Abstract: Superconductor precursor solutions are disclosed. The precursor solutions contain, for example, a salt of a rare earth metal, a salt of an alkaline earth metal and a salt of a transition metal. The precursor solutions can optionally include a Lewis base. The precursor solutions can be processed relatively quickly to provide a relatively thick and good quality intermediate of a rare earth metal-alkaline earth metal-transition metal oxide.

Abstract: The present invention provides a process for the preparation of high temperature superconducting (HTS) bulk current leads capable of supplying a continuous current of more than 200 A at 77 K, at least for 2 to 4 hours without any substantial heat load to cryogen free cryocooler and other superconducting magnet systems. The superconducting bulk current leads with improved properties are prepared from an improved high temperature superconducting (HTS) bismuth based cuperate [(Bi, Pb)2Sr2Ca2Cu3O10+x] material in tube and rod shape with both end metallic contacts.

Abstract: The present invention relates to a method of preparing an oxide superconducting film, the method includes reacting a metal acetate containing metal M selected from the group consisting of lanthanum, neodymium and samarium with fluorocarboxylic acid having not less than three carbon atoms, reacting barium acetate with fluorocarboxylic acid having two carbon atoms, reacting copper acetate with fluorocarboxylic acid having not less than two carbon atoms, respectively, followed by refining reaction products, dissolving the reaction products in methanol such that a molar ratio of the metal M, barium and copper is 1:2:3 to prepare a coating solution, and coating a substrate with the coating solution to form a gel film, followed by calcining and firing the gel film to prepare an oxide superconducting film.

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: A process for the preparation of nanostructured materials in high phase purities using cavitation is disclosed. The method comprises mixing a metal containing solution with a precipitating agent and passing the mixture into a cavitation chamber. The chamber consists of a first element to produce cavitation bubbles, and a second element that creates a pressure zone sufficient to collapse the bubbles. The process is useful for the preparation of mixed metal oxide catalysts and materials for piezoelectrics and superconductors.

Abstract: The new preparation process for making fine high specific surface ceramic powders suitable as catalysts or precursors for ceramics uses lanthanum (or other rare earth lanthanide) oxide as one of the precursors. The oxide is mixed with water to form a liquid slurry, whereby it is transformed to the hydroxide by reaction with water. The resulting hydroxide slurry, which can be milled to reduce the particle size and to speed up the reaction, is then combined, while stirring vigorously to assure homogenous mixing, with a solution of required amount of remaining metal nitrate precursors, for example strontium and cobalt nitrates. The reaction between lanthanum hydroxide and transition metal nitrates produces a colored (color depending on the transition metal) slurry consisting of metal hydroxides suspended in aqueous nitrate solution with pH>2. This perovskite precursor slurry is spray-frozen and freeze dried.

Abstract: A bulk high temperature superconductor single crystal having the formula MBa.sub.2 Cu.sub.3 O.sub.7-x wherein M is selected from the group consisting of Y, Sm, Eu, Gd, Dy, Ho, Er, and Yb; and, x has a number value from about 0.1 to about 1.0; are produced by a novel process incorporating: i) starting powders produced by combustion spray pyrolysis, ii) a novel setter powder, and/or iii) a monitored isothermal growth process.

Abstract: A description is given of superconducting substances having a content of Bi, Sr, Ca and Cu, and of processes for their preparation from the metal oxides within a range which is specified by the overall composition Bi.sub.a (Sr,Ca).sub.b -Cu.sub.6 O.sub.x, where a=3-24 and b=3.23-24, with an Sr/Ca atomic ratio of 1:9-9:1 and a Bi:(Ca+Sr) atomic ratio of 0.3-1.5. The transition temperature is at least 60 K. The principal phase crystallizes in the orthorhombic system. The pure compounds Bi.sub.4 (Sr,Ca).sub.4 Cu.sub.2 O.apprxeq..sub.12 and Bi.sub.4 (Sr,Ca).sub.6 Cu.sub.4 O.apprxeq..sub.20.

Abstract: A method of manufacturing an oxide superconductor, including the steps of mixing oxide materials of the metals contained in an oxide superconductor represented by HgBa.sub.2 Ca.sub.2 Cu.sub.3 O.sub.8+y to prepare a powder mixture of the composition noted above, molding the powder mixture to prepare a molded body of a desired shape, and applying a heat treatment to the molded body within a hermetic container at a temperature sufficient for bringing about a solid phase reaction of the oxide materials for at least 20 hours.

Abstract: In the production of a 124-type or 123-type superconductor by a sol-gel method using alkoxides of respective metals, the use of a compound wherein a secbutoxy group and a hydroxy group are coordinated with a copper atom gives a superconductor composed of flat particles having a broad C plane. The dimensional ratio defined by l/d is at least 6.7 in the case of the 124-type or is at least 8.4 in the case of the 123-type. It shows a superconducting property at a liquid nitrogen temperature. This superconductor shows a higher critical current density than one obtained by a sintering method.

Abstract: A method for synthesizing ultrahomogeneous nanoparticles of precursor powder by coprecipitation in a water and oil microemulsion is disclosed. The powder is compressed and sintered to prepare an essentially pure 2223 superconductor.

Abstract: To prepare a phase-pure, ceramic oxide superconductor which contains, in addition to copper, at least one alkaline earth metal from the group comprising Ba, Sr and Ca, and at least one metal from the group comprising Y, La, Tl, Pb and the rare earths, for example of YBa.sub.2 Cu.sub.3 O.sub.7-x, a solution is prepared which contains the metal components in the atomic ratios of the superconductor. The metals are precipitated as oxalates by combining this solution with an oxalic acid solution, the mixture of the oxalates is separated off, dried and decomposed to form the oxides, and the latter are subsequently sintered at temperatures of from 700.degree. to 900.degree. C. in the presence of oxygen to form the superconductor. In this process, the heating of the metal oxalates and the oxides formed therefrom up to 700.degree. C. is carried out at a maximum oxygen partial pressure of 50 mbar, preferably in an inert gas.

Abstract: A method of producing a compound oxide of elements including at least one of thallium, bismuth, lead, antimony, yttrium, each of rare earth elements, each of transition metal elements, each of alkali metal elements and each of alkaline earth metal elements. The method is comprised of the steps of (i) reacting at least one of carbonate, basic carbonate, hydroxide and co-precipitates of each of the above-mentioned elements with an amount of citric acid that is less than the weight equivalent of citric acid needed to form a completely citrated compound, and (ii) calcining the partly citrated compound. The co-precipitate can be one of a carbonate, a basic carbonate and a hydroxide of each of the above-mentioned elements.

Abstract: Process for preparing a high temperature superconductor such as yttrium bum copper oxides, by dissolving suitable proportions of hydrolyzable salts, oxides, or organometallic compounds of yttrium, barium and copper in an acid pH-controlled water-containing organic solvent such as methanol, and subjecting the resulting solution to ultrasonic energy or to an oxidation-reduction reaction, preferably while passing oxygen under a positive pressure through the solution, and precipitating a hydrolyzed precursor material. Such precursor material is then heated or annealed at temperatures between about 300.degree. C. and about 600.degree. C., also preferably in the presence of flowing oxygen, to produce the desired high temperature superconductor material.

Abstract: An improved process for preparing a superconducting composition having the formula M.sub.W A.sub.E Cu.sub.V O.sub.K wherein M is selected from the group consisting of Bi, Tl, Y, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm Yb and Lu; A is at least one alkaline earth metal selected from the group consisting of Ba, Ca and Sr; x is at least 6; w is at least 1; z is at least 2 and v is at least 1; said composition having a superconducting transition temperature of above 77K, preferably above about 90 K; said process consisting essentially of (a) forming a suspension having an M:A:Cu atomic ratio of w:z:v by mixing A(OH).sub.2, AO or AO.sub.2 and M.sub.2 O.sub.3 with an aqueous solution of cupric carboxylate or cupric nitrate at a temperature from about 50.degree. C. to about 100.degree. C., or mixing A(OH).sub.2 with an aqueous solution of Cu carboxylate, nitrate or a mixture thereof and M carboxylate, nitrate or a mixture thereof at a temperature from about 50.degree. C. to about 100.degree. C.