiment, a composition forms a 93K superconducting phase having the composition: M--R--Tl--Sr--Cu--O wherein: M is selected from the group consisting of Hg and Al; and R is a rare earth metal. In another embodiment, the composition comprises M--R--Tl--Sr--Cu--O wherein: M is selected from the group of Pb and/or K; and R is a rare earth metal.
    Type: Grant
    Filed: February 17, 1994
    Date of Patent: March 12, 1996
    Assignee: University of Arkansas
    Inventors: Zhengzhi Sheng, John Meason, Ying Xin
  • Patent number: 5492885
    Abstract: Mercury-thallium based superconductors with the formula Hg.sub.1-x Tl.sub.x Ba.sub.2 (Ca.sub.1-y Sr.sub.y).sub.2 Cu.sub.3 O.sub.8+.delta. ; change "their preparing method, in particular characterized in that it" to and a method for preparing them. The new superconductors are prepared by reacting respective ternary oxides, such as Ba.sub.2 CuO.sub.3+x and Ca.sub.1-y Sr.sub.y CuO.sub.2, to reduce the formation of an impure phase and by substituting thallium (Ti) a portion of the mercury (Hg) conventionally used in mercury-based superconductors of similar structure, in order to thermally stabilize the superconductor and provide it with a high critical current density characteristic.
    Type: Grant
    Filed: August 17, 1994
    Date of Patent: February 20, 1996
    Assignee: Korea Research Institute of Standards and Science
    Inventors: Yong H. Hur, Yong K. Park, Jong C. Park
  • Patent number: 5482917
    Abstract: A superconducting composition having the nominal formula TlM.sub.2 CuO.sub.5-x F.sub.x wherein M is Ba and x is from about 0.10 to about 0.65, or M is Sr and x is from about 0.35 to about 0.75 is disclosed.
    Type: Grant
    Filed: September 21, 1993
    Date of Patent: January 9, 1996
    Assignee: E. I. du Pont de Nemours and Company
    Inventor: Munirpallam A. Subramanian
  • Patent number: 5476836
    Abstract: Methods and reactors are described for the production of high temperature superconductor films on a variety of substrates, particularly those films which include volatile components during their manufacture. The reactors are particularly useful for producing films containing thallium. The reactors provide for relatively low volume cavities in which the substrate is disposed, and control of the thallium oxide overpressure during the processing. In a preferred embodiment, one or more holes or apertures are made in the reactor to permit thallium and thallium oxide to controllably leak from the reactor. For manufacture of double sided superconducting films, a reactor is used having top and bottom plates each with one or more holes in them. Uniform high temperature superconducting films are obtained while inhibiting reaction between the substrate and superconducting film during the processing.
    Type: Grant
    Filed: February 10, 1994
    Date of Patent: December 19, 1995
    Assignee: Superconductor Technologies, Inc.
    Inventor: Michael M. Eddy
  • Patent number: 5470821
    Abstract: Composite bulk superconducting materials having desirable physical, measured transport current density and high T.sub.c superconducting characteristics are provided which comprise a first matrix of superconducting ceramic oxide crystalline grains with a second matrix of elemental metal (gold, silver, palladium and tin) situated within the interstices between the crystalline grains. Preferably, each matrix is a continuous phase within the composite material, with the ceramic oxide preferably being present at a level of at least about 80% by weight, whereas the elemental metal is present at a level of up to about 20% by weight. In fabrication procedures, a precursor superconducting ceramic oxide is first prepared and reduced to a fine powder size; this is mixed with powdered elemental metal, and the mixture is compressed using high compaction pressures on the order of 14 tons/cm.sup.2 or greater to form a body, which is then sintered to yield the composite.
    Type: Grant
    Filed: February 15, 1995
    Date of Patent: November 28, 1995
    Assignees: The University of Kansas, Midwest Superconductivity, Inc.
    Inventors: Kai W. Wong, Xin Fei, Ying Xin, Yi-Han Kao
  • 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: 5430008
    Abstract: Superconducting materials and methods of forming superconducting materials are disclosed. Highly oxidized superconductors are heated at a relatively high temperature so as to release oxygen, which migrates out of the material, and form a non-superconducting phase which does not diffuse out of grains of the material. The material is then reoxidized at a lower temperature, leaving the non-superconducting inclusions inside a superconducting phase. The non-superconducting inclusions act as pinning centers in the superconductor, increasing the critical current thereof.
    Type: Grant
    Filed: October 28, 1991
    Date of Patent: July 4, 1995
    Assignee: The Regents of the University of California
    Inventor: Donald E. Morris
  • Patent number: 5401713
    Abstract: A new superconducting material composed mainly of compound oxide represented by the general formula:Tl.sub.h Ca.sub.j .alpha..sub.k(1-y) .beta..sub.ky Cu.sub.m O.sub.nwherein".alpha." represents Ba or Sr;".beta." represents any one of elements selected from a group comprising Na, K, Rb and Cs;"h", "j", "k", "m" and "n" are the atomic ratios each satisfies the following range:1.ltoreq.h.ltoreq.3, 1.ltoreq.j.ltoreq.3, 1.ltoreq.k.ltoreq.3,2.ltoreq.m.ltoreq.4 and 5.ltoreq.n.ltoreq.15 and"y" is a number which satisfies a range of 0.05.ltoreq.y.ltoreq.0.8.
    Type: Grant
    Filed: September 18, 1992
    Date of Patent: March 28, 1995
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventor: Yasuko Torii
  • Patent number: 5389603
    Abstract: A new class of high temperature superconductive oxides is disclosed. An exemplary member of the class has nominal composition Pb.sub.2 Sr.sub.2 Y.sub.0.5 Ca.sub.0.5 Cu.sub.3 O.sub.8 and has a transition temperature T.sub.c (onset) of about 79K.
    Type: Grant
    Filed: February 9, 1990
    Date of Patent: February 14, 1995
    Assignee: AT&T Corp.
    Inventors: Bertram J. Batlogg, Robert J. Cava
  • Patent number: 5385882
    Abstract: There is disclosed a process for preparing a thallium-containing superconductive composition. In the first step of the process, a mixture of an inorganic salt (such as potassium chloride) and a powder compositon is provided; the powder composition contains at least three separate compounds which, in combination, correspond to the stoichiometry of the super-conductor to be produced. This mixture is then charged to a closed container, raised to a temperature of from 800-959 degrees Centigrade, and heated for from about 1 to about 12 hours; thereafter, it is cooled to a temperature of 600 degrees Centigrade at a rate of at least 300 degrees Celsius per hour.
    Type: Grant
    Filed: December 9, 1992
    Date of Patent: January 31, 1995
    Assignee: Alfred Univeristy
    Inventors: Shyam S. Bayya, Robert L. Synder, Sudhakar Gopalakrishman, Walter A. Schulze
  • Patent number: 5376626
    Abstract: A superconducting switch is composed of anisotropic magnetic material. The switch has a first superconducting section, a variable resistive section and a second superconducting section. An external magnetic field is applied so that the first and second superconducting sections remain superconducting and the resistive section changes resistance when the magnetic field applied exceeds the critical field of the variable resistance section. The different critical field regions are achieved by exploiting the natural critical field anisotropy of the ceramic superconductors (a previously unobserved phenomena in metal superconductors). By making the different sections with different orientations they will exhibit different critical field valves for a given direction of applied fields. The state of the switch is changed by either increasing or decreasing the external magnetic field about the critical field value of the resistive section of the switch.
    Type: Grant
    Filed: October 2, 1992
    Date of Patent: December 27, 1994
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Alvin J. Drehman, Stephen Bachowski
  • Patent number: 5376624
    Abstract: A Josephson break junction device suitable for highly sensitive electronic detecting systems. A superconductor film such as YBa.sub.2 Al.sub.3 O.sub.7 is deposited on a substrate such as a single-crystal MgO. The film is fractured across a narrow strip by at least one indentation in the substrate juxtaposed from the strip to form a break junction. A transducer is affixed to the substrate for applying a bending movement to the substrate to regulate the distance across the gap formed at the fracture to produce a Josephson turned junction effect. Alternatively, or in addition to the transducer, a bridge of a nobel metal is applied across the gap to produce a weak-link junction.
    Type: Grant
    Filed: October 10, 1991
    Date of Patent: December 27, 1994
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Ignacio M. Perez, William R. Scott
  • Patent number: 5372990
    Abstract: Provided is an oxide superconductor in which superconducting layer is sandwiched between two blocking layers having different compositions. Available superconducting layers include a one-layer system having one Cu-O.sub.2 sheet, a two-layer system having a mediating layer sandwiched between two Cu-O.sub.2 sheets, and a three-layer system having mediating layers sandwiched individually between three Cu-O.sub.2 sheets.Since the blocking layers are of different compositions, seventy-seven kinds of oxide superconductors can be obtained.
    Type: Grant
    Filed: May 20, 1992
    Date of Patent: December 13, 1994
    Assignee: Toray Industries, Ltd.
    Inventors: Hitoshi Nobumasa, Kazuharu Shimizu
  • Patent number: 5358928
    Abstract: A process for formulating non-hysteretic and hysteretic Josephson junctions using HTS materials which results in junctions having the ability to operate at high temperatures while maintaining high uniformity and quality. The non-hysteretic Josephson junction is formed by step-etching a LaAlO.sub.3 crystal substrate and then depositing a thin film of TlCaBaCuO on the substrate, covering the step, and forming a grain boundary at the step and a subsequent Josephson junction. Once the non-hysteretic junction is formed the next step to form the hysteretic Josephson junction is to add capacitance to the system. In the current embodiment, this is accomplished by adding a thin dielectric layer, LaA1O.sub.3, followed by a cap layer of a normal metal where the cap layer is formed by first depositing a thin layer of titanium (Ti) followed by a layer of gold (Au). The dielectric layer and the normal metal cap are patterned to the desired geometry.
    Type: Grant
    Filed: September 22, 1992
    Date of Patent: October 25, 1994
    Assignee: Sandia Corporation
    Inventors: David S. Ginley, Vincent M. Hietala, Gert K. G. Hohenwarter, Jon S. Martens, Thomas A. Plut, Chris P. Tigges, Gregory A. Vawter, Thomas E. Zipperian
  • Patent number: 5342828
    Abstract: A superconducting Tl--Pb--Sr--Ca--Cu--O thin film comprised of at least one phase of the formula Tl.sub.0.5 Pb.sub.0.5 Sr.sub.2 Ca.sub.1+n Cu.sub.2+n O.sub.7+2n where n=0, 1 or 2 is disclosed, which is prepared by a process comprising sputtering an oxide film onto a dielectric substrate from an oxide target containing preselected amounts of Tl, Pb, Sr, Ca and Cu, and heating an oxygen-containing atmosphere in the deposited film in the presence of a source of thallium oxide and lead oxide and cooling the film.
    Type: Grant
    Filed: January 29, 1993
    Date of Patent: August 30, 1994
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Dennis J. Kountz, Frank M. Pellicone
  • Patent number: 5334579
    Abstract: A process for producing a superconducting material comprising a compound oxide represented by the general formula:(Ba, Ca).sub.x (.alpha., Dy).sub.1-x Tl.sub.y Cu.sub.1-y O.sub.3-zwherein ".alpha." represents Y or La; the atomic ratio of Ca to Ba is between 1% and 90%; the atomic ratio of Dy to .alpha. is between 1% and 90%; x, y and z are within the ranges of 0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1, and 0.ltoreq.z<1 respectively; and the expression of (Ba, Ca) and (.alpha., Dy) means that the respective elements occupy predetermined sites in a crystal in a predetermined proportion. The process comprises preparing a material powder, compacting the material powder and then subjecting the resulting compact to a final sintering operation and is characterized in that the material powder is(A) a powder mixture composed of powders selected from a group comprising (i) powders of elemental Ba, Cu, Ca, .alpha., Dy and Tl and (ii) powders of compounds each containing at least one of said elements Ba, Cu, Ca, .
    Type: Grant
    Filed: December 31, 1992
    Date of Patent: August 2, 1994
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Hideo Itozaki, Saburo Tanaka, Nobuhiko Fujita, Shuji Yazu, Tetsuji Jodai
  • Patent number: 5332721
    Abstract: An improved technique for the fabrication of thallium-based superconducting oxides, and particularly Tl:Ba:Ca:Cu:O 2223 oxides, is described which allows production of very pure superconductors (>95% 2223 phase) having excellent structural characteristics. The method of the invention involves first forming a self-sustaining body of starting oxides and subjecting this body to a sintering technique wherein the temperature of the body is gradually raised to a maximum level of about 850.degree.-930.degree. C., followed by maintaining the body at this temperature for a period of about 48 hours. The body is then slowly cooled to avoid distortion and loss of superconducting character. Most preferably, the sintering is a two-stage operation, wherein the body is first heated a relatively low rate (e.g., 1.degree.-10.degree. C./min.) to a temperature of about 650.degree.-750.degree. C., followed by faster heating at a higher rate to achieve the maximum sintering temperature.
    Type: Grant
    Filed: October 21, 1992
    Date of Patent: July 26, 1994
    Assignees: Midwest Superconductivity, Inc., The University of Arkansas
    Inventors: Ying Xin, Zhengzhi Sheng, Yufang Li
  • Patent number: 5328892
    Abstract: An oxide superconducting material having a composition represented by a formulaTlSr.sub.2 (Sr.sub.n-x Y.sub.x)Cu.sub.n+1 O.sub.5+2nwherein n=1 or 2 and 0.1.ltoreq.x.ltoreq.n is provided. This material has a high critical current density Jc even by sintering at a relatively low temperature of 850.degree.-880.degree. C.
    Type: Grant
    Filed: September 27, 1989
    Date of Patent: July 12, 1994
    Assignee: NEC Corporation
    Inventors: Takashi Manako, Yuichi Shimakawa, Yoshimi Kubo
  • Patent number: 5314867
    Abstract: A process of making high temperature Tl-based superconductors. The process includes the steps of reacting solid Ba--Ca--Cu-oxides with Tl.sub.2 O.sub.3 vapor. The process allows high quality Tl-based superconductors to be easily fabricated.
    Type: Grant
    Filed: July 25, 1991
    Date of Patent: May 24, 1994
    Assignee: University of Arkansas
    Inventors: Allen M. Hermann, Zhengzhi Sheng
  • Patent number: 5306698
    Abstract: Improved processes for making thin film and bulk thallium superconductors are described, as well as Tl superconductors having high critical current densities and low surface impedance. An annealing step in a reduced oxygen atmosphere is used to convert compounds containing thallium, calcium, barium and copper to a Tl-2223 superconducting phase or to convert an oxide having the nominal composition Tl.sub.2 Ca.sub.2 Ba.sub.2 Cu.sub.3 O.sub.x to a crystalline Tl-2223 phase. The oxygen pressure during annealing is controlled to be below the thermodynamic stability limit for conversion of Tl-2223 to Tl-2122 and secondary phases. Temperatures less than 880.degree. C. are used, the oxygen pressure being sufficient to prevent excess thallium loss so that the Tl content in the final Tl-2223 phase is Tl.sub.1.6-2.0. Electrical devices including SQUIDs can be made with these improved superconductors.
    Type: Grant
    Filed: October 10, 1991
    Date of Patent: April 26, 1994
    Assignee: International Business Machines Corporation
    Inventors: Byung T. Ahn, Robert B. Beyers, Wen Y. Lee
  • Patent number: 5306699
    Abstract: Methods and reactors are described for the production of high temperature superconductor films on a variety of substrates, particularly those films which include volatile components during their manufacture. The reactors are particularly useful for producing films containing thallium. The reactors provide for relatively low volume cavities in which the substrate is disposed, and control of the thallium oxide overpressure during the processing. In a preferred embodiment, one or more holes or apertures are made in the reactor to permit thallium and thallium oxide to controllably leak from the reactor. For manufacture of double sided superconducting films, a reactor is used having top and bottom plates each with one or more holes in them. Uniform high temperature superconducting films are obtained while inhibiting reaction between the substrate and superconducting film during the processing.
    Type: Grant
    Filed: October 25, 1991
    Date of Patent: April 26, 1994
    Assignee: Superconductor Technologies, Inc.
    Inventor: Michael M. Eddy
  • Patent number: 5306705
    Abstract: A non-linear superconducting junction device comprising a layer of high transient temperature superconducting material which is superconducting at an operating temperature, a layer of metal in contact with the layer of high temperature superconducting material and which remains non-superconducting at the operating temperature, and a metal material which is superconducting at the operating temperature and which forms distributed Sharvin point contacts with the metal layer.
    Type: Grant
    Filed: May 6, 1993
    Date of Patent: April 26, 1994
    Assignee: Board of Trustees of the Leland Stanford Junior University
    Inventors: Matthew J. Holcomb, William A. Little
  • Patent number: 5304537
    Abstract: A high-temperature superconducting system comprising M-Tl-Ba-Cu-O wherein: M is selected from the group consisting of Ti, Zr, and Hf. In one embodiment, the M-Tl-Ba-Cu-O system forms a high Tc phase of approximately 90 K wherein: M is selected from the group consisting of Zr and Hf. In another embodiment, a nominal ZrTl.sub.2 Ba.sub.2 Cu.sub.3 O.sub.10 sample forms a high Tc phase of above 100 K.
    Type: Grant
    Filed: February 18, 1992
    Date of Patent: April 19, 1994
    Assignee: The University of Arkansas
    Inventor: Zhengzhi Sheng
  • 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: 5298484
    Abstract: High T.sub.c superconducting compounds are made by forming a reaction mixture of the oxides of Sr, Cu, Ca and Tl, compressing these into a hardened body, and placing the hardened body into a container. The container is then evacuated and sealed. The hardened body is heated under pressure until the oxides of Sr, Ca, Cu, and Tl react to form a superconducting compound.
    Type: Grant
    Filed: March 31, 1992
    Date of Patent: March 29, 1994
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: William L. Lechter, Michael S. Osofsky, Earl F. Skelton, Louis E. Toth