Abstract: This invention provides a production method of Nb3Al superconducting multifilamentary wire based on rapid-heating, quenching and transformation method, capable of producing a high-performance Nb3Al superconducting multifilamentary wire by improving critical temperature thereof, upper critical field and critical current density. Upon a first stage heat treatment of beating a composite, in which bcc phase Nb—Al supersaturated solid solution is dispersed in Nb matrix, the bcc phase Nb—Al supersaturated solid solution ordered in temperature rise process is made disordered at an initial phase thereof and a non-reacting portion located adjacent is heated using a reaction heat generated when transforming this disordered bcc phase to A15 phase. Then, disordering of the bcc phase is promoted while propagating a high-temperature transformation region so as to automatically progress high-temperature beat treatment.

Abstract: A high-performance Nb3Al extra-fine multifilamentary superconducting wire is produced simply and inexpensively through the improvement of critical values, Tc, Hc2 and Jc, without the addition of third elements such as Ge, Si and Cu. A first rapid heating and quenching treatment is applied to an Nb/Al composite wire having an atomic ratio of Al to Nb from 1:2.5 to 1:3.5 and having an extra-fine multifilamentary structure to form a BCC alloy phase comprising Nb with Al supersaturatedly dissolved therein wherein the treatment comprises heating the composite wire up to a temperature not lower than 1900° C. within two seconds and then introducing it into a molten metal at a temperature not higher than 400° C. to rapidly quench it.

Abstract: A method of producing an Nb—Sn compound superconducting wire precursor includes forming composite filament materials, each filament including a niobium material of an Nb-based metal and a titanium material of pure Ti enveloped in the niobium material; forming a composite rod in which composite filament materials are arranged in a matrix of a Cu-based metal but not in contact with one another, the matrix containing Sn diffused by heat treatment to combine with the niobium material to form a compound; and drawing the composite rod.

Abstract: A high Tc superconducting ceramic material is produced by a method in which a mixture of chemicals in suitable amounts is compacted into a desired form. The compacted mixture is then fired and, at the same time, an electric current is caused to pass through the compacted mixture in a predetermined direction. By virtue of the passage of the current through the material during firing, the orderliness of the molecular arrangement is enhanced and an elevated transition temperature Tc is obtained.

Abstract: A method of treating a part made of a superconductive ceramic of the (Ln).sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-.delta. type, where Ln is chosen from the rare earth elements other than cerium and terbium, the method being designed to reduce the value of .delta., in which method said part is heat treated in an oxidizing atmosphere, said method being wherein, during said treatment, an electric current with a density lying in the range 0.1 A/cm.sup.2 to 2 A/cm.sup.2 is caused to flow through said part, said treatment atmosphere having a partial pressure of oxygen lying in the range 0.1 atmospheres to 1 atmosphere, the treatment temperature lying in the range 200.degree. C. to 500.degree. C., and the duration of said treatment lying in the range 1 hour to 200 hours.

Abstract: A method of manufacturing an Nb.sub.3 Al superconducting wire includes a step of forming a wire by a jelly-roll process, a first thermal step of heating the obtained wire at a temperature of 500.degree. to 700.degree. C. for at least 10 hours for diffusing Al in Nb while suppressing formation of Nb.sub.3 Al, and a second thermal step of heating the wire, after the first thermal step, at a temperature of 800.degree. to 1050.degree. C. for about 0.01 to 10 hours, thereby forming Nb.sub.3 Al. In the jelly-roll process, a sheet of Nb and a sheet of Al are lap-wound on a copper core. The material obtained by such lap winding is inserted in a copper pipe, and then subjected to drawing. The drawn wire is cut to obtain a plurality of segments. The plurality of segments are bundled and charged in a copper pipe, and then subjected to drawing. The resulting drawn wire is subjected to the first and second thermal steps.

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: A superconductive fullerene and a process for making such superconductive fullerene are provided. The process involves contacting-a quantity of fullerene with the vapor of an interhalogen compound such as ICl. The halogen doped fullerenes exhibited a transition temperature above 60 K.

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 organic superconductive material and a process for producing the same are disclosed, the material comprising a polymer having dispersed therein an organic superconductive substance comprising an electron donor and an electron acceptor.

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: A method for making a superconducting fullerine composition, includes reacting a fullerine with an alloy, and particularly reacting C.sub.60 with a binary alloy including an alkali metal or a tertiary alloy including two alkali metals in the vapor phase. Also, a Cesium-doped fullerine high T.sub.c superconducting composition has the formula Cs.sub.x C.sub.60, and particularly Cs.sub.3 C.sub.60. Also, a homogeneous bulk single phase high T.sub.c superconducting composition has the formula (Rb.sub.x K.sub.1-x).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: A superconducting oxide precursor material is prepared by dissolving soluble compounds containing the non-oxygen elements of the oxide in concentrated nitric acid, in which a decomposing agent for the nitrate of the nitric acid selected from urea and sucrose and an oxidizing/reducing agent selected from hydrogen peroxide and ammonium nitrate have also been dissolved. The acid solution is concentrated by heating until the liquid component is pyrolyzed, leaving a superconducting oxide precursor material residue. The precursor material is produced with a relatively high oxidation state, but is normally further oxidized to reach a superconducting state.

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: 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.

Abstract: A process for producing an organic electrical conductor comprising the steps of: (1) dissolving or dispersing an electron-donating material and an electron-accepting material in a solvent containing an alcohol; and (2) forming and growing crystals of the organic electrical conductor by subjecting the dissolved or dispersed materials of step (1) to electrochemical oxidation-reduction.

Abstract: In one embodiment this invention provides a process for decreasing the resistivity of an electrical conductor.The process involves the application of high temperature and an external field to a conductor to induce a current flow and physicochemical transition in the conducting matrix.

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 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.

Abstract: Metal oxide superconductors of the yttrium-barium-copper type can be formed by precipitation from an aqueous solution of the salts of the metals using an oxalate precipitation reagent under basic pH conditions to form a fireable precursor only partly in the form of the oxalate salts of these metals.

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: A method of producing a superconducting circuit by forming a film having a superconducting phase on a substrate and applying a laser beam to a part of the superconducting phase to cause transition of the part of the superconducting phase into a non-superconducting phase.

Abstract: The invention relates to an improvement in a method of forming deposits of superconducting ceramics. Generally, such ceramics are formed by electrodepositing a mixture of metals of the type, and in proportions sufficient to be oxidized into ceramic, onto a substrate. The electrodeposited mixture is then oxidized under conditions sufficient to result in a super conducting ceramic deposit. The improvement resides in conducting the electrodeposition in a manner which results in a patterned electrodeposition prior to conducting oxidation.

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: 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: Copper alkoxy alkoxides of the formula CuOR or Cu(OR).sub.2, where R is derived from an alkoxy alkanol of from 3 to 8 carbon atoms, are superconducting ceramic precursors. Compositions containing these alkoxides solubilized in an organic solvent, such as toluene, can be prepared by the additional use of a barium alkoxide solubilization agent.

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.

Abstract: Metal oxide superconductors of the yttrium-barium-copper type (YBa.sub.2 Cu.sub.3 O.sub.4 type) can be formed by precipitation from an aqueous solution of the salts of the metals using an oxalate precipitation reagent under basic pH conditions (e.g., at least 11) to form a fireable precursor only partly in the form of the oxalate salts of these metals.