Abstract: A process for obtaining precursors for high critical temperature superconductor ceramics by precipitating salts which are insoluble in water comprises the following stages: A starting solution of soluble salts is prepared in which the cations are in the stoichiometric proportions of the required superconductor phase. A first full precipitation is carried out of a first series of cations at a first value of pH. The first precipitates obtained is filtered out and washed and the filtrate is retained. The pH of the filtrate is changed to a second value and the residual cations are precipitated. The second precipitate is filtered. The first and second precipitates are homogenized. The product obtained is dried, calcined, and ground.

Abstract: A method for making a high critical current density Bi.sub.2 CaSr.sub.2 Cu.sub.2 O.sub.8 superconductor includes mixing suitable solid state reactants in amounts sufficient to create a reactant mixture having a ratio of approximately 4 Bi atoms:3 Ca atoms:3 Sr atoms:4 Cu atoms and oxygen. The reactant mixture is heated to a sufficient temperature for a sufficient time to sinter the reactant mixture and form a Bi.sub.2 CaSr.sub.2 Cu.sub.2 O.sub.8 superconductor.

Abstract: The present invention provides an oxide superconductor which is mainly composed of bismuth, lead, strontium, calcium, magnesium, and copper and has the composition represented by the formula:Bi.sub.1-A Pb.sub.A Sr.sub.1-B Mg.sub.B Ca.sub.1 Cu.sub.1.7.+-.0.3 Oxwherein A=0.15-0.35 and B=0.05-0.3 in which numerals represent atomic ratio and an oxide superconductor which is mainly composed of bismuth, lead, strontium, calcium, magnesium, barium and copper and has the composition represented by the formula:Bi.sub.1-A Pb.sub.A Sr.sub.1-(B+C) (Mg.sub.B Ba.sub.C)Ca.sub.1 Cu.sub.1.7.+-.0.3 Oxwherein A=0.15-0.35, B=0.05-0.3 and C=0.02-0.2 in which numerals represent atomic ratio. Methods for producing these superconductors are also provided.

Abstract: A method of preparing a superconducting oxide by combining the metallic elements of the oxide to form an alloy, followed by oxidation of the alloy to form the oxide. Superconducting oxide-metal composites are prepared in which a noble metal phase intimately mixed with the oxide phase results in improved mechanical properties. The superconducting oxides and oxide-metal composites are provided in a variety of useful forms.

Abstract: A now superconducting material comprising a compound oxide represented by the general formula:(Sr,.gamma.).sub.x (La,.delta.).sub.1-x .epsilon..sub.y Cu.sub.1-y O.sub.3-zin which".gamma." represents an element of IIa group of the periodic table except Sr, an atomic ratio of .gamma. to Sr being selected in a range between 1% and 90%,".delta." represents an element of IIIa group of the periodic except La, an atomic ratio of .delta. to La is selected in a range between 1% and 90%,".epsilon." represents a metal element of Vb group of the periodic table, x, y and z are numbers each satisfies ranges of 0.ltoreq.x.ltoreq.1,0.ltoreq.y.ltoreq.1, and 0.ltoreq.z.ltoreq.1 respectively, and the expression of (Sr,.gamma.) and (La,.delta.) mean that the respective elements position predetermined sites in a crystal in a predetermined proportion.

Abstract: Oxide materials of (L.sub.x A.sub.1-x).sub.i MO.sub.y, (L.sub.x A.sub.1-x).sub.i M.sub.1-z Cu.sub.z O.sub.y and (L.sub.x A.sub.1-x).sub.i MO.sub.j-.delta. G.sub.k, wherein L is Sc, Y, lanthanides, etc.; A is Ba, Sr. Ca, etc.; M is V, Nb, Ta, T, Zr or Hf; 0<x<1; 0<z<1; i=1, 3/2 or 2; 0<y.ltoreq.4; Gis F, Cl or N; .delta. is oxygen defect, and having a perovskite-like crystal structure, show superconductivity at a temperature higher than the liquid nitrogen temperature.

Abstract: A piezoresistive pressure transducer employing a sapphire force collector diaphragm having piezoresistive films of silicon epitaxially formed on a major surface thereof, preferably in a Wheatstone bridge pattern. The silicon piezoresistive film is preferably of a thickness of from 1,000 to 60,000 angstroms and is doped with boron in the range of from 5.times.10.sup.17 to 9.times.10.sup.20 atoms/cc. Electrical lead traces and electrical contact pads are also formed on the major surface of the force collector diaphragm. The diaphragm is mounted on a pressure cell base having a cavity in the upper surface thereof, the diaphragm enclosing the cavity so as to form a chamber with the piezoresistive silicon films within said chamber. The diaphragm is hermetically bonded by a ceramic glass to the base in a vacuum such that the chamber provides a vacuum pressure reference.

Abstract: A superconductor consisting of a sufficiently pure phase of the oxides of Bi, Sr, Ca, and Cu to exhibit a resistive zero near 110K resulting from the process of forming a mixture of Bi.sub.2 O.sub.3, SrCO.sub.3, CaCO.sub.3 and CuO into aparticulate compact wherein the atom ratios are Bi.sub.2, Sr.sub.1.2-2.2, Ca.sub.1.8-2.4, Cu.sub.3. Thereafter, heating the particulate compact rapidly in the presence of oxygen to an elevated temperature near the melting point of the oxides to form a sintered compact, and then maintaining the sintered compact at the elevated temperature for a prolonged period of time. The sintered compact is cooled and reground. Thereafter, the reground particulate material is compacted and heated in the presence of oxygen to an elevated temperature near the melting point of the oxide and maintained at the elevated temperature for a time sufficient to provide a sufficiently pure phase to exhibit a resistive zero near 110K.

Abstract: A Bi-Pb-Sr-Ba-Ca-Cu-O system superconductor having a composition of:Bi.sub.l Pb.sub.m Sr.sub.p Ba.sub.q Ca.sub.y Cu.sub.z O.sub.xwherein l, m, p, q, y and z satisfy the following inequalities:0.50<l<1.500.01.ltoreq.m.ltoreq.0.600.70.ltoreq.p.ltoreq.1.600.005.ltoreq.q.ltoreq.0.800.70.ltoreq.y.ltoreq.1.601.40.ltoreq.z.ltoreq.3.00which has the critical temperature of at least 77 K, and contains the high T.sub.c phase in a high fraction.

Abstract: A high temperature superconductor having the formula Tl-Sr-Ca-Cu-O and a transition temperature about 70 K (with some evidence of a 100 K phase) is provided. Processes for making high temperature superconductors are also provided.

Abstract: Bulk form of superconducting materials are produced by pouring a melt a O.sub.2 -containing superconducting material into a heated mold, cooling the mold until solidification begins, removing the cast object from the mold, gradually cooling the cast object to prevent the development of thermal stresses, and then annealing the cast, cooled object to restore O.sub.2 to near equilibrium levels. The bulk form produced according to the present invention may be used as a sputtering target in the production of wires, or as a bulk form semiconductor.

Abstract: A superconducting oxide composition comprising Ln-Th-Cu-O wherein Ln indicates at least one element selected from a group consisting of Pr, Nd, Pm, Sm, Eu, Gd and Er. A superconducting structure is formed in such a manner that at least an insulating layer is sandwiched between two superconductor layers but the superconductor layers are electrically coupled with each other, and a superconducting device including the superconducting structure is constructed so as to perform a switching operation for an electric signal, to detect a light signal, and to detect the intensity of a magnetic field. Another superconducting device is formed so that two superconductor layers are put in direct contact with each other, and a tunnel current between the superconductor layers can be controlled.

Abstract: A process for preparing a superconductor-coated substrate including calcining a mixture of powdered yttrium or rare earth oxide (R), barium carbonate and copper oxide in a controlled atmosphere and in accordance with a predetermined temperature profile to form a superconductor powder having a stoichiometric ratio of R-Ba-Cu of approximately 1-2-3. The melting transition width of the resulting powder is relatively narrow, such that the melting onset temperature is above the high temperatures advantageously used to sinter the powder on the substrate.

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 new high temperature superconducting system with transition temperature above 120 K is disclosed. One superconductor in that system in a preferred embodiment comprises TlRBaCuO wherein R is chosen from Group 2A elements excluding Ba. In a preferred embodiment, the superconductor is TlCaBaCuO. In another preferred embodiment, the superconductor comprises TlSrCuO. Processes for making high temperature superconducting system are also disclosed.

Abstract: The disclosed superconducting oxide material has a crystal structure of either Nd.sub.2 CuO.sub.4 type or oxygen-deficient perovskite type and mainly consists of a composition having a general chemical formula of (R.sub.1-x A.sub.x).sub.m+1 Cu.sub.m O.sub.3m+1-y, R being at least one rare earth element selected from the group consisting of Pr, Nd, Sm, Eu, Gd, Dy, Tb, Ho, Er, Tm, Yb, and Lu, A being Ce or Th, m being an integer of 1, 2, 3, . . . .infin. (m=.infin. standing for (R.sub.1-x A.sub.x)CuO.sub.3-y), 0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.m, Cu in the material having an average valence of not larger than +2 for all R, A, m, x, and y.The disclosed superconducting oxide material may have a general chemical formula of Nd.sub.2-x-z Ce.sub.x Sr.sub.z CuO.sub.4-y, 0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1, and 0.ltoreq.z.ltoreq.1.The above superconducting oxide material can be made by mixing powdery starting materials for the composition, sintering the mixture at 1,000.degree. to 1,100.degree. C.

Abstract: The disclosed substance has a general chemical formula of Y.sub.3-x --Ba.sub.x Cu.sub.y --O.sub.z, x being 0 to 1, y being 3 to 6, and z being 6 to 12. At a temperature below 90.degree.-95.degree. K., the disclosed substance shows superconductive photoconductivity or even both superconductivity, either real or potential, and photoconductivity in response to incident exciting light in a wavelength range of 420 to 640 nm. The substance is produced by heating a mixture of starting material therefor at 750.degree.-1,050.degree. C. for 1-10 hours so as to cause solid phase reaction, cooling gradually, shaping under pressure, sintering at 670.degree.-1,050.degree. C., and cooling either quickly at a rate of 2,000.degree.-900.degree. C./sec or slowly at a rate of 150.degree.-200.degree. C./hour.

Abstract: Compositions having the nominal formula Bi.sub.2 Sr.sub.3-x Y.sub.x Cu.sub.2 O.sub.8+y wherein x is from about 0.05 to about 0.45 and y is from about 0 to about 1 are superconducting.

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: A new pigment mixture consisting of 40-80% by weight calcium carbonate and/or dolomite and 20-60% by weight talc or 20-60% of a talc-kaolin mixture or 20-60% by weight of a talc-mica mixture gives substantial improvements in the use in the paper industry, in particular in the production of lightweight coated rotogravure papers.