Abstract: Disclosed is a superconducting compound which has a structure obtained by partially substituting oxygen ions of a compound, which is represented by the following chemical formula; LnTMOPh [wherein Ln represents at least one element selected from Y and rare earth metal elements (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu), TM represents at least one element selected from transition metal elements (Fe, Ru, Os, Ni, Pd and Pt), and Pn represents at least one element selected from pnictide elements (N, P, As and Sb)] and has a ZrCuSiAs-type crystal structure (space group P4/nmm), with at least one kind of monovalent anion (F?, Cl? or Br?). The superconducting compound alternatively has a structure obtained by partially substituting Ln ions of the compound with at least one kind of tetravalent metal ion (Ti4+, Zr4+, Hf4+, C4+, Si4+, Ge4+, Sn4+ or Pb4+) or a structure obtained by partially substituting Ln ions of the compound with at least one kind of divalent metal ion (Mg2+, Ca2+, Sr2+ or Ba2+).

Abstract: A new boron-carbon system superconductive substance has a nominal composition expressed R.sub.3 M.sub.4-x B.sub.4-y C.sub.3-z (where R is at least one element selected from the group consisting of Y, Sc and lanthanide series elements, M is at least one metal element categorized in VIII group of periodic table, and 0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1, 0.ltoreq.z<3, except a case of x=y=1 and z=0).

Abstract: A process for preparing a copper oxide superconductor of (Ba,Sr)-Cu-C-O containing carbonate radicals is disclosed, which comprises the steps of: mixing alkaline earth metal compounds and a copper compound with a molar ratio of 1.1 to 2.25 to obtain a mixture; pressing said mixture to form a pellet; and sintering said pellet in an oxygen atmosphere, wherein the alkaline earth metal compounds including a barium compound selected from the group consisting of barium carbonate and barium oxalate, and a strontium compound selected from the group consisting of strontium carbonate and strontium oxalate and the copper compound selected from the group consisting of copper carbonate, copper nitrate, copper oxalate and copper oxide.

Abstract: Superconducting, metal-doped fullerenes are provided, along with processes for their preparation in relatively high stoichiometric purity. In one embodiment, the processes provide fullerenes of the formula M.sub.x C.sub.q, where M is a metal, x is greater than 0 but less than about 10, and q is at least 60. The processes comprise contacting C.sub.q with metal in an amount and under reaction conditions effective to produce a compound having the formula M.sub.y C.sub.q, and contacting said M.sub.y C.sub.q with a portion of C.sub.q in an amount and under reaction conditions effective to produce said M.sub.x C.sub.q, wherein y is greater than x.

Abstract: The present invention relates to a new process for making metal fulleride compositions having the formula A.sub.n (C.sub.x).sub.m, wherein A is a metal cation and C.sub.x is a fullerene anion, preferably C.sub.x is C.sub.60 or C.sub.70, wherein n is a number equal to the absolute value of the valence of the fullerene anion, wherein m is equal to the absolute value of the valence of A, wherein the values of n and m are divided by their greatest common factor, if any, and wherein the metal fulleride composition is neutral in charge. This process comprises reacting a metal with a fullerene in a solvent or mixture of solvents in which the fullerene is at least partly soluble at a temperature from greater than the freezing point to equal to or less than the boiling point of the solvent, for a time sufficient to form the metal fulleride composition.

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: Superconducting, metal-doped fullerenes are provided, along with processes for their preparation in relatively high stoichiometric purity. In one embodiment, the processes provide fullerenes of the formula M.sub.3 C.sub.60 where M is an alkali metal. The processes comprise contacting C.sub.60 with alkali metal in an amount and under reaction conditions effective to produce a compound having the formula M.sub.y C.sub.60, where y is greater than 3, and contacting said M.sub.y C.sub.60 with a portion of C.sub.60 in an amount and under reaction conditions effective to produce said M.sub.3 C.sub.60.

Abstract: Process for preparing NbN superconducting material, characterized in that a bulk Nb is placed in powder including at least one metal which can be nitriding-burned, and then the powder is heated to be nitriding-burned in pressurized N.sub.2 atmosphere so that the bulk Nb is nitrided by the nitriding-burning of the powder.

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 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: Processes are described for electroplating metal or alloy on superconducting oxides using either a nonaqueous bath or aqueous bath with suitably applied potential. Articles made in accordance with the electroplating process are also described.

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: 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.