Abstract: High-Tc superconducting ceramic oxide products and macroscopic and microscopic methods for making such high-Tc superconducting products. Completely sealed high-Tc superconducting ceramic oxide provides are made by a macroscopic process including the steps of pressing a superconducting ceramic oxide powder into a hollow body of a material inert to oxygen; heat treating the superconducting ceramic oxide powder packed body under conditions sufficient to sinter the ceramic oxide powder; and then sealing any openings of the body. Optionally, a waveform or multiple pulses of alternate magnetic filed can be applied during the heat treatment.

Abstract: The present invention concerns an enhancement of the supercurrent carrying capabilities of bicrystalline or polycrystalline high-Tc superconductors, i.e. the critical current densities in such superconductors. The current transport properties are improved by chemically altering, especially doping, the superconductors. It seems that a modification of the space-charge layers at the boundary, e.g. by an increase of the mobile charge carrier concentrations particularly in the superconductor's grain boundaries, which concentrations differ from those resulting in optimum superconducting properties of the grains, are responsible for this positive effect.

Abstract: A reduced coefficient of friction, preferably created by ideal lubrication conditions, may advantageously be employed in the breakdown deformation of a precursor to a multifilamentary superconducting composite, particularly in combination with one or more high reduction breakdown drafts, to improve composite homogeneity and significantly increase the range of deformation conditions over which dimensional tolerances and Je may be optimized. Precursor composites made by this method exhibit reduced microhardness variability and fewer and less serious transverse filament defects than composites made by prior art methods. The method comprises the steps of: first, providing a precursor article comprising a metal matrix surrounding a plurality of filaments extending along the length of the article and comprising precursors to a desired superconducting ceramic; next, roll working the precursor article during a breakdown stage at a predetermined pressure and a coefficient of friction less than about 0.

Abstract: The invention relates a powder in tube type method of making an HTc superconductive multifilament strand having a silver-based matrix, in which:

Abstract: Circuit board devices are provided based on use of high temperature superconducting ceramic polymers comprising high temperature superconducting ceramic powders distributed in electrically insulative organic polymers which are thermosetting by reaction of a two-part liquid mixture or by catalytic or photoinitiation of a one-part liquid. The ceramic domains transmit their superconductivity across the insulating barriers of organic polymers enabling formation of superconductive lines and superconducting bonds to electronic devices to be adhered to circuit boards, and providing superconducting circuitry.

Abstract: An oxide superconductor comprises a composition represented by the composition formula: (Nd.sub.x --Ce.sub.y --L.sub.z).sub.2 CuO.sub.4-d (wherein L is an element selected from Ca and Mg, and x+y+z=1). The compositions of Nd, Ce and L of the oxide superconductor corresponds to a point falling inside an area of Nd--Ce--L ternary diagram surrounded by straight lines (A-B), (B-C), (C-D) and (D-A) connecting point (A) with point (B), point (B) with point (C), point (C) with point (D) and point (D) with point (A), respectively, the points (A), (B), (C) and (D) being points (x=1, y=0, z=0), (x=0.4, y=0.6, z=0), (x=0.4, y=0.3, z=0.3) and (x=0.1, y=0, z=0.9), respectively, in the Nd--Ce--L ternary diagram. Above-described Nd--Ce--L--Cu--O oxides can exhibit superconductivity within a wide range of composition when heat-treated in an atmosphere of nitrogen.

Abstract: A method for production of a ceramic sheet includes the following steps: First, a pair of green sheets are prepared from ceramic material by the doctor-blade method. Each of the green sheets has first and second surfaces. The prepared sheets are placed one on the other and adhered to each other in such a manner that the first surfaces of the green sheets oppose each other. Alternatively, the second surfaces of the sheets may oppose each other. As a result, a united green sheet is obtained. A separating sheet is disposed on a side of the united green sheet. The united green sheet is rolled, with the separating sheet, around a core. The united green sheet, with the separating sheet, is sintered in a rolled configuration thereby producing a rolled ceramic sheet.

Abstract: The disclosed substance has a composition of Y.sub.x Ba.sub.y CuO.sub.z, wherein x=0.2-0.5 y=0.2-0.5 and z.perspectiveto.1+y+(3/2)x, with a face-centered tetragonal crystalline structure of perovskite type. When being cooled at 85-135 K, the structure of the substance starts to transform and its electric resistance disappears at a temperature higher than 47 K so that the substance becomes superconductive.

Abstract: A glass-ceramic superconductor is disclosed, having a nominal stoichiometric composition consisting essentially of the oxides of Bi, Ca, Sr, Cu and Zn in the stoichiometric formula range: Bi.sub.2 Ca.sub.x Sr.sub.z Zn.sub.n Cu.sub.w O.sub.y, wherein x ranges about 1-2, z ranges about 1-2, n ranges about 0.001-2, w ranges about 1-2, and y ranges about 6-11. These compositions exhibit greatly improved glass stability, yet can yield highly crystalline superconductors which may include large platelet crystals and which can exhibit very low room temperature resistivity.

Abstract: A pipe comprises a hollow support member made from a member selected from copper and copper compounds and a copper oxide superconducting ceramic material which covers the inner surface of the support member with a space kept in the pipe for use in a magnet or power accumulator device.

Abstract: The invention relates to the preparation of high purity, chloride- and alkali metal-free copper (II) alkoxides by means of the reaction of an alcoholic alkali metal alkoxide solution with copper (II) fluoride; ammoniating the resulting solution to render soluble the resulting copper (II) alkoxide; and filtering the resulting solution to obtain an alkali metal- and chloride-free alcoholic copper (II) alkoxide solution. The resulting solution is useful in the preparation of superconducting compound such as yttrium-barium-copper oxide superconductor.

Abstract: A superconductor is produced by electric discharge explosion flame spraying of a composite body of constituents of an immiscible alloy. The electrically discharged composite body is deposited on a substrate and the resultant alloy is oxidized to yield an oxide of the alloy having superconductive property. This process can be applied to the Ln-Ba-Cu system (Ln is at least one of the rare earth elements including Y), typically the Y.sub.1 Ba.sub.2 Cu.sub.3 - or Y.sub.2 Ba.sub.4 Cu.sub.8 system, or other immiscible alloy systems such as the Bi-(Ca, Sr)-Cu system to form an oxide thereof.

Abstract: A superconductive body of an oxidic superconductive material having good mechanical properties is characterized in that the oxidic material forms a matrix through which finely divided particles are mixed at least the surface of which consists of a metal or a metal alloy. Particles in the form of fibres are preferably used and the surface of the particles consists of silver or gold.

Abstract: A new class of Bi-based superconductive oxides is disclosed. As do the previously known Bi-based superconductors, the novel materials have a perovskite-like crystal structure. However, in contradistinction to the prior art materials, the inventive materials have unmixed B-site occupany, with all substituents occupying A-sites. This tends to produce marginal stability and enhanced transition temperatures, as compared to the prior art Bi-based oxide superconductors. Materials according to the invention have composition ABiO.sub.3-.delta., with A being Ba and at least one monovalent element (typically chosen from Na, K,Rb, and Cs) and 0.ltoreq..delta..ltorsim.0.1, and have a transition temperature T.sub.c.sup.onset .gtorsim.13K. The superconductive materials are advantageously produced from precursor material that contains an excess of the monovalent element(s), as compared to the final composition.

Abstract: Superconducting compositions of the general formula A.sub.n Q.sub.m Cu.sub.3 O.sub.y are prepared by wet mixing a combination organic acid salts, inorganic acid salts and oxides of A, Q and Cu, wherein at least one salt is an organic acid salt, drying the mixed salts, and then heating the resultant mixed salts to a temperature between 500.degree. and 950.degree. C. The temperature is maintained for a time sufficient to form a substantially orthorhombic superconducting composition. The method achieves good results with only one heating step. The presence of at least one organic salt causes carbonate and nitrate salts of A, Q and Cu to convert to oxides at temperatures between 300.degree. and 400.degree. C. With lower processing temperatures, semiconductor materials and superconducting materials can be processed together.

Abstract: There is disclosed an improved process for preparing a superconducting composition having the formula MBa.sub.2 Cu.sub.3 O.sub.x wherein M is selected from the group consisting of Y, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb and Lu; x is from about 6.5 to about 7.0; said composition having a superconducting transition temperature of about 90 K; said process consisting essentially of heating a precursor powder in an oxygen-containing atmosphere at a temperature from about 875.degree. C. to about 950.degree. C. for a time sufficient to form MBa.sub.2 Cu.sub.3 O.sub.y, where y is from about 6.0 to about 6.4; and maintaining the MBa.sub.2 Cu.sub.3 O.sub.y in an oxygen-containing atmosphere while cooling for a time sufficient to obtain the desired product; said precursor powder being prepared by (a) forming an aqueous solution of M(NO.sub.3).sub.3, Ba(NO.sub.3).sub.2 and Cu(NO.sub.3).sub.

Abstract: Novel superconductive Pb-substituted oxides are disclosed. The oxides all have layered perovskite-like crystal structure, and manifest superconductivity (R=o) above about 77K. The materials are described by the nominal formula X.sub.2+x M.sub.3-x Cu.sub.2 O.sub.8.+-..delta., where X is Bi and Pb, M is Sr and Ca, 0.ltoreq..times..ltoreq.0.3, 0.ltoreq..delta..ltoreq.0.5, the Pb/Bi ratio is between about 0.2 and about 0.5, and the Sr/Ca ratio is between 0.5 and 2.

Abstract: The present invention is directed to a method of producing metal oxides which are useful as high temperature superconductors. The method comprises the steps of:(a) mixing generally stoichiometric amounts of metal compounds with an alkali metal metal hydroxide, thereby forming a mixture;(b) heating the mixture to drive off water; and(c) filtering the mixture to remove the alkali metal ions.

Abstract: An aqueous solution of the monocarboxylates of Y, Ba, and Cu is spray dried, providing a contaminant-free non-hygroscopic product which is homogeneous at the atomic level. In a preferred embodiment Y, Ba, and Cu acetates are used in a molecular ratio of 1:2:3, giving a product which can be calcined to give a superconducting mixed oxide, YBa.sub.2 Cu.sub.3 O.sub.x, where x is 6.8-7.0.

Abstract: There is disclosed an improved process for preparing a superconducting composition having the formula MBa.sub.2 Cu.sub.3 O.sub.x wherein M is selected from the group consisiting of Y, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb and Lu; x is from about 6.5 to about 7.0; said composition having a superconducting transition temperature of about 90 K.; said process consisiting essentially of mixing ba(NO.sub.3).sub.2, M.sub.2 O.sub.3 and CuO in an atomic ratio of M:Ba:Cu of about 1:2:3 to form a precursor powder and heating the precursor powder in an oxygen-containing atmoshpere at a temperature from about 875.degree. C. to about 950.degree. C. for a time sufficient to form MBa.sub.2 Cu.sub.3 O.sub.y, where y is from about 6.0 to about 6.4; and maintaining the Mba.sub.2 Cu.sub.3 O.sub.y in an oxygen-containing atmosphere while cooling for a time sufficient to obtain the desired product.

Abstract: Superior homogeneity in ceramic materials is achieved by forming an aqueous solution of trichloroacetates of certain metals, heating the solution to decompose the trichloroacetates to form carbonate precipitates, and recovering the carbonate precipitates. The latter can be calcined to form superconductors. For example, oxides, or carbonates of Y, Ba, and Cu are dissolved in aqueous trichloroacetic acid and the solution is heated to decompose trichloroacetate ions and to form mixed carbonates, which precipitate. The precipitate is recovered and calcined to form a superconducting material.

Abstract: A class of melt-produced, high temperature suerpconductors and processes of making same are provided. The superconductor has a preferred composition of R-Ba-Cu-O wherein R is chosen from the group of rare earth metals excluding: Praseodyium; Cerium; and Terbium. The process is carried out at a relatively low temperature of about 950.degree. C., and the process allows fabrication of melt-produced high temperature superconductors of arbitrary shape. The process is based on the reaction between molten barium-copper oxides and solid rare earth oxides, rare earth barium oxides, rare earth copper oxides, or rare earth barium-copper oxides. In an embodiment, the method comprises the steps of: mixing and grinding BaCO.sub.3 and CuO with other nominal compositions; pressing the resultant mixture into a pellet, if necessary; placing the pellet or powder on a pellet or powder that can include rare earth copper oxides; heating the pellet and/or powders to a temperature of approximately 950.degree. C.

Abstract: A ceramic type superconductive layer (2) is formed on the outer peripheral surface of an optical fiber (1), and a stabilizing layer (3) is formed so that it contacts the outer peripheral surface of the superconductive layer (3). The diameter of the optical fiber is, for example, not more tha 100 .mu.m. The superconductive layer may be formed with a spirally extending groove (7) which divides the superconductive layer.

Abstract: Method and apparatus for preparing highly pure homogeneous precursor powder mixtures for metal oxide superconductive ceramics. The mixes are prepared by instantaneous precipitation from stoichiometric solutions of metal salts such as nitrates at controlled pH's within the 9 to 12 range, by addition of solutions of non-complexing pyrolyzable cations, such as alkyammonium and carbonate ions.

Abstract: Compositions containing a phase having the formula LA.sub.2-x Na.sub.x CuOz wherein x is about 0.1 to about 0.3 and z is about 3.8 to about 4.2 are superconducting. Processes for manufacturing such compositions and for using them are disclosed.