Evaporative Coating With Superconducting Material Patents (Class 505/732)
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Patent number: 5292718Abstract: Improvement in a process for fabricating a superconducting junction by depositing successively a first oxide superconductor thin layer, a non-superconducting intermediate thin film layer and a second oxide superconductor thin film layer on a substrate in this order.In the invention, the non-superconducting intermediate thin film layer is composed of MgO and the substrate is preheated at 600.degree.-650.degree. C. for at least 5 minutes in the presence of O.sub.2, and is heated at a temperature between 200.degree. and 400.degree. C. during the non-superconducting intermediate thin film layer is deposited.Type: GrantFiled: October 6, 1992Date of Patent: March 8, 1994Assignee: Sumitomo Electric Industries, Ltd.Inventors: Saburo Tanaka, Hidenori Nakanishi, Hideo Itozaki, Takashi Matsuura
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Patent number: 5290761Abstract: A process for producing thin films of superconducting material by bombarding a heated target with radiation from pulsed high energy UV laser to form a plume of target material, and depositing the plume on a substrate is disclosed.Type: GrantFiled: October 19, 1992Date of Patent: March 1, 1994Assignee: E. I. Du Pont de Nemours and CompanyInventors: Kenneth B. Keating, Stephens S. The'
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Patent number: 5286712Abstract: This invention relates to new superconducting material having a composition represented by the general formula:A.sub.u B.sub.v C.sub.w D.sub.x E.sub.Type: GrantFiled: September 30, 1992Date of Patent: February 15, 1994Assignee: Sumitomo Electric Industries, Ltd.Inventors: Nobuhiko Fujita, Tadakazu Kobayashi, Hideo Itozaki, Saburo Tanaka, Shuji Yazu, Tetsuji Jodai
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Patent number: 5281575Abstract: In manufacturing a high-temperature superconductive oxide thin film by irradiating a laser beam onto an oxide target in an atmosphere of oxygen to form the high-temperature superconductive oxide thin film on an oxide substrate, the laser beam is irradiated from a back surface of the substrate and is transmitted through the substrate, and thereafter the laser beam is irradiated onto the oxide target.Type: GrantFiled: April 21, 1992Date of Patent: January 25, 1994Assignees: International Superconductivity Technology Center, Kabushiki Kaisha Kobe Seiko Sho, Hitachi Densen Kabushiki KaishaInventors: Takashi Hase, Tadataka Morishita, Katsumi Ohata, Hirohiko Izumi
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Patent number: 5280013Abstract: A superconducting electronic circuit device, useful when impedance matching is desired, especially suited to microwave frequencies, consisting of a thin dielectric layer with superconducting layers on both sides. A superconductor such as Yttrium Barium Copper Oxide (YBCO) is formed on a first substrate such as lanthanum aluminate. A protective layer like gold is deposited on the YBCO and a second carrier substrate is bonded to the protected YBCO. The first substrate is then thinned into a thin dielectric film and a second layer of superconductor is epitaxially grown thereon to create the desired circuits.Type: GrantFiled: October 29, 1992Date of Patent: January 18, 1994Assignee: Conductus, Inc.Inventors: Nathan Newman, Aharon Kapitulnik, Brady F. Cole, Randy W. Simon
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Patent number: 5276010Abstract: A process for producing an oxide crystalline thin film having a structure in which atomic layers having different chemical compositions are laminated along the film thickness direction, the process including the steps of depositing amorphous atomic layers on a substrate, layer by layer and heating the amorphous deposit to crystallize the deposit, the respective amorphous atomic layers having the same chemical compositions as those of the corresponding atomic layers of the oxide crystal structure and being stacked in an order corresponding to the atomic lamination of the crystal structure.Type: GrantFiled: February 15, 1991Date of Patent: January 4, 1994Assignee: Fujitsu LimitedInventor: Nobuo Sasaki
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Patent number: 5273954Abstract: A method of manufacturing a superconducting ceramics elongated body by forming a longitudinally continuous superconducting layer on at least a part of the surface of a flexible ceramics elongated substrate by evaporation under the presence of oxygen ions.Type: GrantFiled: February 7, 1992Date of Patent: December 28, 1993Assignee: Fukami Patent OfficeInventors: Satoshi Takano, Kenichi Takahashi, Kenji Miyazaki, Noriyuki Yoshida, Shinji Inazawa, Noriki Hayashi
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Patent number: 5268354Abstract: A process making thin film elements of an oxide superconductor (Tl..sub.5 Pb.sub.0.5)Sr.sub.2 CaCu.sub.2 O.sub.7, (Tl..sub.5 Pb.sub.0.5)Sr.sub.2 Ca.sub.2 Cu.sub.3 O.sub.9 or a mixture thereof. The process entails forming an oxide film of a mixture of oxides of Pb, Sr, Ca and Cu in preselected amounts, placing the oxide film in a container of nonreactive metal such as gold that contains a powder of (Tl..sub.5 Pb.sub.0.5)Sr.sub.2 Ca.sub.2 Cu.sub.3 O.sub.9 superconductor, sealing the container, and heating the sealed container to a temperature of about 820.degree. C. to about 950.degree. C. for at least 1 minute.Type: GrantFiled: March 20, 1992Date of Patent: December 7, 1993Assignee: E. I. Du Pont de Nemours and ComapnyInventors: Graciela B. Blanchet-Fincher, Curtis R. Fincher, Jr., Norman Herron
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Patent number: 5264412Abstract: A method is provided for forming a thin film of an oxide superconductor on a substrate by laser ablation. Energy distribution in the section of a laser beam is homogenized within 10%. The homogenized laser beam is applied onto a target. A thin high-quality film of material ablated from the target is thus formed on a substrate which is arranged to face the target.Type: GrantFiled: August 12, 1991Date of Patent: November 23, 1993Assignee: Sumitomo Electric Industries, Ltd.Inventors: Nobuhiro Ota, Tatsuoki Nagaishi, Naoji Fujimori
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Patent number: 5260265Abstract: An Improved method of manufacturing superconducting ceramics in the form of a thin film are described. The thin film is first formed of a superimposed structure composed of three films which contain a rare earth metal, an alkalline earth metal and copper respectively. Then the superimposed thin film is fired to convert to a superconducting film.Type: GrantFiled: January 10, 1992Date of Patent: November 9, 1993Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventor: Shunpei Yamazaki
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Patent number: 5260267Abstract: A superconducting thin film of Bi-containing compound oxide deposited on a substrate, a buffer layer made of Bi.sub.2 O.sub.3 being interposed between the superconducting thin film and the substrate.Type: GrantFiled: August 4, 1992Date of Patent: November 9, 1993Assignee: Sumitomo Electric Industries, Ltd.Inventors: Keizo Harada, Hideo Itozaki
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Patent number: 5258366Abstract: Improvement in a method for preparing a superconducting thin film of compound oxide on a substrate (6) by laser evaporation technique. A rear surface of a target (7) used is cooled forcedly by a cooling system (9) during film formation.Type: GrantFiled: July 29, 1992Date of Patent: November 2, 1993Assignee: Sumitomo Electric Industries, Ltd.Inventors: Tatsuoki Nagaishi, Hidenori Nakanishi, Saburo Tanaka, Hideo Itozaki
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Patent number: 5252547Abstract: An outer surface of a superconducting film of compound oxide such as YBa.sub.2 Cu.sub.3 O.sub.7-.delta. is protected with a protective layer which is composed of any one of (i) oxide of metal such as MgO, CaO, SrO etc, (ii) carbide such as SiC, or (iii) nitride such as BN.Type: GrantFiled: October 9, 1990Date of Patent: October 12, 1993Assignee: Sumitomo Electric Industries, Ltd.Inventors: Hideo Itozaki, Saburo Tanaka, Nobuhiko Fujita, Shuji Yazu, Tetsuji Jodai
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Patent number: 5252553Abstract: In order to prepare a good quality crystalline thin film of compound oxide superconductor on a silicon wafer, before the thin film of compound oxide superconductor is deposited on the silicon wafer, the silicon wafer is first heated at a temperature of higher than 900.degree. C. in a high vacuum of less than 10.sup.-6 Torr, then, a thin film of ZrO.sub.2 is deposited on the silicon wafer, and finally, the thin film of ZrO.sub.2 deposited on the silicon wafer is annealed in air at a temperature of 800.degree. to 850.degree. C.Type: GrantFiled: May 20, 1992Date of Patent: October 12, 1993Assignee: Sumitomo Electric Industries, Ltd.Inventors: Hidenori Nakanishi, Shinichi Shikata, Hideo Itozaki
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Patent number: 5250511Abstract: Method for preparing a superconducting thin film of compound oxide having improved properties on a substrate by laser evaporation technique. A target has a surface area which is smaller than an irradiation area of a spot of a laser beam used, so that whole surface of the surface is irradiated with the laser beam.Type: GrantFiled: July 29, 1992Date of Patent: October 5, 1993Assignee: Sumitomo Electric Industries, Ltd.Inventors: Tatsuoki Nagaishi, Hidenori Nakanishi, Saburo Tanaka, Hideo Itozaki
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Patent number: 5248659Abstract: In a process for preparing a thin film of a Bi-Sr-Ca-Cu-O based oxide superconductor by a laser ablation method in which a target is irradiated with a pulsed laser beam to grow a thin film on a substrate positioned to face the target, the improvement wherein the pulse rate of the pulsed laser beam is adjusted to 0.01-10 Hz and the application of the laser beam is interrupted at each time a superconducting thin oxide film is grown to a thickness equivalent to one half the unit cell or one unit cell of a Bi-Sr-Ca-Cu-O based oxide superconductor, whereby a thin film of the oxide superconductor is grown at an average growth rate of no more than 0.5 .ANG./sec.Type: GrantFiled: November 14, 1991Date of Patent: September 28, 1993Assignee: Sumitomo Electric Industries, Ltd.Inventors: Tatsuoki Nagaishi, Hisao Hattori, Hideo Itozaki
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Patent number: 5248658Abstract: A superconducting ceramic film is deposited on a substrate by sputtering. In virtue of the low thermal conductivity of ceramic, a laser beam is irradiated to the ceramic film in order to remove the irradiated portion by sublimation and produce a pattern on the ceramic film.Type: GrantFiled: September 23, 1991Date of Patent: September 28, 1993Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventor: Shumpei Yamazaki
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Patent number: 5248662Abstract: In order to prepare an elongated oxide superconducting material which exhibits a high critical current density, a tape-type substrate (7) of silver, for example, formed by unidirectional solidification is prepared and an excimer laser beam (9) is applied to target (8) of an oxide superconductor to deposit atoms and/or molecules being scattered from the target (8) on the substrate (7), thereby forming an oxide superconducting film on the substrate (7).Type: GrantFiled: January 31, 1992Date of Patent: September 28, 1993Assignees: Sumitomo Electric Industries, Tokyo Electric Power CompanyInventors: Noriyuki Yoshida, Satoshi Takano, Tsukushi Hara, Kiyoshi Okaniwa, Takahiko Yamamoto
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Patent number: 5240904Abstract: Improvement in a process for preparing a-axis oriented thin film of high-Tc oxide superconducting material by laser evaporation method. Before the a-axis oriented thin film of oxide superconducting material is deposited by laser evaporation method, an under-layer having an a-axis orientation of the crystal of the same oxide superconducting material is deposited on a substrate previously by sputtering.Type: GrantFiled: May 30, 1991Date of Patent: August 31, 1993Assignee: Sumitomo Electric Industries, Ltd.Inventors: Saburo Tanaka, Hidenori Nakanishi, Hideo Itozaki
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Patent number: 5236895Abstract: There is provided in a process for depositing a metal oxide superconducting film on a substrate by laser sputtering, the improvement which comprises carrying out the deposition of the metal oxide superconducting film in the presence of a gas having higher oxidation potential than oxygen.Type: GrantFiled: July 23, 1991Date of Patent: August 17, 1993Assignee: Kawasaki Jukogyo Kabushiki KaishaInventors: Yukio Nishiyama, Shichio Kawai, Tomoji Kawai, Hitoshi Tabata, Osamu Murata, Junzo Fujioka
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Patent number: 5234901Abstract: Improvement in a process for depositing a thin film on an oxide superconductor thin film deposited previously on a substrate.A surface of the thin film of oxide superconductor is irradiated with laser beam pulses in high-vacuum of lower than 1.times.10.sup.-6 Torr before said another thin film is deposited thereon.The invention is applicable to fabrication of electronics devices such as Josephson element or superconducting transistors.Type: GrantFiled: July 12, 1991Date of Patent: August 10, 1993Assignee: Sumitomo Electric Industries, Ltd.Inventors: Mitsuchika Saitoh, Michitomo Iiyama
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Patent number: 5231077Abstract: A method for fabricating an active device comprises the steps of injecting particles into a single crystal substrate of a semiconductor material at a predetermined depth from the surface, annealing the substrate that contains the particles to form an insulator layer within the substrate, generally in correspondence to the predetermined depth, the step of annealing including a step of forming a single crystal semiconductor layer of a semiconductor material identical in composition with the substrate, on the insulator layer that is formed by the annealing, starting a deposition of a layer of an oxide superconductor on the semiconductor layer, growing the oxide superconductor layer while maintaining an epitaxial relationship with respect to the substrate; and converting the semiconductor layer to an oxide layer simultaneously to the growth of the oxide superconductor layer.Type: GrantFiled: August 8, 1991Date of Patent: July 27, 1993Assignee: Nobuo SasakiInventor: Nobuo Sasaki
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Patent number: 5225396Abstract: A method for forming an oxide superconducting film is disclosed. A substrate member comprising an oxygen ion conductor and a material provided thereon having oxygen permeability and good fitting of lattice constant to the oxide superconducting film is prepared, and then an oxide superconducting film is formed on the substrate member. During the formation of the superconducting film, electric current is made to flow through the substrate member, whereby oxygen is supplied to the superconducting film.Type: GrantFiled: July 24, 1991Date of Patent: July 6, 1993Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventor: Hisashi Ohtani
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Patent number: 5215960Abstract: In a method of manufacturing a superconducting device which has a first thin film of oxide superconductor material formed on a substrate and a second thin film formed on the first thin film of oxide superconductor material, after the second thin film is deposited on the first thin film of oxide superconductor material, a multi-layer structure formed of the first and second thin films is patterned so that a side surface of the first thin film is exposed. In this condition, the whole of the substrate is heated in an O.sub.2 atmosphere or in an O.sub.3 atmosphere so that oxygen is entrapped into the first thin film of oxide superconductor material. Thereafter, the patterned multi-layer structure is preferably covered with a protection coating.Type: GrantFiled: July 16, 1991Date of Patent: June 1, 1993Assignee: Sumitomo Electric Industries, Ltd.Inventors: Sou Tanaka, Mitsuchika Saitoh, Michitomo Iiyama
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Patent number: 5212147Abstract: A method of forming a patterned in-situ photoconductive film on a substrate including providing a patterned photoresist layer on upper and lower metallic layers formed on a substrate. The patterned photoresist layer is used to form an opening in the upper layer. The pattern in the upper layer thereby has an opening having a geometry substantially similar to a desired pattern of photoconductive material to be formed on the substrate. A portion of the lower layer is removed to form cantilevered regions of the upper layer adjacent to the opening. Superconductive material is then deposited on the substrate by directing the material through the opening at an angle generally perpendicular to the substrate. The superconductive film on the substrate within the lower layer is coated with a polymer. The upper and lower layers and all superconductive material on those layers are removed to leave the polymer-encapsulated superconductive material on the substrate.Type: GrantFiled: May 15, 1991Date of Patent: May 18, 1993Assignee: Hewlett-Packard CompanyInventor: James R. Sheats
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Patent number: 5212151Abstract: An oxide superconducting thin film formed by laser ablation comprises a matrix formed of c-axis oriented superconducting phases and foreign phases which are different in crystal orientation from the matrix. In order to improve critical current density of the oxide superconducting thin film, preferably selected are such conditions that the size of each superconducting phase in its a-b plane is not more than 0.1 .mu.m in diameter, the size of each superconducting phase along its c-axis direction is equal to the thickness of the oxide superconducting thin film, the foreign phases at least partially pass through the oxide superconducting thin film along the direction of thickness, the size of each foreign phase is at least 0.01 .mu.m and not more than 5 .mu.m in diameter, each foreign phase has an a-axis or a c-axis perpendicularly oriented with respect to the major surface of the oxide superconducting thin film, and the like.Type: GrantFiled: December 7, 1990Date of Patent: May 18, 1993Assignee: Sumitomo Electric Industries, Ltd.Inventors: Satoshi Takano, Shigeru Okuda, Noriyuki Yoshida, Tsukushi Hara, Kiyoshi Okaniwa, Takahiko Yamamoto
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Patent number: 5212148Abstract: A method of manufacturing a layer of a superconducting high-T.sub.c -material. For this purpose, an appropriate target material is deposited on a predetermined substrate by a pulsed laser with a wavelength in the ultraviolet range and, by applying a heat treatment and an oxygen treatment, the desired superconducting metal-oxide phase is formed with an ordered crystal structure. The heat treatment and oxygen treatment are performed simultaneously during the vaporizing step, whereby a power density of the laser radiation of over 3 J/cm.sup.2 at the target material is provided, the pulse power of the laser is at least 1.5 J/pulse, the temperature of the substrate is raised to 600.degree. C. to 800.degree. C., and an oxygen atmosphere of between 0.02 mbar and 1 mbar is provided.Type: GrantFiled: May 3, 1989Date of Patent: May 18, 1993Assignee: Siemens AktiengesellschaftInventors: Bernhard Roas, Gerhard Endres, Ludwig Schultz
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Process for preparing a single phase Bi-containing superconducting thin oxide film by laser ablation
Patent number: 5210070Abstract: A process of preparing a superconducting thin oxide film includes irradiating a target containing Bi, Sr, Ca and Cu with a laser beam to prepare a thin film of superconducting Bi.sub.2 Sr.sub.2 Ca.sub.2 Cu.sub.3 O.sub.x oxide or a thin film of superconducting Bi.sub.2 Sr.sub.2 Ca.sub.1 Cu.sub.2 O.sub.y oxide on a substrate. The process is characterized in that the target containing Bi, Sr, Ca and Cu in an atomic ratio of 2:2:2:3 is positioned to face the substrate, and the laser beam is irradiated to the target in an atmosphere having an oxygen partial pressure of 0.01-1 Torr while the temperature of the substrate is maintained in a given temperature range suitable for growing the respective superconducting thin oxide films.Type: GrantFiled: November 14, 1991Date of Patent: May 11, 1993Assignee: Sumitomo Electric Industries, Ltd.Inventors: Tatsuoki Nagaishi, Hisao Hattori, Hideo Itozaki -
Patent number: 5206216Abstract: Disclosed herein is a method of and an apparatus for fabricating an oxide superconducting wire which comprises a tape-type long base material and an oxide superconducting film formed thereon. The oxide superconducting film is formed by laser ablation of applying a laser beam (2) onto a target (4) while translating a long base material (6) along its longitudinal direction and depositing atoms and/or molecules scattered from the target (4) on the base material (6).Type: GrantFiled: September 16, 1991Date of Patent: April 27, 1993Assignee: Sumitomo Electric Industries, Ltd.Inventor: Noriyuki Yoshida
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Patent number: 5206212Abstract: A laser beam (2) is applied to a target (1) of an oxide superconductive material, to deposit atoms and/or molecules which are scattered from the target (1) on a first portion (4) of a substrate (3) under an atmosphere containing oxygen for a start. Then, the substrate (3) is moved to deposit atoms and/or molecules scattered from the target (10) on a second portion, which is different form the first portion (4) of the substrate (3), under the atmosphere containing oxygen. At this time, the first portion (4) is subjected to oxygen annealing. These deposition steps are repeated until an oxide superconducting film of a desired thickness is obtained.Type: GrantFiled: January 9, 1992Date of Patent: April 27, 1993Assignee: Sumitomo Electric Industries, Ltd.Inventor: Shigeru Okuda
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Patent number: 5198414Abstract: A laser ablation method for forming a fluorinated superconducting Y-Ba-Cu-O thin film on a sapphire substrate is disclosed, which comprises the steps of: (1) depositing a barrier layer of BaAl.sub.2 O.sub.4 on the sapphire substrate; (2) placing the coated substrate and a tagret in a deposition chamber, said target including fluorine, barium, yttrium, copper and oxygen; (3) providing a background atmosphere including at least partial pressure of O.sub.2 within the chamber; (4) heating the coated substrate to a temperature above ambient; (5) laser-ablating the target material onto the heated substrate while controlling the partial pressure of O.sub.2 in said background atmosphere and the temperature of said heated substrate so that the as-deposited thin film on said substrate is superconductive.Type: GrantFiled: October 1, 1991Date of Patent: March 30, 1993Assignee: Energy Conversion Devices, Inc.Inventors: Stanford R. Ovshinsky, Rosa Young, Gerard Van der Leeden, Benjamin S. Chao
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Patent number: 5196398Abstract: Improvement in heat-treatment of a superconducting thin film of thallium type compound oxide deposited on a substrate by PVD or CVD. In the invention, the heat-treatment is effected at a temperature between 880.degree. C. and 920.degree. C. for a predetermined time duration under such a condition that the partial pressure of thallium oxide becomes higher than the saturated vapour pressure of thallium oxide at said temperature.Type: GrantFiled: July 30, 1991Date of Patent: March 23, 1993Assignee: Sumitomo Electric Industries, Ltd.Inventors: Keizo Harada, Hideo Itozaki, Shuji Yazu
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Patent number: 5196395Abstract: A method for generating repeatable and reproducible crystallographic grain-boundary junctions is provided by forming a film on a crystalline substrate which has intersecting faces. In a preferred embodiment, a single crystal substrate is etched by an anisotropic etchant to provide a "V"-groove in one face, and an epitaxial superconducting film is grown on the faces of the V-groove. In another preferred embodiment, a step is etched with an anisotropic etch, and an epitaxial superconducting film grown on the step. Grain-boundary junctions are formed at the points of intersection of the faces with each other, or with the faces and the surface of the substrate. The film may be patterned and etched in the area of the boundary junction to form useful devices.Type: GrantFiled: March 4, 1991Date of Patent: March 23, 1993Assignee: Superconductor Technologies, Inc.Inventors: Timothy W. James, Julia S. Fleming
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Patent number: 5194419Abstract: A method for manufacturing a superconductive multilayer circuit has a first thin film forming step for forming a thin film, which is composed of superconductive material or a similar material thereto, on a substrate, a first circuit layer forming step for forming a superconductive circuit by discharging a specific component from a predetermined part of the thin film or implanting the component in the thin film, a second thin film forming step for forming a thin film, which is composed of a superconducting material or the simulant thereto, on the first circuit layer, and a second circuit layer forming step for forming a superconductive circuit by removing a specific component from a predetermined part of the thin film or implanting the component in the thin film.Type: GrantFiled: July 18, 1990Date of Patent: March 16, 1993Assignee: The Furukawa Electric Co., Ltd.Inventors: Shoji Shiga, Nakahiro Harada, Kiyoshi Yamamoto, Koki Sato
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Patent number: 5187147Abstract: A process for producing a freestanding high Tc superconducting thin film is disclosed, which comprises providing a carbon substrate, depositing a high Tc superconducting thin film on the substrate and removing the carbon substrate by converting the carbon substrate to a gaseous composition at a temperature insufficient to cause thermal damage to said superconducting thin film but greater then 500.degree. C. in an oxygen containing atmosphere.Type: GrantFiled: October 1, 1991Date of Patent: February 16, 1993Assignee: Florida State UniversityInventors: Hon-Kie Ng, Snezana Kilibarda-Dalafave
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Patent number: 5173474Abstract: An HTSC material epitaxially deposited on a YSZ buffer layer on a surface of a monocrystalline silicon substrate has a zero resistance transition temperature of at least 85.degree. K., a transition width (10-90%) of no more than 1.0.degree. K., a resistivity at 300.degree. K. of no more than 300 micro-ohms-centimeter and a resistivity ratio (at 300.degree. K./100.degree. K.) of 3.0.+-.0.2. The surface of the silicon substrate is cleaned using a spin-etch process to produce an atomically clean surface terminated with an atomic layer of an element such as hydrogen with does not react with silicon. The substrate can be moved to a deposition chamber without contamination. The hydrogen is evaporated in the chamber, and then YSZ is epitaxially deposited preferably by laser ablation. Thereafter, the HTSC material, such as YBCO, is epitaxially deposited preferably by laser ablation. The structure is then cooled in an atmosphere of oxygen.Type: GrantFiled: March 11, 1991Date of Patent: December 22, 1992Assignees: Xerox Corporation, President and Board of Trustees of Santa Clara College, Board of Trustees of the Leland Stanford Junior UniversityInventors: George A. N. Connell, David B. Fenner, James B. Boyce, David K. Fork
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Patent number: 5168097Abstract: The process for forming an ultrafine-particle film according to this invention is characterized by irradiating the surface of a target of a raw material with laser energy in a predetermined atmosphere under conditions where a plume is generated, exposing a substrate (a base material) directly to the plume generated, and thereby forming a film. The substrate is positioned in the plume at a distance, from the surface of the target of the raw material, of at least the mean free path of atoms and/or molecules of the raw material (or components thereof). By so positioning the substrate, ultrafine particles of the raw material are deposited on the substrate. The plume containing a large amount of ultrafine particles moves at a high speed; and exposure of the substrate, at the specified position relative to the target, to the plume causes strong adhesion of ultrafine particles contained in the plume to the substrate, resulting in formation of a film.Type: GrantFiled: February 27, 1991Date of Patent: December 1, 1992Assignee: Hitachi, Ltd.Inventors: Takeshi Araya, Akira Matsunawa, Seiji Katayama, Susumu Hioki, Mitsuaki Haneda, Ryoji Okada
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Patent number: 5158931Abstract: A laser beam 5 is directed to a target made of an oxide superconductor to allow a target spot which is irradiated with the beam to be evaporated and a matter which is evaporated to be deposited as a thin film on the surface of a substrate 3 at which time excited oxygen is supplied to or near a thin film deposition site on the substrate 3. In this way, an oxide superconductor thin film is formed on the substrate with oxygen atoms incorporated in the crystal structure of the thin film.Type: GrantFiled: November 16, 1989Date of Patent: October 27, 1992Assignee: Kabushiki Kaisha ToshibaInventors: Etsuo Noda, Setsuo Suzuki, Osami Morimiya, Kazuo Hayashi
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Patent number: 5151408Abstract: A process for preparing a-axis oriented thin film of oxide superconducting material on a substrate by two steps. In the first step, an under-layer of an oxide superconducting material is deposited on the substrate under such a condition that the substrate is heated at a temperature which is suitable to realize an a-axis orientation of crystal of the oxide superconducting material. In the second step, an upper-layer of the same oxide superconducting material is deposited on a surface of the resulting under-layer under such a condition that the substrate is heated at a temperature which is lowered by 10.degree. to 100.degree. C. than the temperature which is used in the first step.Type: GrantFiled: March 11, 1991Date of Patent: September 29, 1992Assignee: Sumitomo Electric Industries, Ltd.Inventors: Saburo Tanaka, Hidenori Nakanishi, Hideo Itozaki
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Patent number: 5145713Abstract: A method of growing KTa.sub.x Nb.sub.1-x O.sub.3 by pulsed laser evaporation. In order to compensate for the volatile K, two targets are prepared, one of sintered oxide powder having K, Ta, and Nb in amounts stoichiometric to KTa.sub.x Nb.sub.1-x O.sub.3 and the other of melt-grown KNO.sub.3. The method can also be used to form other complex materials having volatile components using a variety of sputtering growth techniques. The two targets are mounted on a rotating target holder and are alternately ablated by the laser beam. The KNO.sub.3 provides excess K, thus allowing the growth of a stoichiometric film. The method can be applied to many complex materials for which some of the components are volatile.Type: GrantFiled: December 21, 1990Date of Patent: September 8, 1992Assignees: Bell Communications Research, Inc., Heinrich-Hertz-InstitutInventors: Thirumalai Venkatesan, Sukru Yilmaz
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Patent number: 5143894Abstract: A method is disclosed for forming a patterned oxide superconducting film wherein a selected region of a ternary metal oxide superconducting film is irradiated in a controlled atmosphere with photons so as to become non-superconductive.Type: GrantFiled: August 16, 1989Date of Patent: September 1, 1992Inventors: Mordechai Rothschild, Daniel J. Ehrlich, Jerry G. Black
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Patent number: 5141917Abstract: A perovskite type superconductor film having a high content, almost a single phase, of the high Tc phase is formed by the steps of: depositing at least one first film of a first material (e.g., a composite oxide of Bi-Sr-Ca-Cu-O system or Tl-Ba-Ca-Cu-O system) constituting a perovskite type superconductor over a substrate; depositing at least one second film of a second material containing an oxide or element (Bi.sub.2 O.sub.3, Tl.sub.2 O.sub.3, PbO.sub.x, etc., particularly PbO.sub.x) having a vapor pressure of more than 10 .sup.-4 Pa at 800.degree. C. at least as a main component over the substrate; to thereby form a stack of the first and second films; and heat treating the stack of the first and second films to form the perovskite type superconductor film on the substrate. Further, preferred compositions of the as-deposited films or stack are determined.Type: GrantFiled: August 9, 1990Date of Patent: August 25, 1992Assignee: Fujitsu LimitedInventors: Atsushi Tanaka, Nobuo Kamehara, Koichi Niwa
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Patent number: 5130296Abstract: When an oxide superconducting thin film is formed on a substrate by a vapor phase method such as laser ablation, for example, a plurality of grooves are formed on the substrate by photolithography or beam application in the same direction with an average groove-to-groove pitch of not more than 10 .mu.m, so that the oxide superconducting thin film is formed on a surface provided with such a plurality of grooves. Thus promoted is growth of crystals of the oxide superconducting thin film in parallel with the grooves, whereby respective directions of a-axes and c-axes are regulated to some extent. This improves critical current density of the oxide superconducting thin film.Type: GrantFiled: March 29, 1991Date of Patent: July 14, 1992Assignee: Sumitomo Electric Industries, Ltd.Inventors: Satoshi Takano, Shigeru Okuda, Noriyuki Yoshida, Noriki Hayashi, Kenichi Sato
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Patent number: 5114906Abstract: Improvement in a superconducting thin film of a superconducting compound oxide containing thallium (Tl) deposited on a substrate, characterized in that the superconducting thin film is deposited by PVD on {110} plane of a single crystal of magnesium oxide (MgO).Type: GrantFiled: March 4, 1991Date of Patent: May 19, 1992Assignee: Sumitomo Electric Industries, Ltd.Inventors: Kenjiro Higaki, Keizo Harada, Naoji Fujimori, Hideo Itozaki, Shuji Yazu
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Patent number: 5110791Abstract: A method for producing an oxide superconductor comprises the steps of: forming on a substrate a layer of elements deficient in at least one of the elements composing a desired oxide superconductor and immersing the layer formed substrate into a solution containing a supplementary element which is at least one of the deficient oxide superconductor composing elements.Type: GrantFiled: September 18, 1990Date of Patent: May 5, 1992Assignee: Fujitsu LimitedInventor: Seigen Ri
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Patent number: 5108984Abstract: A thin film of an oxide superconductor having a homogeneous composition and less oxygen defects is produced by independently vaporizing at least one material selected from the group consisting of the elements of Ia, IIa and IIIa groups of the periodic table and their compounds and at least one material selected from the group consisting of the elements of Ib, IIb and IIIb groups of the periodic table and their compounds in the presence of molecular oxygen and depositing the vaporized materials together with oxygen on a substrate to form a thin film of the oxide superconductor.Type: GrantFiled: December 19, 1990Date of Patent: April 28, 1992Assignee: Sumitomo Electric Industries, Ltd.Inventors: Jun Shioya, Yoichi Yamaguchi, Akira Mizoguchi, Noriyuki Yoshida, Kenichi Takahashi, Kenji Miyazaki, Satoshi Takano, Noriki Hayashi
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Patent number: 5100863Abstract: An improved method of manufacturing superconducting ceramics in the form of a thin film are described. The thin film is first formed of a superimposed structure composed of three films which contain a rare earth metal, an alkaline metal and copper respectively. Then the superimposed thin film is fired to convert to superconducting film.Type: GrantFiled: March 23, 1988Date of Patent: March 31, 1992Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventor: Shumpei Yamazaki
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Patent number: 5096880Abstract: A process is described for enhancing superconductor characteristics by application of strong magnetic and/or electric fields to the constituent component materials from which ceramic superconductors are being formed and during the time that these superconductors are being synthesized. This process has particular applicability to the production of superconducting oxide ceramics such as the cuprates. The required magnetic fields are on the order of 1-10 tesla and the required electric fields are on the order of 0.1-1 MV/cm. The fields act as ordering mechanisms and induce grain orientation. The magnetic field aligns the magnetic moment of the grains. The electric field induces electric polarization in the grains and then aligns them. The superconducting structure formation occurs during the sintering, cooling and annealing phases of the fabrication process. Superconductivity is strongly affected by the oxygen stoichiometry in the lattice elemental cell. Applied electric fields cause elongation of the unit cell.Type: GrantFiled: April 20, 1990Date of Patent: March 17, 1992Assignee: General Dynamics Corp./Electronics DivisionInventor: Theodore W. Rybka
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Patent number: 5096881Abstract: The present invention provides a method for making Tl-Ca-Ba-Cu-O superconductive materials in a film shape. Pursuant to the method, after placing a Ca.sub.2 Ba.sub.2 Cu.sub.3 O.sub.7 powder onto some suitable substrate, such as platinum or copper, the substrate and powder are rolled between two rollers until a desired thickness is achieved. The film can then be taken off the substrate. Thallium oxide is then evaporated on the precursor film to make superconductive films. The Tl.sub.2 O.sub.3 can be evaporated in a furnace or vacuum.Type: GrantFiled: March 15, 1990Date of Patent: March 17, 1992Assignee: The University of ArkansasInventors: Qamar A. Shams, Allen M. Hermann, Zhengzhi Sheng
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Patent number: 5087608Abstract: A method for the passivation of superconductive rare earth cuprates involves depositing thereon a thin film of an amorphous or diamond-like carbon film of a thickness ranging from 100 .ANG. to 10 microns. The cuprate film may be in the as-deposited form, so necessitating a subsequent annealing step to convert the film to a superconducting phase and to remove the carbon.Type: GrantFiled: December 28, 1989Date of Patent: February 11, 1992Assignee: Bell Communications Research, Inc.Inventors: Siu W. Chan, Leonilda A. Farrow