Abstract: A precursor material is superoxidized to a superconducting oxide material in an atmosphere containing a reactive component that reacts with and removes hydroxide ion (OH.sup.-), replacing it with peroxide ion (O.sup.-). Preferred reactive components include H.sub.2 O.sub.2, N.sub.2 O, and I.sub.2. The reactive component reacts with and removes hydroxide ion from the precursor material, to reach a higher oxidation state in the superconducting oxide material than possible by oxidation in molecular oxygen. The use of such a reactive component permits both faster oxidation of the precursor material at conventional temperatures and the use of lower temperatures to achieve oxidation.

Abstract: Powder of a ceramic superconducting material is synthesized such that each particle of the powder is a single crystal having a flake-like, nonsymmetric morphology such that the c-axis is aligned parallel to the short dimension of the flake. Nonflake powder is synthesized by the normal methods and is pressed into pellets or other shapes and fired for excessive times to produce a coarse grained structure. The fired products are then crushed and ground producing the flake-like powder particles which exhibit superconducting characteristics when aligned with the crystal lattice.

Abstract: High temperature superconducting oxide materials can be taken to a higher, but stable, state of oxidation by removing H-impurities, such as OH.sup.-, using I.sub.2 /O.sub.2 mixtures in a reactive atmosphere process. A higher T.sub.c and a narrower .DELTA.T-transition result.

Abstract: Novel superconductive oxides are disclosed. The oxides all have layered perovskite-like crystal structure and manifest superconductivity above about 77K. An exemplary material has composition Bi.sub.2.2 Sr.sub.2 Ca.sub.0.8 Cu.sub.2 O.sub.8. Other materials are described by the nominal formula X.sub.2+x M.sub.n-x Cu.sub.n-1 O.sub.2+2n+x/2.+-..delta., where X typically is Bi, or Bi together with Pb or other appropriate substituent, M is one or more divalent ion or mixture of monovalent and trivalent ion, n is an integer greater than 3, x=p/q, where p and q are integers and p<q, and .delta. is less than 0.5. Associated with the inventive compounds typically is a superlattice structure, with T.sub.c of the compound typically being correlated with the superlattice spacing. The inventive compounds are typically relatively ductile.

Abstract: Superconducting oxide ceramics having a high density of superconducting current are formed without making use of very high temperatures higher than 1000.degree. C. Superconducting oxide material is placed in a crucible, melted and fired at a relatively low temperature. During the melting and firing step, the partial pressure of oxygen is reduced in order to lower the melting point of the ceramic. After the firing, the partial pressure of oxygen is increased.

Abstract: A process for producing a superconducting material comprising a compound oxide represented by the general formula:(Ba, Ca).sub.x (.alpha., Dy).sub.1-x Tl.sub.y Cu.sub.1-y O.sub.3-zwherein ".alpha." represents Y or La; the atomic ratio of Ca to Ba is between 1% and 90%; the atomic ratio of Dy to .alpha. is between 1% and 90%; x, y and z are within the ranges of 0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1, and 0.ltoreq.z<1 respectively; and the expression of (Ba, Ca) and (.alpha., Dy) means that the respective elements occupy predetermined sites in a crystal in a predetermined proportion. The process comprises preparing a material powder, compacting the material powder and then subjecting the resulting compact to a final sintering operation and is characterized in that the material powder is(A) a powder mixture composed of powders selected from a group comprising (i) powders of elemental Ba, Cu, Ca, .alpha., Dy and Tl and (ii) powders of compounds each containing at least one of said elements Ba, Cu, Ca, .

Abstract: A method of producing a new high Tc superconducting material using fullerene molecules as artificial pinning sites for any magnetic flux that may enter the material.

Abstract: An improved technique for the fabrication of thallium-based superconducting oxides, and particularly Tl:Ba:Ca:Cu:O 2223 oxides, is described which allows production of very pure superconductors (>95% 2223 phase) having excellent structural characteristics. The method of the invention involves first forming a self-sustaining body of starting oxides and subjecting this body to a sintering technique wherein the temperature of the body is gradually raised to a maximum level of about 850.degree.-930.degree. C., followed by maintaining the body at this temperature for a period of about 48 hours. The body is then slowly cooled to avoid distortion and loss of superconducting character. Most preferably, the sintering is a two-stage operation, wherein the body is first heated a relatively low rate (e.g., 1.degree.-10.degree. C./min.) to a temperature of about 650.degree.-750.degree. C., followed by faster heating at a higher rate to achieve the maximum sintering temperature.

Abstract: An oxide superconducting material having a composition represented by a formulaTlSr.sub.2 (Sr.sub.n-x Y.sub.x)Cu.sub.n+1 O.sub.5+2nwherein n=1 or 2 and 0.1.ltoreq.x.ltoreq.n is provided. This material has a high critical current density Jc even by sintering at a relatively low temperature of 850.degree.-880.degree. C.

Abstract: A high-temperature oxide superconductor is provided and comprises oxide crystals oriented in a certain direction, the oxide superconductor being substantially free of or containing a controlled amount of foreign phases, a non-superconducting phase and weak superconducting phase which are harmful for superconducting characteristics in the grains of the crystals and at the grain boundaries between the crystals. The foreign phases, if any, are finely and uniformly dispersed in the grains of the oxide crystals and at the grain boundaries. A wire made from the oxide superconductor, a coil from the wire, and a magnetic field generator from the coil are disclosed, the superconductor wire having only a single layer of oxide crystal grains in the thickness direction.

Abstract: A superconducting ceramic composition which is free of thallium, the composition having a unit cell containing two perovskite structure copper-oxygen planes and a rocksalt structure layer having a single plane containing cadmium.

Abstract: According to the present invention, when a superconductive thin film is formed on a substrate of a single crystal, a compound having a composition of SrNdGaO.sub.4 and a K.sub.2 NiF.sub.4 type crystal structure is used as a material employable for the substrate. Alternatively, a single crystal composed of an oxide in which Ca, La and Cr are added to the foregoing compound is used as a material employable for the substrate. Then, a superconductive thin film composed of an oxide is formed on the substrate by employing an epitaxial growing method. Thus, the present invention makes it possible to provide a superconductive material having an excellent property of lattice alignment, a stable and high critical superconductivity temperature and a stable critical superconductivity electric current.

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: A method is provided for the high yield production of white, electrically conductive zinc oxide which comprises the simultaneous addition to a reactor of (1) an aqueous solution containing a water-soluble zinc compound and at least one water-soluble compound of a metal selected from the group consisting of tin, aluminum, gallium and indium, and (2) an aqueous alkaline solution, while maintaining the resulting neutralization reaction solution at a pH from 6 to 12.5 to obtain coprecipitates, and then calcining the coprecipitates in a reducing atmosphere to obtain said conductive zinc oxide.

Abstract: The present invention relates to an oxide superconductor comprising a composite oxide of RE , Ba and Cu, wherein the superconductor comprises a micro structure comprised of a monocrystalline REBa.sub.2 Cu.sub.3 O.sub.7-x phase (123 phase) and a RE.sub.2 BaCuO.sub.5 phase (211 phase) finely dispersed therein, the 123 phase being formed in a plurality of domains respectively for individual RE compositions and in the order of the 123 phase forming temperatures in respective layers.

Abstract: A method is disclosed for fabricating bulk superconducting materials into shaped articles, including ones of relatively large sizes and complex shapes, which have high densities, high integrity, high magnetization and critical current densities. A mixture of superconducting material is completely or substantially melted and the molten material is then cooled to room temperature and ground to a powder. The ground powder is next mixed with a second phase made up of either precursor superconducting powder or a mixture of metallic silver and copper. The resulting mixture is then shaped into an article by conventional ceramic article forming techniques: pressing, extruding, molding or the like. The resulting shaped article is heated to a temperature at which a substantial amount of its content of second phase material is melted, thus facilitating densification of the entire shaped article. The resulting dense specimen is annealed in an appropriate environment while it is being cooled to room temperature.

Abstract: A superconductor material having a current density, J, of from about 30,000 to about 85,000 amps/cm.sup.2 at zero magnetic field and 77.degree. K. is disclosed. The 123 superconductor, of the formula L.sub.1 Ba.sub.2 Cu.sub.3 O.sub.6 +.delta. wherein L is preferably yttrium, is capable of entrapping sufficiently high magnetic fields and exhibits a low microwave surface resistance. The process of preparing the superconductor comprises compacting the bulk product, L.sub.1 Ba.sub.2 Cu.sub.3 O, and then sintering the reaction product at a temperature between about 40.degree. C. to about 90.degree. C. below its melting point, i.e., for Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.6 +.delta. at a temperature of approximately 940.degree. C. The composition is then heated in a preheated chamber maintained at approximately 1090.degree. C. to about 1,200.degree. C. (approximately 1,100.degree. C. for Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.6 +.delta.

Abstract: A method of producing a superconductor of metal oxides having the following composition:(M.sub.1-x Ca.sub.x)(Ba.sub.1-y Sr.sub.y).sub.2 Cu.sub.4 O.sub.8wherein M stands for a rare earth element, x is 0 or a positive number of less than 1 and y is 0 or a positive number of less than 1, is disclosed, which includes hydrdolyzing an organic solvent solution or dispersion containing (a) alkoxide or fine particulate of a hydroxide of the rare earth element M, (b) alkoxides orfine particulate of hydroxides of Ca, Ba and Sr and (c) alkoxide, nitrate or fine particulate of hydroxide of copper in presence of water and nitrate ions. The alkoxides or hydroxides of Ca and Sr are present only when x and y are not zero, respectively. The hydrolyzed product is then dried, shaped and pyrolyzed to obtain the superconductor.

Abstract: A high-temperature superconducting system comprising M-Tl-Ba-Cu-O wherein: M is selected from the group consisting of Ti, Zr, and Hf. In one embodiment, the M-Tl-Ba-Cu-O system forms a high Tc phase of approximately 90 K wherein: M is selected from the group consisting of Zr and Hf. In another embodiment, a nominal ZrTl.sub.2 Ba.sub.2 Cu.sub.3 O.sub.10 sample forms a high Tc phase of above 100 K.

Abstract: A method is provided for preparing a precursor of a superconductor containing atoms of oxygen, atoms of copper and atoms of at least two other metals and sufficient atoms of oxygen so that up to, but no more than, one atom of copper is in the trivalent state, in which method there are blended together, in finely divided particulate state, components containing atoms of the metals in the desired proportion with at least one of the components containing oxygen in an amount above that which would put more than one atom of copper into the trivalent state and thereafter milling the components together in a high energy system to a maximum particle size of about 5 microns for at least 99 weight percent of the blend.