Abstract: The disclosed method can produce high T.sub.c superconductor material e.g., YBa.sub.2 Cu.sub.3 O.sub.7) of substantially increased intra-grain critical current density (J'.sub.c), as compared to conventionally produced bulk material of analogous composition. Exemplarily, YBa.sub.2 Cu.sub.3 O.sub.7 pellets produced according to the invention had J'.sub.c of about 10.sup.5 A/cm.sup.2 at 77 K. in an applied magnetic field of 0.9 Telsa. The inventive method comprises providing a precursor material whose composition differs from that of the desired superconductor with respect to at least one of the metal constituents of the desired superconductor. It further comprises heating the precursor material above the decomposition temperature (T.sub.d) of the precursor material such that a multiphase material results. The multiphase material comprises, in addition to a majority first phase, a dispersed precipitate phase. The method further comprises cooling the multiphase material to a temperature below T.sub.

Abstract: An oxide superconductor having the following formula:Pb.sub.2 Sr.sub.2 Ca.sub.1-p Ln.sub.p Cu.sub.3 O.sub.q orPb.sub.1-x Cu.sub.x Sr.sub.2 Ca.sub.1-y Ln.sub.y Cu.sub.2 O.sub.zwherein Ln represents a rare earth element, p is 0.3-0.7, q is 7.8-8.2, x is 0.2-0.5, y is 0.3-0.7 and z is 6.8-7.2 is prepared using a coprecipitation method. An acetic acid solution of carbonates, acetates or nitrates of Pb, Sr, Ca, Cu and Ln is mixed with an aqueous solution of oxalic or tartaric acid, or a lower alkyl ester thereof. The mixture is reacted to precipitate the Pb, Sr, Ca, Cu and Ln as oxalates or tartarates and the precipitates are dried and sintered to obtain the oxide superconductor.

Abstract: Superconducting microcircuits including a thin layer of Ba.sub.2 Cu.sub.3 O.sub.5+x (0<x<1) on a substrate. A thin layer of a dopant; for example, Y.sub.2 O.sub.3 for superconducting patterns of YBa.sub.2 Cu.sub.3 O.sub.7-x, or Pr.sub.2 O.sub.3 for insulator patterns of PrBa.sub.2 Cu.sub.3 O.sub.7-x. These layers are covered with a layer of photoresist, which is exposed to light through a mask having a pattern for a desired circuit. The photoresist is then developed to reveal a pattern of the thin dopant layer which will be etched away. The microcircuit is then etched and stripped to remove the unneeded portion of the thin dopant layer. Finally, the microcircuit is heated at a temperature and for a period of time sufficient to diffuse and react the dopant layer with the thin layer of Ba.sub.2 Cu.sub.3 O.sub.5+x, forming a pattern of superconductor or insulator.

Abstract: An yttrium-barium-copper oxide powder consisting of a powdery mixture of Y.sub.2 BaCuO.sub.5 with Ba.sub.3 Cu.sub.5 O.sub.8, which can be formed into a dense sintered body having excellent superconducting characteristics. An yttrium-barium-copper oxide superconducting body is manufactured by firing the above powder preferably at 820.degree.-980.degree. C. under oxidizing atmosphere having an oxygen partial pressure of 0.01-0.5 atm.

Abstract: This invention is directed to a method for making multiphase copper oxide based materials which have a phase having a zero resistance transition temperature above about 200K. The method comprises subjecting a copper oxide based material precursor to an oxygenation in an atmosphere comprising more than about 20% oxygen by volume at a temperature less than about 200.degree. C. for a time sufficient to form the material. The invention also is directed to maintaining the properties of a copper oxide based material having a zero resistance transition temperature above 150K.

Abstract: A process for preparing 123 superconductor material comprising heating a 123 compact in direct physical contact with a 211 compact to decompose only the 123 compact to form a liquid phase in the 123 compact is disclosed. The heat is maintained with the liquid phase passing into the 211 compact, to form a decomposed compact and an enriched compact. The decomposed and enriched compacts are cooled to below 1000 degrees celsius to promote a peritectic reaction between the 211 grains and the infiltrated liquid phase in the 211 compact. The decomposed and enriched compacts are then further cooled to about 400-600 degrees celsius in an oxygen atmosphere, and finally cooled to room temperature to yield a fused 123 decomposed compact-123 enriched compact. The 123 superconductor having enhanced electrical and mechanical properties is the 123 enriched compact which can be separated from the decomposed compact, by severing the 123 decomposed compact from the 123 enriched compact.

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: Disclosed is a process for the preparation of multi-element metal oxide, high temperature superconductor precursor powder comprising spraying a homogenous solution of a multi-element metal salt solution mixed in a stoichiometric ratio corresponding to the desired superconducting composition into a horizontal tube-like furnace being heated to a temperature of 800.degree.-1000.degree. C., transporting resulting sprayed mist along the main axis of the furnace tube by the aid of hot air and collecting resultant finely divided metal oxide powder by the aid of a filter, whereby the resultant mixed metal oxide powder is a precursor for the preparation of a high temperature superconducting ceramic.

Abstract: Disclosed is a method of improving the physical properties of superconducting materials which comprises:a. applying a high strain rate deformation to said materiThe United States Government has rights in this invention pursuant to Contract No. W-7405-ENG-48 between the U.S. Department of Energy and the University of California, for the operation of Lawrence Livermore National Laboratory.

Abstract: An oriented superconducting material may be made by cold pressing a nonoriented superconducting material selected from the group consisting of Bi.sub.1, Bi.sub.2, Tl.sub.1, Tl.sub.2, Pb substituted Bi.sub.1, Pb substituted Bi.sub.2, Pb substituted Tl.sub.1, and Pb substituted Tl.sub.2 superconductor materials at a pressure sufficient to form an oriented superconducting material.

Abstract: A method for manufacturing a pipe from a superconducting ceramic material is disclosed, which comprises providing a hollow supporting metallic body having a hollow inside section therein, introducing into the hollow inside section of the hollow supporting body a liquid into which is mixed a superconducting ceramic powder material comprising an oxidized copper material, drying the above liquid, so that the superconducting ceramic material is coated on the inside of the supporting body with a hollow space kept therein; and firing the supporting body and the ceramic material in an oxidizing atmosphere.

Abstract: The present invention provides a process for producing a superconducting material capable of elevating the Tc of oxide superconductors, in particular Bi-based superconductors. The feature of the present invention resides in a process for producing an oxide superconductor, in which a intermediate product or a product showing superconducting property is treated with a solution containing a compound having a reducing or oxidizing function. As the compound having a reducing function, compounds having two or more enolic hydroxy groups, cycloaliphatic polyhydric alcohol compounds or inorganic type reducing compounds are preferred. As the compound having oxidizing function, there can be mentioned, for example, carbonyl compounds, ozone, hydrogen peroxide, organic peroxide, dimethylsulfoxide and permanganate.

Abstract: The present invention comprises novel oxide materials exhibiting bulk superconductivity up to and exceeding 85K and processes for their synthesis. The oxides are within the formula R.sub.a Ba.sub.b Cu.sub.c O.sub.d wherein 1.9<a<2.1, 3.9<b<4.1, 6.8<c<7.2, 14.4<d<15.2 and wherein R is Y or any of the lanthanide rare earth elements. Certain substitutions such as Ca and La on the R and Ba sites are included.

Abstract: A superconductive oxide powder is produced by a method comprising spray drying a slip to form agglomerates, feeding the agglomerates sequentially through a first and a second oxygen supported combustion flame for fusing the fine particles in the agglomerates to form an intermediate powder, annealing the intermediate powder in an oxygen-containing environment such as to produce a friable mass, and crushing the mass to form the superconductive oxide powder. For example, a precursor compound in the slip is barrium carbonate, the other precursor constituents are yttrium oxide and copper oxide, and the yttrium, barium and copper in atomic proportions in the precursor constituents are 1:2:3+Y where Y denotes a copper surplus having a value of up to about 1.5. In the final powder the proportions are 1:2:3+Z where Z is between about 0.2 and 1.0.

Abstract: A molded article of ceramic oxide superconductor having an increased critical current density is produced by a method including sintering a powdery mixture of oxides and/or carbonates of elements which constitute the ceramic oxide superconductor to obtain a molded article, or melting the sintered ceramic oxide superconductor and molding the superconductor melt to obtain a molded article, wherein the powdery mixture and/or the molded article is irradiated.

Abstract: An in situ formed superconducting cermet comprising an interwoven matrix of a superconducting ceramic and a noble metal and a method of making same are disclosed.

Abstract: Ceramic superconductor materials, e.g., of rare earth/alkaline earth metal/transition metal/oxygen type, contain an effective stabilizing amount of fluorine atoms distributed therein in a concentration gradient decreasing from the external face surface of the material to the core region thereof; advantageously the fluorine atoms are principally distributed in an external protective diffusion barrier layer.

Abstract: The present invention relates to a superconducting material that is, substances having compositions expressed by empirical formulae Y.sub.1-x Ba.sub.x CuO.sub.3, YBa.sub.2 Cu.sub.3 O.sub.7 and LnBa.sub.2 Cu.sub.3 O.sub.7 and critical temperatures of 90 K. or more, and to a method of producing the same in which for example Y.sub.2 O.sub.3, BaCO.sub.3 and CuO are blended at a mixture molar ratio of 1:2:6 and the resulting mixture is molded under pressure followed by slowly cooling in an oxidizing atmosphere.

Abstract: The present invention relates to an improved process to produce an essentially carbon-free nitrate of an alkali metal, alkaline earth metal, transition metal, lanthanide metal, actinide metal, metal, or mixtures thereof, which process comprises:Contacting an anhydrous composition of an alkali metal, alkaline earth metal, transition metal, lanthanide metal, actinide metal, or mixtures thereof substituted with an organic or an inorganic carbon-containing substitute with flowing nitrogen dioxide, dinitrogen tetroxide or mixtures thereof at a temperature of between about 40.degree. to 150.degree. C. under anhydrous conditions for a time and at a pressure effective to form the nitrate of the alkaline metal, alkaline earth metal, transition metal, lanthanide metal, actinide metal, or mixtures thereof, essentially free of any carbon containing contaminant. Materials produced by this improved process are useful as electrical superconductors, e.g. YBa.sub.2 Cu.sub.3 O.sub.

Abstract: High T.sub.c superconducting compounds are made by forming a reaction mixture of the oxides of Sr, Cu, Ca and Tl, compressing these into a hardened body, and placing the hardened body into a container. The container is then evacuated and sealed. The hardened body is heated under pressure until the oxides of Sr, Ca, Cu, and Tl react to form a superconducting compound.

Abstract: The invention relates to a process for making a superconducting connection between a pair of superconducting ceramic oxide pieces, each of the pieces having been formed by combining the metallic elements of the superconducting oxide in substantially the stoichiometric proportions needed to form the superconducting oxide into a precursor and forming the precursor into a shaped piece. The process comprises the steps of: contacting each of the shaped pieces with the other; connecting each of the shaped pieces to the other by means for forming a metallurgical bond between the shaped pieces; and oxidizing the connected shaped pieces under conditions sufficient to oxidize the metallic elements to the superconducting oxide.In other embodiments of the invention, the process is for forming a superconducting connection between a pair of pieces having a superconducting ceramic oxide/noble metal composition; or for forming a joint between a superconducting ceramic oxide and a normal conductor.

Abstract: Disclosed is a method of manufacturing an oxide superconductor containing at least an alkaline earth metal and copper. This method comprises the steps of heating a material substance containing elements constituting the oxide superconductor, in an atmosphere having an oxygen partial pressure of at most 50 Torr at a temperature ranging from 500.degree. C. to 1000.degree. C., and then heating the material substance in an oxygen-containing atmosphere. Also disclosed herein is a method of manufacturing composite oxide powder which is the precursor of the oxide superconductor. This method comprises the steps of heating the material substance in an atmosphere having an oxygen partial pressure of at most 50 Torr at a temperature ranging from 500.degree. C. to 1000.degree. C., and crushing the material substance into powder.

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 process for controlling an oxygen content of a non-superconductive or superconductive oxide is provided, in which a beam of particles such as ions, electrons or neutrons or an electromagnetic radiation is applied to the non-superconductive or superconductive oxide of a perovskite type such as YBa.sub.2 Cu.sub.3 O.sub.7-x, thereby increasing or reducing the oxygen content of the oxide at the sites of oxygen in the crystal lattice of the oxide. Furthermore, a superconductive device such as a superconductive magnet, superconductive power transmission wire, superconductive transformer, superconductive shield, permanent current switch and electronic element is made by utilizing the process for controlling the oxygen concentration of the superconductive oxide.

Abstract: A process for silver coating superconducting ceramic powder by(1) mixing AgNO.sub.3 with the superconducting ceramic powder particles;(2) melting the AgNO.sub.3 so that it wets and forms a uniform coating over he surfaces of the particles; and(3) decomposing the AgNO.sub.3 to form a thin, uniform coating of silver metal on the surfaces of the particles.The product is a loose powder of superconducting ceramic particles which are uniformly coated with silver metal. The powder can be cold worked (e.g., swaged, forged, etc.) to form superconducting structures such as rods or wires.

Abstract: An improved method for the preparation of single phase, fine grained ceramic materials from precursor powder mixtures where at least one of the components of the mixture is an alkali earth carbonate. The process consists of heating the precursor powders in a partial vacuum under flowing oxygen and under conditions where the partial pressure of CO.sub.2 evolved during the calcination is kept to a very low level relative to the oxygen. The process has been found particularly suitable for the preparation of high temperature copper oxide superconducting materials such as YBa.sub.2 Cu.sub.3 O.sub.x "123" and YBa.sub.2 Cu.sub.4 O.sub.8 "124".

Abstract: A high temperature superconductor is provided having meltability. The superconductor has a preferred composition of Tb-R-Ba-Cu-O wherein R is chosen from the group of rare earth metals excluding: Praseudyium; Cerium; and Terbium.

Abstract: A process of making high-temperature Tl-based superconductors. The process includes the steps of reacting solid Ba-Ca-Cu-oxides with Tl.sub.2 O.sub.3 vapor. The process allows high quality Tl-based superconductors to be easily fabricated.

Abstract: This invention relates to homogeneous copper-containing oxide superconductors with improved superconducting properties and a process for preparing them.

Abstract: The invention relates to production of superconductors, more particularly, LnM.sub.2.sup.II M.sub.3.sup.I O.sub.y compounds where y=6-8; Ln=Y, Sc or lanthanide; M.sup.II =Ba, Ca or Sr; M.sup.I =Cu, Cu+Ag or LnM.sub.2.sup.II M.sup.I O.sub.y-x F where x=1-2. It comprises local initiation of an exothermic reaction in a stoichiometric mixutre of source constituents chosen to provide for production of the afore-mentioned compounds. An exothermic mixture of corresponding constituents includes a non-combustible component and a combustible component comprising at least one metal from the group composed of a rare-earth metal of the periodic system chosen from scandium, yttrium and lanthanide, a metal of group II of the periodic system, a metal of group I of the periodic system or hydride of at least one of said metals.

Abstract: A method for fabricating a low resistivity target for sputtering a bismuth-calcium-strontium-copper oxide superconductor. The method includes the steps of: preparing ingredient powders of a calcium carbonate, a strontium carbonate and a copper oxide; producing a porous bulk body of a complex oxide from the ingredient powders; and impregnating molten bismuth into the porous bulk body of the complex oxide.

Abstract: A manufacturing method of Josephson devices is described. A superconducting ceramic film is deposited on a non-conductive surface and partly spoiled in order to form a barrier film by which two superconducting regions is separated. The spoiling is performed by adding a spoiling element into the ceramic film by ion implantation.

Abstract: A sintered elongated core made of a ceramic type superconductive material consisting essentially of (R.sub.x Ba.sub.(1-x)).sub.3 Cu.sub.2 O.sub.z in which R is Sc, Y La, Ho, Dy or Eu; x is in the range of from 0.3 to 0.8; and z is in the range of from 6 yo 7, is encased in glass and then heated, stretched and drawn.

Abstract: This invention provides a method for producing an oxide superconductor which has a uniform texture and is markedly high in sintered density and current density.The method involves the formation of intermediate products from the starting materials. The intermediate products are then used to form the final product. Specifically, to form an oxide superconducting material having a compositional formulaYBa.sub.2 CU.sub.3 O.sub.7-8,where 8 is more than zero but less than 0.5, the method of the invention includes forming a first intermediate product of Y.sub.2 CU.sub.2 O.sub.5, forming a second intermediate product of BaCuO.sub.2, mixing the first and second intermediate products, and sintering the intermediate product mixture to form the oxide superconducting material.

Abstract: Improvement in a method for producing superconductors of thallium (T1) type compound oxides by sintering a material powder mixture including at least one thallium-containing powder, the method including wrapping the material powder mixture in a foil of precious metals or their alloys and placing the wrapped material powder in a pipe of precious metals or their alloys and having an opening, wherein the material powder mixture wrapped in the foil is sintered in the pipe while oxygen gas is supplied into the pipe through the opening.

Abstract: A superconducting wire is produced by the surrounding of a superconductive material core with an intermediate compressible insulating layer and an outer malleable layer and then drawing said composite structure through a series of dies to reduce the diameter of the wire on the order of 400 to 10,000 times or by reducing the superconductive core material to the desired wire size by passing it through a series of dies to reduce the diameter of the wire on the order of 400 to 10,000 times and then coating the wire with a noncompressible insulating layer and then placing an outer malleable layer over the insulated wire and drawing this through dies to snuggly fit the outer layer onto the insulated wire. This wire's superconducting characteristics are not intended for carrying high levels of currents so the reduction of the available current carrying cross section by the introduction of the insulating layer is not of concern in the applications for the wire.

Abstract: The present invention describes a method to produce a patterned superconducting solid preferably as a thin film. Unsaturated organic acid metal salts of suitable metals are dissolved in an organic solvent, mixed thoroughly and cast as a film on a substrate. The concentration of these organic carboxylate metal salts is adjusted such that a superconducting metal oxide ratio is obtained upon pyrolysis at temperatures up to 1000.degree. C. with subsequent slow cooling. A pattern (mask) is placed over the film and the film is irradiated to polymerize and crosslink the exposed portions. The unpolymerized and uncrosslinked portions are removed usually by using selective solvents or solvent mixtures. The solid remaining is heated in oxygen or air to about 1000.degree. C., which removes the organic portions and leaves metal oxide residue. The metal oxides are then cooled slowly and annealed to produce the patterned metal oxide superconducting materials.

Abstract: A method for producing high-temperature superconducting ceramic material through mechanical orientation including mixing starting materials in powdered form in proportions effective to produce a high-temperature superconducting oxide ceramic having anisotropic crystal grains and shaping the mixture. Next, the shaped mixture is calcined at a temperature ranging from 600.degree. to 900.degree. C. and fired at a temperature higher than 1,000.degree. C. in an oxygen atmosphere for a time effective to produce a superconducting oxide ceramic having crystal grains. According to the invention, the superconductive oxide ceramic is then pulverized into particles having either a plate-like form or a needle-like form based on the anisotropic form of the crystal grains. Particles of a selected size are placed into a vessel and vibrated with an acoustic vibrator means under conditions effective to cause the pulverized particles to turn toward a common preferred orientation to provide oriented particles.

Abstract: A superconducting ceramic powder of Bi/Sr/Ca/Cu/O system are formed in a film and the c-axes are uniformly aligned with the normal of the film. The alignment of the axes is accomplished by dripping ethylalcohol containing the ceramic powder into ethyl alcohol contained in a reservoir. The ceramic powder is settled on a substrate arranged in the reservoir in film form. After removing ethylalcohol, the ceramic film is fired.

Abstract: A method for forming metallized coatings on ceramics for high-temperature uses above about 630.degree. C. comprising the steps of: preparing a metallizing composition of mixed ingredients of differing sizes, proportioning the differing sizes to have nonsegregating qualities when applied onto the ceramics, coating the metallizing composition on the ceramics; and heating to form the desired metallized layer.

Abstract: An inorganic powder is vibrated while being calcined. The vibrations suspend the powder as in a conventional gas-fluidized system, without clumping, but without loss of fines. As applied to superconductor precursor powders, the treatment accelerates growth of the superconducting phase. The invention includes a novel furnace system for simultaneously heating and vibrating the powders.

Abstract: The specification discloses forming ceramic films, and especially high temperature superconductor films, by dissolving ceramic precursor metal iodides in organic solvents, applying them to a substrate, evaporating the solvent and pyrolyzing and annealing the resulting ceramic precursor metal iodide films.

Abstract: A superconductive thin layer of an oxidic material is manufactured by contacting at least two starting substtances with each other, after which diffusion and a chemical reaction in the solid state occur by means of increasing the temperature, while forming the superconductive thin layer.

Abstract: A process for silver coating superconducting ceramic powder by(1) coating the superconducting ceramic powder particles with AgNO.sub.3 ;(2) melting the AgNO.sub.3 so that it wets and forms a uniform coating over the surfaces of the particles; and(3) decomposing the AgNO.sub.3 to form a thin, uniform coating of silver metal on the surfaces of the particles.The product is a loose powder of the superconducting ceramic particles which are uniformly coated with silver metal. The powder can be cold worked (e.g., swaged, forged, etc.) to form superconducting structures such as rods or wires.

Abstract: A method for improving the superconducting transition temperature of the MBa.sub.2 Cu.sub.3 O.sub.x where M is selected from the group consisting of Y, Er, Eu, Yb, Dy and Ho and where x is a value of from 6 to 7 ceramic by utilizing specific sequences of heat treating times and temperatures in conjunction with the use of silver oxide in making superconducting devices or wires for ultimate use in motors, generators and electrical circuits.

Abstract: A method for producing a metal-oxidic superconductor material with a high transition temperature and an increased critical current density. The method comprises applying a layer of a metal-oxidic preliminary product comprising the components of the metal-oxidic material, with a crystal structure still having faults, to a substrate, and subsequently, forming the desired superconducting metal-oxide phase by means of a heat and oxygen treatment, where a critical current density of the layer is greater parallel to the surface of the layer than in the direction of the normal of the layer, and wherein the preliminary product is moved through a heated zone parallel to the surface of the layer at a predetermined velocity, wherein the zone has a positive maximum temperature gradient (.DELTA.T/.DELTA.x) measured in the direction of motion, of at least 5 K/mm and preferably of at least 10 to 50 K/mm.

Abstract: This invention provides a process for the preparation of the precursor used in the fabrication of Y--Ba--Cu--O superconductors. This process mainly uses solgel technology via the nitrate route by using a dicarboxylic acid. Among the dicarboxylic acids, oxalic acid is the best for preparing the precursor which can be fabricated into a good superconductor.

Abstract: A method for fabricating relatively dense monoliths of superconducting material and relatively dense composite monoliths of superconducting material and binder material. The method includes the steps of placing the material to be processed in a die. A relatively high pressure is then applied to the material. Substantially simultaneously, an electrical discharge is applied to the material. The discharge is of a relatively high voltage and current density to provide sharp bonding while maintaining the superconducting properties of the material in the monolith product. A product fabricated by the present method is also described.