Abstract: A large superconductor intermediate of REBa2Cu3Ox system (where RE is one kind or a combination of rare earth elements including Y), characterized by a structure that oxide superconductors having non-superconductive phases finely dispersed in REBa2Cu3Ox phases (123 phases) of different peritectic temperatures (Tp) are laminated three-dimensionally in the order of Tp's, seed crystals mounted on the oxide superconductor layer having a highest Tp, and excluded phases included in at least the oxide superconductor having the high Tp.

Abstract: A copper-based high-temperature superconducting material includes a carrier supply layer overdoped with carriers; and a superconducting layer comprised of at least three CuO2 layers that are selectively doped with the carriers; whereby a high superconducting transition temperature (Tc) is maintained to be not less than 116 K, critical current density (Jc) is improved to be 5×106 A/cm2 (77 K, 0 T), and irreversible field (Hirr) is improved to be not less than 7 T.

Abstract: A Mg-doped high-temperature superconductor having low superconducting anisotropy includes a two-dimensional layered structure constituted by a charge reservoir layer and a superconducting layer, wherein some or all atoms constituting the charge reservoir layer are Cu and O atoms, metallizing or rendering the charge reservoir layer superconducting, a portion of the Ca of the CunCan−1O2n constituting the superconducting layer is replaced by Mg, increasing superconductive coupling between CuO2 layers, a thickness of the superconducting layer is increased, and therefore coherence length in a thickness direction is increased based on the uncertainty principle, lowering superconducting anisotropy.

Abstract: A thin-film of a high temperature superconducting compound having the formula M1-xCuO2-y, where M is Ca, Sr, or Ba, or combinations thereof, x is 0.05 to 0.3, and x>y. The thin film has a Tc (zero resistivity) of about 40 K. Also disclosed is a method of producing the superconducting thin film.

Abstract: A material having a superconducting transition temperature (Tc) of 126 K under ambient pressure has been identified. The superconducting material belongs to a Ba—Ca—Cu—O compound family where the cation ratio of Ba:Ca:Cu is 2:2.5+0.5:3.5±0.5. The superconducting material is produced from precursor oxides having nominal formula Ba2Can−1+xCuu/yOx wherein n=3 or 4 and x is 0.4 to 1.0 and y is 0 to 0.8 using high-pressure synthesis. Final synthesis temperature was maintained at less than 950° C. Formation of the superconducting material is sensitive to the state of the precursor oxides, the carbon content of the precursor, and the synthesis temperature, pressure and time.

Abstract: The invention provides superior reaction products of copper, especially ultra-clean copper and polymeric chemical complexes. The polymers are unusual in that they provide polymeric systems of extensive conjugated double bond networks well suited for electron flow. The polymers are the covalent reaction products of aroylacrylates and isocyanates or thioisocyanates and are of stability and ease of manufacture.The materials provide superior electrical conductors and superconductors. Through the use of lattice modifiers and stabilizers the lattices of the polymers may be "fine tuned" easily so as to optimize important characteristics such as electron flow.The organic coatings on the copper perform best as thin films, especially as films thinner than lambda, the penetration depth of the magnetic flux into the superconductor. The long term widely accepted use of copper as an electrical conductor, with its flexibility, durability, and strength is preserved while its electrical current capacity is greatly enhanced.

Abstract: A mixture suitable for the production of melt-processed high-temperature superconductors capable of producing a high levitation force. The mixture contains YBa.sub.2 Cu.sub.3 O.sub.7-x powder with a very low content of copper oxide, i.e. copper not bound in with the YBa.sub.2 Cu.sub.3 O.sub.7-x, and a very low carbon content. Also included are stabilizing (so-called "flux-pinning") additives. Also disclosed is a method or producing the mixture, as well as YBa.sub.2 Cu.sub.3 O.sub.7-x powder with suitable low free copper oxide and carbon contents, used to prepare the mixture.

Abstract: The present invention relates to a process for preparing a high-T.sub.c superconductor as a precursor material for the oxide-powder-in-tube method, which involves mixing the oxides of the elements Bi, Sr, Ca and Cu and completely melting them at temperatures of .gtoreq.1000.degree. C., then casting the melt onto a substrate which is kept at room temperature, and disintegrating the cooled melt block and grinding it into a powder.

Abstract: There are disclosed a high temperature superconductive material which can be plastically deformed, processed optionally into predetermined configurations and industrially mass produced and a method of manufacturing a formed body of the high temperature superconductive material. Mixed is a powder raw material which is mainly composed of: 10 to 50 mol % of at least one amide or nitride of alkali metal of Li, Na or K; 10 to 60 mol % of cyanide containing at least one metal selected from aluminum, copper, silver or gold; 5 to 50 mol % of at least one pure metal selected from aluminum, copper, silver or gold; and 10 mol % or less of at least one alkaline earth metal selected from Be, Mg, Ca, Sr or Ba. The powder raw material is pressed, and heated and sintered at the temperature of 673 K to 1553 K. In this manner, obtained is the plastically deformable high temperature superconductive material which can be optionally processed through forging, rolling and the like.

Abstract: Compounds of the of the general formula La.sub.3-z Me.sub.z Ba.sub.3 Ca.sub.1-v Nc.sub.v Cu.sub.7 O.sub.16+x, wherein Me can be a rare earth metal or an alkaline metal ion selected from the group consisting of yttrium (Y), ytterbium (Yb), sodium (Na) and Nc can be a 2+ion selected from the group consisting of magnesium (Mg) and cadmium (Cd) have been prepared as the HTSC in thin film superconductors. These compounds can be used as thin film high critical superconductors in thin film high critical temperature superconducting structures and antennas and in multilayered structures and devices such as Josephson junctions, broadband impedance transformers and both flux flow and field effect transistors.

Abstract: The present invention relates to method of preparing a superconductor material consisting in preparing a precursor constituted by a powder of Ba.sub.2 Ca.sub.n-1 Cu.sub.n+1 O.sub.x or Ba.sub.2 Ca.sub.n-1 Cu.sub.n+1 O.sub.x where n is an integer greater than 1 and x is greater than 2n+2; in mixing said powder with silver oxide power, optionally in the presence of excess copper oxide, in a proportion of one mole of precursor for one to three moles of silver oxide; and in heating to high temperature and high pressure.

Abstract: A high temperature superconductor which has a layered crystal structure, which has a superconducting transition temperature, Tc, of 110 K or more, and which has a composition expressed by:Cu.sub.1-z M'.sub.z Ae.sub.2 Ca.sub.x-1 Cu.sub.x O.sub.y,where M' is at least one element selected from the group consisting of (a) trivalent ions of Tl, and (b) polyvalent ions of Mo, W, and Re,where Ae is at least one of Ba and Sr,where x ranges from 1 to 10,where y ranges from 2x+1 to 2x+4, andwhere z ranges from 0<z.ltoreq.0.5.

Abstract: A material formed as a film comprised of monomolecular layers (2,3,4,5) stacked on a substrate (1), wherein said film includes at least one first set (R) of layers which form an electric charge reservoir, and a second set (S) of layers which form a conductive cell and which contain a number of conductive copper oxide layers (4), separated from each other by intermediate layers (5), the reservoir and the conductive cell being adjacent in the layer stack. There are at least four conductive copper oxide layers, and the intermediate layers have the chemical formula Ca.sub.1-x M.sub.x and are free of strontium, wherein x is a real number between 0 and 0.2, M is a component with an ionic radius close to that of the Ca.sup.2+ ion, and the intermediate layers may be complete or not.

Abstract: There is disclosed herein an invention for increasing the current carrying capability of high-Tc superconductor materials. The inventive method includes irradiating such superconductors with light particles, such as neutrons, protons and thermal neutrons, having energy sufficient to cause fission of one or more elements in the superconductor material at a dose rate and for a time sufficient to create highly splayed (dispersed in orientation) extended columns of damaged material therein. These splayed tracks significantly enhance the pinning of magnetic vortices thereby effectively reducing the vortex creep at high temperatures resulting in increased current carrying capability.

Abstract: Highly oriented HgBa.sub.2 Ca.sub.2 Cu.sub.3 O.sub.8+.delta. on Ni-tapes with a buffer layer of Cr/Ag or Cr/(Ag--Pd) have been described with a high transition temperature are described along with, one and two step methods of manufacture.

Abstract: A Hg-based superconducting cuprate film on a substrate is disclosed, which comprises a compound having the formula Hg.sub.1-x M.sub.x Ba.sub.2 Ca.sub.n-1 Cu.sub.n O.sub.y, M is a metal cation, x ranges from 0 to 1, n is an integer greater than 0, and y is an oxygen sufficiency factor having a value less than about 10.

Abstract: The present invention is directed to a process for preparing a HgBaCaCuO superconductor by annealing a precursor mixture comprising a lower member of the homologous HgBaCaCuO superconductor series, a source of calcium and a source of copper. The precursor mixture may further comprise a source of oxygen, a source of rhenium, and, if desired, a source of an additional element selected from the group consisting of halogens and metals other than mercury, barium, calcium, copper and rhenium. The process is particularly effective for preparing (Hg.sub.1-x,Re.sub.x)Ba.sub.2 Ca.sub.2 Cu.sub.3 O.sub.8-y by annealing a precursor mixture containing (Hg.sub.1-x,Re.sub.x)Ba.sub.2 Ca.sub.1 Cu.sub.2 O.sub.6-y at a temperature below about 850.degree. C., wherein x ranges up to about 0.25 and y is a rational number ranging from about negative 1 to about positive 1.

Abstract: Novel superconducting oxide material containing compound oxide having a composition represented by the formula:?(Tl.sub.1-x Bi.sub.x).sub.1-p .alpha..sub.p !.sub.q Sr.sub.y Ca.sub.z Cu.sub.v O.sub.win which ".alpha." is at least one element selected from a group consisting of In, Sn, Sb, Pb, Y and lanthanide elements and "x", "y", "z", "p", "q", "v" and "w" are numbers each satisfying respective range of 0.ltoreq.x.ltoreq.1.0, 0.5.ltoreq.y.ltoreq.4.0, 0.5.ltoreq.z.ltoreq.4.5, 0.ltoreq.p.ltoreq.0.6, 0.5.ltoreq..ltoreq.3.0, and 1.0.ltoreq.v.ltoreq.5.5.

Abstract: A high critical temperature and high critical current density superconductor is disclosed which contains a metal oxide expressed by the following formula (I):(R.sup.1.sub.1-x, Ba.sub.x)Ba.sub.2 Cu.sub.3 O.sub.d (I)wherein R.sup.1 stands for at least one element selected from the group consisting of La, Nd, Sm, Eu and Gd, x is a number greater than 0 but not greater than 0.5 and d is a number between 6.2 and 7.2. Fine phases of RE211, RE422 and/or a metal oxide expressed by the formula (R.sup.2.sub.1-z, Ba.sub.z) (Ba.sub.1-y, R.sup.2.sub.y).sub.2 Cu.sub.3 O.sub.p (R.sup.2 =La, Nd, Sm, Eu or Gd) may be dispersed in a matrix of the matrix phase of the formula (I). The above superconductor may be obtained by cooling a melt having a temperature of 1,000.degree.-1,300.degree. C. and containing R.sup.1, Ba, Cu and O at a cooling rate of 5.degree. C./hour or less under a partial pressure of oxygen of between 0.00001 and 0.05 atm, followed by annealing at 250.degree.-600.degree. C. in an oxygen atmosphere.

Abstract: Alkaline-doped superconductors of the formulaX M.sub.2 Ca.sub.2 Cu.sub.3 O.sub.8+.alpha.are provided where X is selected from the group consisting of TI, Pb, Mo, Hg and mixtures thereof, M is selected from the group consisting of Ba, Sr and mixtures thereof, and a ranges from zero to about 0.2, and being doped with a dopant selected from the group consisting of Na and Li up to a level of up to about 12% molar ratio, based upon the amount of the element X taken as 100%. The superconductors of the invention exhibit extremely high T.sub.c onset and T.sub.cO values and have high J.sub.c properties as well. The superconductors can be fabricated at relatively low annealing temperatures (750.degree.-820.degree. C.) making them suitable for use as thin films with a variety of conventional substrates.

Abstract: The invention relates to a spray pyrolytic process for the preparation of multi-element metal oxide powders useful as precursors of high temperature superconductor ceramics. Aerosols of aqueous solutions containing corresponding metal salts admixed in the required stoichiometric proportion are sprayed through an independently operated hydrogen/oxygen flame in such a way that a flame temperature of 800.degree.-1100.degree. C. is maintained to form said powders. Any contact of the aerosols and powders generated during the process with carbon or carbon-containing compounds or materials is strictly avoided.

Abstract: Hg,Tl-based superconductors are produced by HIPping. A new superconducting phase, having a double (Hg,Tl)-layer and the nominal composition:(Hg.sub.1-x Tl.sub.x).sub.2 (Ba.sub.1-a Sr.sub.a).sub.2 (Ca.sub.1-b Y.sub.b).sub.2 Cu.sub.3 O.sub.zwhere 0.ltoreq.x.ltoreq.0.95, 0.ltoreq.a.ltoreq.1, 0.ltoreq.b.ltoreq.1, and z is sufficient to provide said phase with a resistive and magnetic superconducting transition of 100K or above, can be produced. Either precursor oxides, or partially or fully reacted mixed oxides, can be used in the HIPping mixture.

Abstract: The hole density of an oxide superconductor having holes as carriers is higher than the hole density to bring the highest value of the superconductivity critical temperature Tc thereof, and it can be made higher than the optimal density to bring the highest Tc value by treating the oxide superconductor with heat in an oxidizing gas atmosphere, or by replacing positive ions constituting the oxide superconductor except for copper with ions of a low valence number. Accordingly, it is possible to substantially reduce the rate of decrease of the critical current density owing to an applied magnetic field when the magnetic field is applied parallel to the crystal c axis, and to allow a current conductor produced by using the oxide superconductor to have high critical current density.

Abstract: A new use as high critical temperature superconductors, of a known family of partially oxidized bi-metal compounds in which the two metals are copper and barium. These compounds become superconductive at least at a temperature higher than 5.degree. K. but less than or equal to 77.degree. K., when oxygen vacancies are located symmetrically with respect to the axes of their lattice structure.

Abstract: The present invention is an oxide superconductor containing alkaline earth metal M (where M is at least one element of Ba, Sr, and Ca) and having a crystalline structure in which a portion based on two rock-salt structures including the alkaline earth metal M, oxygen, and chlorine, and a 2n-1 piece of infinite layer structure portion are alternately layered on each other, said 2n-1 piece of infinite layer structure portion having an atom layer including copper atoms and oxygen atoms in a ratio of 1 to 2 and of an atom layer including only M atoms layered on each other (where n is an integer of 1 or more and where copper atoms and oxygen atom are contained in a ratio of 1 to 2 if n is 1).

Abstract: The present invention provides an oxide superconductor which is expressed in the composition formula(Pb.sub.1-x-y M.sub.x (A1).sub.y)(A2).sub.2 (A3).sub.n-1 (Cu).sub.n (O).sub.2n+3+z(wherein 0.ltoreq.0.6, 0.ltoreq.y.ltoreq.0.6, x+y.ltoreq.0.6, n denotes integers of 1 or more, -0.6.ltoreq.z.ltoreq.0.5, M denotes Cu or Cd, and A1, A2 and A3 denote at least one element of Ba, Sr, and Ca, respectively) and which has a crystal structure stacking rock salt structure based portions and infinite layer structure portions, wherein the rock salt structure based portion has a structure that an atoms layer having 0.5-1.5 oxygen atoms, in case the total atoms number of Pb, M and A1 is one, and an atoms layer having one or less oxygen atoms per one A2 atom, are stacked and the infinite layer structure portion has a structure that an atoms layer having 2 oxygen atoms per one Cu atom and an atoms layer of A3 atoms only, are stacked.

Abstract: An oxide superconductor composed of Cu, O and M (M is Ba, Sr and/or Ca) and including alternately arranged at least one rock-salt structure section and at least one infinite layer structure section, wherein the rock-salt structure section consists of two atomic layers each consisting of O and M and each having an atomic ratio O/M of 1 or less, and the infinite layer structure section consists of alternately arranged, first and second atomic layers. Each of the first atomic layers consists of O and Cu and has an atomic ratio O/Cu of 2, while each of the second atomic layers consists of the element M. The infinite layer structure section may consist of only one first atomic layer.

Abstract: An oxide superconductor having a composition of the formula: A.sub.n+1 Cu.sub.n O.sub.2n+1+.delta. in which A is at least one alkaline earth metal element selected from the group consisting of calcium, strontium and barium, n is an integer of at least one, and .delta. is a number larger than 0 and not larger than 1, a laminate structure in which a layer having a partial composition of A.sub.2 O.sub.1+.delta. and a layer having a partial composition of A.sub.n-1 Cu.sub.n O.sub.2n are alternately laminated, and a superconductive critical temperature equal to or higher than the liquid nitrogen temperature.

Abstract: An oxide superconductor composed of Cu, O and at least one of Ba, Sr and Ca and including alternately arranged at least one oxygen-deficient perovskite structure section and at least one infinite layer structure section, wherein the perovskite structure section consists of two first atomic layers and a second atomic layer sandwiched between the first layers, and wherein the infinite layer structure section consists of alternately arranged, third and fourth atomic layers. Each of the first layers consists of O and an element M.sup.1 selected from Ba, Sr and Ca and has an atomic ratio O/M.sup.1 of 1 or less, while the second layer consists of O and Cu and has an atomic ratio O/Cu of 2 or less. Each of the third layers consists of O and Cu and has an atomic ratio O/Cu of 2, while each of the fourth layers consists of an element M.sup.2 selected from Ba, Sr and Ca. A superconductor having a superconducting critical temperature of over 100 K. may be produced by heat treatment at 800.degree.-1,200.degree.C.

Abstract: Process for preparing a high-T.sub.c superconductor as a precursor material for the oxide-powder-in-tube method (OPIT). The present invention relates to a process for preparing a high-T.sub.c superconductor as a precursor material for the oxide-powder-in-tube method, which involves mixing the oxides of the elements Bi, Sr, Ca and Cu and completely melting them at temperatures of >1000.degree. C., then casting the melt onto a substrate which is kept at room temperature, and disintegrating the cooled melt block and grinding it into a powder.

Abstract: A high-temperature superconductor material based on the Bi--Sr--Ca--Cu--O system has the nominal composition:(Bi.sub.1-u Pb.sub.u).sub.2 (Sr.sub.1-x-y Ca.sub.x Bi.sub.y).sub.4 Cu.sub.3 O.sub.10+d (d=delta)wherein 0.01<x<0.50.ltoreq.y<x<0.50.ltoreq.d0.ltoreq.u.The high-temperature superconductor material has a transition temperature greater than 90.degree. K.

Abstract: The fabrication of superconducting wires and rods having desired and consistent electrical and mechanical properties, in particular those based on Yttrium Barium Copper Oxide (YBCO) and Bismuth Strontium Calcium Copper Oxide (BSCCO), is disclosed. The first fabrication step is to form an extrudable paste by mixing YBCO or BSCCO superconducting powder with a set of organic additives, which include binder, plasticizer, lubricant, dispersant, and a solvent. The following additional steps are performed on both YBCO and BSCCO based wires or rods: (i) using a piston extruder to extrude the superconducting wire or rod; (ii) drying the wire or rod to remove the solvent; and (iii) subjecting the wire or rod to a binder burn-out treatment to remove the remaining organic additives. In addition, YBCO wires and rods also require a sintering step, while BSCCO wires and rods also require cold isostatic pressing and heat treatment steps.

Abstract: A superconducting film is disclosed which has the following composition:(Nd, Ba).sub.3 Cu.sub.3 O.sub.7-dwhere d is a number greater than 0 but smaller than 0.5. The superconducting film has the same crystal structure as that of YBa.sub.2 Cu.sub.3 O.sub.7 except that part of the Nd sites and/or part of the Ba sites are occupied by Ba and Nd atoms, respectively.

Abstract: The invention relates to a spray pyrolyric process for the preparation of multi-element metal oxide powders useful as precursors of high temperature superconductor ceramics. Aerosols of aqueous solutions containing corresponding metal salts admixed in the required stoichiometric proportion are sprayed through an independently operated hydrogen/oxygen flame in such a way that a flame temperature of 800.degree.-1100.degree. C. is maintained to form said powders. Any contact of the aerosols and powders generated during the process with carbon or carbon-containing compounds or materials is strictly avoided.

Abstract: Provided is an Hg--Ba--Ca--Cu--O oxide superconductor having a high superconductivity transition temperature Tc and a method which can prepare the same in excellent reproducibility. This oxide superconductor consists essentially of Hg, Ba, Ca, Cu and O, and is expressed in a chemical formula (Hg.sub.1-X Cu.sub.X)Ba.sub.2 Ca.sub.2 Cu.sub.3 O.sub.y, wherein X=0.05 to 0.7 and Y=8 to 8.75. A method of preparing the oxide superconductor comprises a step of mixing raw materials of Hg, Ba, Ca and Cu with each other so that (Hg+Ba):Ca:Cu =b:1:C and Hg:Ba=(1-a):a, wherein 0.625.ltoreq.a.ltoreq.0.714, 1.ltoreq.b.ltoreq.3 and 1.667.ltoreq.c.ltoreq.3.444, in mole ratio, and compression-molding the mixture, and a step of heat treating a compact obtained by the compression molding. This oxide superconductor has a superconductivity transition temperature Tc of 134 K, which is the highest at present.

Abstract: Processes are provided for forming a superconductive composite, comprising a superconductive metal oxide and a ceramic. The composite may be formed in any desired shape. Liquid nitrogen can be held around the superconductor longer and delivered in a more controlled fashion and the composite has improved resistance to shatter and thermal shock. The ceramic also provides protection from atmospheric deterioration of the superconductive oxide.

Abstract: A process of manufacturing a superconducting compound including mixing stoichiometric amounts of a metallic oxide, copper oxide and a metallic carbonate wherein the metal of the metallic oxide is one other than yttrium and is selected and identified by its intrinsic massivity which is close in value to the intrinsic massivity of yttrium and wherein the interplanar distance on the C axis between Cu--O planes that exchange electrons through the electron-hopping mechanism in the ceramic perovskite is within the range of 1.97 .ANG. and 1.01 .ANG.. The mixture is subjected to pressure to form pellets and the pellets are then heated in forming the compound. The compound produced by the process and ceramic compositions having the formulas Mn Sr.sub.2 Cu.sub.3 O.sub.7-x and Mn.sub.2 Sr.sub.2 Cu.sub.3 O.sub.7-x.

Abstract: Provided is a metal oxide material represented by the composition formula of Ln.sub.a Sr.sub.b Cu.sub.3-x M.sub.x O.sub.c, where 2.7.ltoreq.a+b.ltoreq.3.3; 0.8 .ltoreq.a.ltoreq.1.2; 6.ltoreq.c.ltoreq.9; and 0.05 .ltoreq.x.ltoreq.0.7, Ln is at least one element selected from the group of elements of Y and lanthanoids or an atomic group consisting of said elements, and M is at least one element selected from the group of elements of Ti, V, Ga, Ge, Mo, W and Re or an atomic group consisting of said elements.

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 sec-butoxy 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 metal oxide material comprises components, the composition of which is expressed by the following composition formula (I):Ln.sub.a Ca.sub.b Sr.sub.c Ba.sub.d Cu.sub.2+e-h M.sub.h O.sub.6+f C.sub.g(I)wherea+b+c+d=3, 0.2.ltoreq.a.ltoreq.0.8,0.2.ltoreq.b.ltoreq.1.0, 0.3.ltoreq.c.ltoreq.2.2,0.ltoreq.d.ltoreq.1.7, 0.ltoreq.e.ltoreq.0.8,0.ltoreq.h.ltoreq.0.2, 0<f<2.0,0.2.ltoreq.g.ltoreq.1.0,Ln is one or more elements or atomic groups selected from a group consisting of Y and lanthanoid elements and M is one or more elements or atomic groups selected from a group consisting of Al, Si, Ti, V, Cr, Fe, Co, Ga, Ge and Pd.

Abstract: The present invention is a controlled vapor/solid reaction process for the synthesis of samples of bulk compositions with a structure defined by the homologous series HgBa.sub.2 Ca.sub.n-1 Cu.sub.n O.sub.2n+2+.delta. [Hg-12(n-1)n] with n=2, 3, . . . with up to 75 to 90% Hg-1212 and 65 to 75% Hg-1223 by volume, which display sharp superconducting transitions up to 135 K.

Abstract: Disclosed are a composition and a method of preparing a composition of the formula R.sub.2 Q.sub.4 Cu.sub.7 O.sub.x, wherein R is a rare-earth ion or a mixture of rare earth ions, and Q is Ba, or Ba combined with either Sr or Ca or both Sr and Ca. Such compositions have a unique crystalline structure and are superconducting oxides.

Abstract: Improved superconducting oxides are provided having the general formula (Hg.sub.1-x Tl.sub.x)Ba.sub.2 Ca.sub.n-1 Cu.sub.n O.sub.2n+2+.alpha. where x is from about 0.05-0.5 and n is 1, 2, 3 or 4, and .alpha. is an oxygen enrichment factor. The Tl-doped oxides exhibit very high T.sub.c and J.sub.c values.

Abstract: Superconducting compositions characterized by the formula (Pb.sub.a A.sub.1-a)(Sr.sub.b Ba.sub.1-b).sub.2 (Ca.sub.c B.sub.1-c)Cu.sub.2 O.sub.7 wherein at least half the A atoms are Hg and the remainder, if any, are selected from one or more of Cd, Tl and Cu, B is selected from Y and the rare earths, a is from 0.3 to 0.7, b is from 0 to 1 and c is from 0.2 to 0.5 are disclosed. The superconductive compositions display zero-resistance temperatures up to about 80K.

Abstract: A family of mercury-containing Sr-(Ca.cndot.Y)-Cu-O superconducting materials having a zero-resistance temperature, T.sub.c(zero), greater than 90 K so that they can be cooled to and maintain the desired superconducting characteristics using relatively less expensive liquid nitrogen, are disclosed. The high-temperature superconductor is represented by the formula of: (Pb.sub.0.5 Hg.sub.0.5)(Sr.sub.2-x Ba.sub.x)(Ca.sub.0.7 Y.sub.0.3)Cu.sub.2 O.sub.7-.delta. ; wherein the value of x ranges between about 0.1 and about 0.6, preferably between about 0.2 and about 0.3. These superconducting materials are prepared by first grinding and mixing in open air constituent oxide powders of PbO, HgO, SrO.sub.2, BaO.sub.2, CaO, Y.sub.2 O.sub.3, and CuO. After mixing, the powder mixture is pressed under a pressure of about 5 ton/cm.sup.2 to form a pellet having a diameter of 8 mm and a thickness of 3 mm. Thereafter, the pressed pellet is wrapped with a gold foil (with a thickness of 0.

Abstract: Provided is an Hg-Ba-Ca-Cu-O oxide superconductor having a high superconductivity transition temperature Tc and a method which can prepare the same in excellent reproducibility. This oxide superconductor consists essentially of Hg, Ba, Ca, Cu and O, and is expressed in a chemical formula (Hg.sub.1-X Cu.sub.X)Ba.sub.2 Ca.sub.2 Cu.sub.3 O.sub.Y, wherein X=0.05 to 0.7 and Y=8 to 8.75. A method of preparing the oxide superconductor comprises a step of mixing raw materials of Hg, Ba, Ca and Cu with each other so that (Hg+Ba):Ca:Cu=b:1:C and Hg:Ba=(1-a):a, wherein 0.625.ltoreq.a.ltoreq.0.714, 1.ltoreq.b.ltoreq.3 and 1.667.ltoreq.c.ltoreq.3.444, in mole ratio, and compression-molding the mixture, and a step of heat treating a compact obtained by the compression molding. This oxide superconductor has a superconductivity transition temperature Tc of 134 K., which is the highest at present.

Abstract: A Bi--Sr--Ca--Cu--O ceramic superconductor contains 0112 phases which are finely dispersed in a 2212-phase matrix with its c-axis oriented perpendicular to a growth direction.A method of preparing a Bi--Sr--Ca--Cu--O ceramic superconductor comprises the steps of growing crystals under conditions satisfying:G/R.gtoreq.1 and G.multidot.R.gtoreq.10000where G (K/cm) represents the temperature gradient at a solid-liquid interface and R (mm/h) represents the rate of crystal growth, and annealing the grown crystals in an atmosphere having oxygen partial pressure of at least 0.05 atm. within a temperature-range of 800.degree. to 860.degree. C. for at least 2 hours.

Abstract: In accordance this invention, there is provided a process for making a bulk superconductive material. In the first step of this process, a diffusion couple is formed from superconductor oxide and impurity oxide. Thereafter, the diffusion couple is heated to a temperature in excess of 800 degrees Centigrade, cooled at a controlled rate, and annealed.

Abstract: Novel superconducting oxide material containing compound oxide having a composition represented by the formula:[(Tl.sub.1-x Bi.sub.x).sub.1-p .alpha..sub.p ].sub.q Sr.sub.y Ca.sub.z Cu.sub.v O.sub.win which ".alpha." is at least one element selected from a group consisting of In, Sn, Sb, Pb, Y and lanthanide elements and "x", "y", "z", "p", "q", and "v" are numbers each satisfying respective range of 0.1.ltoreq.x.ltoreq.0.5, 0.5.ltoreq.y.ltoreq.4.0, 0.5.ltoreq.z.ltoreq.4.5, 0.ltoreq.p.ltoreq.0.6, 0.5.ltoreq.q.ltoreq.3.0, and 1.0.ltoreq.v.ltoreq.5.5.

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.