Abstract: A rapid single-flux-quantum RSFQ logic circuit includes a first circuit portion having a first end grounded and having in-series connected first and second Josephson junctions. A second circuit portion has a first end grounded and has in-series connected third and fourth Josephson junctions. A first inductance element connects a second end of the first circuit portion to a second end of the second circuit portion. A tap is provided in the first inductance element, an input current signal being supplied to the tap. A bias current source is connected to a first connection node between the first and second Josephson junctions. A second inductance element connects the first connection node to a second connection node between the third and fourth Josephson junctions. A superconducting quantum interference device has fifth and sixth Josephson junctions and is coupled to the second inductance element through a magnetic field.

Abstract: There is provided a superconducting device including a substrate, a first superconductor layer supported by the substrate and containing Ln, AE, M and O, and a second superconductor layer containing a material represented by a formula of (Yb1−yLn′y)AE′2M′3Oz, the first and second superconductor layers forming a junction, and atomic planes each including M and O in the first superconductor layer and atomic planes each including M′ and O in the second superconductor layer being discontinuous to each other in a position of the junction, wherein each of Ln and Ln′ represents at least one metal of Y and lanthanoids, each of AE and AE′ represents at least one of alkaline earth metals, each of M and M′ represents a metal which contains 80 atomic % or more of Cu, y represents a value between 0 and 0.9, and z represents a value between 6.0 and 8.0.

Abstract: A high temperature superconducting device includes a substrate (1), a ground plane (2) formed on the substrate with a prescribed pattern and made of an oxidic superconducting material, and a dielectric layer (3) formed on the substrate so as to surround the ground plane. The dielectric layer has the same crystal structure as the oxidic superconducting material and with a heat absorbance closer to that of the oxidic superconducting material than to that of the substrate.

Abstract: A superconductor having at least one Hg—M—Cu—O (M=Ba, Sr and/or Ca) superconducting film provided on a substrate and having a thickness of between 300 Å to 950 Å. The superconductor may be prepared by forming, on a substrate, a precursor laminate composed of a first, M—Cu—O film and a second, Hg—O film. The precursor laminate film-bearing substrate is placed in a closed vacuum chamber together with a first pellet of HgO, MO and CuO and a second pellet of MO and CuO. The contents in the chamber are heated to form, on the substrate, a superconducting Hg—M—Cu—O film. The thickness of the first M—Cu—O film of the precursor is controlled so that the thickness of the superconducting Hg—M—Cu—O film is in the range of between 300 Å to 950 Å.

Abstract: There is provided a power lead for a superconductive magnet capable of controlling the invasion of heat to liquid helium for storing superconductive coils therein and of sufficiently feeding power to the superconductive coils. The power lead for a superconductive magnet of a superconductor magneto unit for supplying a current to the superconductive coils which are cooled at a liquid helium temperature through a radiant heat shielded section which is cooled at a liquid nitrogen temperature, wherein at least a part of sections positioned inside the radiant heat shielded section of a current lead member of the superconductive magnet comprises a high temperature oxide superconductor bulk body having a critical temperature exceeding a liquid nitrogen temperature. In this case, it is preferable to apply a resin impregnation treatment to the bulk body to enforce the high temperature oxide superconductor bulk body section.

Abstract: An aqueous solution of mixed metal acetate including one kind or more of element selected from lanthanide series and yttrium, barium and copper is mixed with trifluoroacetic acid to prepare a solution of mixed metal trifluoroacetate. From a solution of mixed metal trifluoroacetate obtained thus, purified mixed metal trifluoroacetate of which total content of water and acetic acid is 2% by weight or less is prepared. With purified mixed metal trifluoroacetate, an oxide superconductor of excellent performance may be prepared.

Abstract: The polycrystalline thin film is made of a composite oxide of a cubic crystal system which has a pyrochlore type crystalline structure of a composition represented as either AZrO or AHfO (A in the formula represents a rare earth element selected from among Y, Yb, Tm, Er, Ho, Dy, Eu, Gd, Sm, Nd, Pr, Ce and La) formed on the film forming surface of the polycrystalline substrate, wherein the grain boundary misalignment angle between the same crystal axes of different crystal grains in the polycrystalline thin film along a plane parallel to the film forming surface of the polycrystalline substrate are controlled within 30°.

Abstract: A method of fabricating a Josephson device includes the steps of forming a first superconducting layer and forming a second superconducting layer to form a Josephson junction therebetween, wherein the step of forming the second superconducting layer includes the steps of conducting a first step of forming the second superconducting layer with improved uniformity and conducting a second step of forming the second superconducting layer on the second superconducting layer formed in the first step with improved film quality.

Abstract: A superconducting laminated oxide substrate, which comprises a laminate a layer of a superconducting oxide crystal substrate made of a superconducting oxide single crystal or a superconducting oxide polycrystal and a layer of a reinforcing crystal substrate, prevents cracks from occurring in the superconducting oxide crystal substrate due to the heat treatment conducted for the purpose of forming an insulation film or a conductor film, and provides easy connectivity between electrodes and wiring formed on substrates located at upper and lower positions.

Abstract: The present invention provides a tape-form oxide superconductor having a high degree of c-axis alignment and in-plane alignment and an improved Jc value. On a tape-form metal substrate which is non-magnetic or weakly magnetic and has high strength, there are sequentially formed a first intermediate layer wherein YSZ or Zr2Rx2O7 particles are deposited from a target with ion irradiation from a direction inclined to the metal substrate, a second intermediate layer of CeO2 or Y2O3 is formed and an RE1+XBa2−XCu3OY superconducting layer is formed by coating metalorganic salts containing F, followed by thermal decomposition.

Abstract: A superconductor having at least one Hg—M—Cu—O (M=Ba, Sr and/or Ca) superconducting film provided on a substrate and having a thickness of between 300 Å to 950 Å. The superconductor may be prepared by forming, on a substrate, a precursor laminate composed of a first, M—Cu—O film and a second, Hg—O film. The precursor laminate film-bearing substrate is placed in a closed vacuum chamber together with a first pellet of HgO, MO and CuO and a second pellet of MO and CuO. The contents in the chamber are heated to form, on the substrate, a superconducting Hg—M—Cu—O film. The thickness of the first M—Cu—O film of the precursor is controlled so that the thickness of the superconducting Hg—M—Cu—O film is in the range of between 300 Å to 950 Å.

Abstract: An Hg- or Nd-based oxide superconductor comprises Ba as a constituent element and has a content of carbon as an impurity at a level of not greater than 2.0 atomic % whereby the oxide superconductor stably shows high superconducting characteristics without causing degradation with time. For its production, BaO, which has a reduced content of carbon impurity of 0.5% or below, is provided as a feed stock for Ba, and the starting materials are mixed and processed in a dry atmosphere wherein an amount of a carbon-containing gas is suppressed to a certain level, thereby obtaining the oxide superconductor.

Abstract: The invention provides a method for stably preparing a bismuth-based high temperature superconductor of a Bi-2223 single-phase or a Bi/Pb-2223 single phase, wherein a second phase is not allowed to reside, at a low cost and efficiently. With the method described above, mixed powders of raw materials (mixed powders of oxides and carbonates), obtained by mixing the raw materials such that a mixing ratio of constituents, Bi:Sr:Ca:Cu or (Bi, Pb):Sr:Ca:Cu, becomes identical to the stoichiometric ratio of a crystal of the superconductor Bi2Sr2Ca2Cu3Oz, or (Bi, Pb) 2Sr2Ca2Cu3Oz, respectively, are used as raw material for sintering, and the sintering is applied thereto, using KCl as a flux. In this case, the raw material for the sintering as calcinated is preferably used, and the sintering is preferably applied at a sintering temperature kept at a constant level.

Abstract: An aqueous solution of mixed metal acetate including one kind or more of element selected from lanthanide series and yttrium, barium and copper is mixed with trifluoroacetic acid to prepare a solution of mixed metal trifluoroacetate. From a solution of mixed metal trifluoroacetate obtained thus, purified mixed metal trifluoroacetate of which total content of water and acetic acid is 2% by weight or less is prepared. With purified mixed metal trifluoroacetate, an oxide superconductor of excellent performance may be prepared.

Abstract: An Hg- or Nd-based oxide superconductor comprises Ba as a constituent element and has a content of carbon as an impurity at a level of not greater than 2.0 atomic % whereby the oxide superconductor stably shows high superconducting characteristics without causing degradation with time. For its production, BaO, which has a reduced content of carbon impurity of 0.5% or below, is provided as a feed stock for Ba, and the starting materials are mixed and processed in a dry atmosphere wherein an amount of a carbon-containing gas is suppressed to a certain level, thereby obtaining the oxide superconductor.

Abstract: In order to provide an inexpensive mechanical persistent current switch with a short operation time and a large capacity without causing energy loss, a mechanical persistent current switch comprises a bulk member which is made of RE-Ba—Cu—O superconductor (RE is a rare earth element), connector material, and the bulk member made of RE-Ba—Cu—O superconductor is made by a melt process in which resin is impregnated, and an current terminal and a voltage terminal pasted onto the bulk member.

Abstract: A superconductor signal amplifier which receives an extremely small high-frequency signal having a frequency of tens of GHz generated in a superconductive circuit, amplifies the voltage of the high-frequency signal without a decrease in frequency, and outputs the thus amplified high-frequency signal from the superconductive circuit. At an output part of a single flux quantum circuit using a flux quantum as a binary information carrier, there are provided a superconductive junction line for flux quantum transmission and a splitter for simultaneously producing two flux quanta from a flux quantum. According to the number of plural series-connected SQUIDs, a plurality of flux quantum signals are generated and input to the plural series-connected SQUIDs so that the SQUIDs are simultaneously switched to a voltage state. In each SQUID pair comprising two SQUIDs, a part of an inductor is shared by the two SQUIDs for reduction in inductance, thereby increasing an output voltage of the series-connected SQUIDs.

Abstract: An oxide superconductor is capable of assuring a high trapped magnetic field and maintaining its performance for a long period of time without being affected by internal or external forces, such as thermal strain or by corrosive environments. The oxide superconductor contains a resin impregnated layer incorporated with a filler material having a low value of linear thermal expansion coefficient, or contains the resin impregnated layer or a resin impregnated layer incorporated with a filler material and covered with a resin layer incorporated with the filler material having a low value of linear thermal expansion coefficient, or contains an oxide superconductive bulk body having an adhesively covering layer of resin impregnated fabric on the outside surface, or contains an oxide superconductive bulk body having on the surface thereof a resin or a resin-impregnated layer dispersedly incorporated with a filler material.

Abstract: A superconducting power circuit comprises a bridge circuit, comprising superconducting switch elements having two or more Josephson junctions incorporated at each side of a rhombus-shaped bridge line, the superconducting switch elements being freely switchable by an outside magnetic field; and a control section which uses the outside magnetic field to switch one pair of the superconducting switch elements, arranged on opposite sides of the bridge circuit, to a superconductive state, and switch another pair of the superconducting switch elements to a normal-conductive state; the superconducting power circuit enables a large low-voltage dc current to be converted with high efficiency.

Abstract: An oxide superconducting element is formed on a substrate 10 by a layered structure 30 formed of oxide superconducting thin-film and a non-superconducting thin-film layers. The element is a superconducting regular current interval voltage step element. The current-voltage characteristic curve in a magnetic field has a voltage step being generated at regular bias current intervals. The layered structure 30 is formed by depositing alternately M′Ba2Cu3O7 (M′ is one or a combination of more than two elements of Nd, Sm and Eu) and M″Ba2Cu3O7 thin-films (M″ is either Pr or Sc, or a combination of the two elements).