Abstract: An oxide superconductor which has a composition expressed by the following general formula and whose crystal structure is 1222-phase structure.Pb.sub.a (M.sub.1-x-y Ce.sub.x Sr.sub.y).sub.4 Cu.sub.3-a O.sub.z (I)(where M represents at least one element selected from the group consisting of Y, La, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, and Lu, and a, x, y, and z denote the numbers which satisfy 0.3.ltoreq.a.ltoreq.0.7, 0<x.ltoreq.0.25, 0.3.ltoreq.y<0.5, 8.5.ltoreq.z.ltoreq.9.5, respectively). A Pb-based Cu oxide superconductor manufacturing method comprising the steps of mixing powders of raw materials containing at least Pb, Sr, Ce, M (where M represents at least one element selected from the group consisting of Y, La, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, and Lu groups) and Cu in the proportion to have the composition shown in the general formula (I) above, optionally forming the mixed powder into a shape body, and firing the obtained powder mixture or the shape body in the temperature range of 900.degree.

Abstract: The invention relates to an oxide-ceramic superconducting material which contains bismuth, strontium, calcium and copper, having an overall composition of Bi.sub.y Ca.sub.2 Sr.sub.2 Cu.sub.3 O.sub.x, where y is an integer from 2.35 to 2.6 and x is about 10 to 12. The material has a critical temperature T above 105 K and has a proportion of the phase Bi.sub.2 Sr.sub.2 Ca.sub.2 Cu.sub.3 O.sub.x of at least 85% by volume. The invention also relates to a process for producing a bismuth-containing superconducting material which comprises holding the oxides or oxide precursors of bismuth, strontium, calcium and copper at a temperature in the range from 850.degree. to 890.degree. C. over a time span of a plurality of hours and adhering to the following atomic ratios:Bi:Cu>2:3Ca:Sr=0.9 to 1.50.SIGMA.(Sr+Ca):Cu=4.2:3 to 4:3.33Bi:.SIGMA.(Sr+Ca)=2.35:4 to 3.

Abstract: A now 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; andthe expression of (Ba, Ca) and (.alpha., Dy) mean that the respective elements occupy predetermined sites in a crystal in a predetermined proportion.

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: An oxide superconductor having a structure such that a double oxide of at least one metal selected from the Group 2A elements and at least one metal selected from the Group 4A, Group 4B and rare earth elements, is dispersed in oxide superconductor crystals.

Abstract: According to the present invention, when a super-conductive 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 super-conductive 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 super-conductive material having an excellent property of lattice alignment, a stable and high critical superconductivity temperature and a stable critical superconductivity electric current.

Abstract: The invention relates to a process for producing a bismuth-, copper-, strontium- and calcium-containing high-temperature superconductor, in which an aqueous solution is produced which has a pH of 0.5-4 and which contains the metals in an atomic ratio corresponding to a high-temperature superconductor, the solution is combined with an oxalic acid solution to precipitate the metals quantitatively as oxalates, the oxalates formed are separated off and decomposed thermally to form the oxides and the latter are reacted in the presence of oxygen at temperatures above 700.degree. C. to form the desired high-temperature superconductor. The process comprises concentrating the aqueous solution of the metal until a precipitate begins to appear and using the oxalic acid as a solution in an organic solvent which is miscible with water The oxalates are decomposed at 550-700.degree. C. in the presence of oxygen.

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.l+y+(3/2)x, with a face-centered tetragonal crystalline structure of perovskite type. When being cooled at 85-135K, the structure of the substance starts to transform and its electric resistance disappears at a temperature higher than 47K so that the substance becomes superconductive.

Abstract: An oxide superconductor of the formula: Bi.sub.1.0 Sr.sub.A Ca.sub.B Mg.sub.C Ba.sub.D Cu.sub.1.0.+-.0.15 O.sub.X wherein A=0.6-1.3, B=0.3-0.9, C=0.01-0.3 and D=0.01-0.3 in atomic ratio, having a 2212 phase with a critical temperature of making electrical resistance zero at about 80K or more, can be produced by firing preferably at 820.degree.-870.degree. C. in a lower oxygen content atmosphere.

Abstract: Disclosed herein is a method of preparing a bismuth oxide superconductor by forming a superconducting phase having a 2223 composition or a 2212 composition in a composition of Bi-Sr-Ca-Cu or (Bi,Pb)-Sr-Ca-Cu in a metal sheath. This method comprises the steps of preparing raw material powder containing a mixture of a 2212 phase having the 2212 composition and non-superconducting phases, carrying out a process of heat treating the raw material powder under a reduced pressure of not more than 1 atm. immediately before filling the same into the metal sheath and thereafter cooling the same under an oxygen atmosphere, and filling the raw material powder into the metal sheath and thereafter performing deformation processing and heat treatment on the metal sheath. This method is suitable for preparation of a long wire.

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: 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: 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: Solutions containing the cations of the metals Y, Ba, Cu in the atomic ratio 1:2:3 or the cations of the metals Bi, Sr, Ca and Cu having the atomic ratios of a high-temperature superconductor bound to polyacrylic acid in water as dispersant and having a viscosity of 150-10,000 cSt (at 20.degree. C.) serve to produce superconducting filaments or coatings.To produce a superconducting filament, a solution is forced through a nozzle and the extruded filamentous strand is left to solidify in an organic solvent which is miscible with water, the filament is isolated, dried and heated to at least 800.degree. C. in the presence of oxygen, annealed at at least 800.degree. C. for at least one hour in the presence of oxygen and then cooled.

Abstract: A novel method for forming homogeneous silver high temperature superconductor (HTS) composites. The novel method comprises a chemical coprecipitation of silver, barium, yttrium, and copper salts solutions, followed by calcination and milling processes. The novel method has an advantage of retaining all the virtues immanent in a composite HTS, for example, increased critical current density (Jc), and improved mechanical properties, while bypassing extant and deficient methodologies for forming a composite, the deficient composites characterized by heterogeneity.

Abstract: The invention relates to a weather-resistant, pearlescent pigment which comprises mica flakes coated with a metal oxide as base material, (a) hydrated zirconium oxide formed by hydrolysis of a zirconyl compound in the presence of a hypophosphite, and (b) a hydrated metal oxide (or oxides) formed by hydrolysis of a water-soluble compound (or compounds) of at least one member selected from the group consisting of cobalt, manganese and cerium, said components (a) and (b) being deposited on the surface of said base material.

Abstract: The invention relates to a process and an apparatus for converting metal nitrate or mixed metal nitrate solutions into the corresponding metal oxides in a microwave field. The invention consists in heating, while the feed stream is being metered in, in such a manner that the solvent always evaporates within seconds and the decomposition product is obtained as a porous, sponge-like, purely oxidic material, which can be ground easily to give a powder having particle sizes of 0.5 to about 10 .mu.m. The controlled metering in of the nitrate solution simultaneously makes it possible to control the reaction temperature below the sintering temperature of the powder. The reaction of the nitrate starting solution can take place continuously/batchwise in a reaction flask or continuously in a rotating reaction pipe, which is preferably charged with grinding balls, which possibly exert a reaction-activating effect similar to that exerted very particularly by the metal oxide sponge formed during the reaction.

Abstract: Compositions containing a crystalline phase of the formula Tl.sub.2 Ba.sub.2 CuO.sub.6+x wherein x is from 0 to 0.5. Processes for manufacturing such compositions and for using them are 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: A dental material for the control of caries and paradentitis is described, which contains an active agent combination of thymol and/or carvacrol and chlorhexidine and/or the physiologically compatible salts thereof.The dental material can be a dental varnish or a material such as a dental cement and the like, which remains in the oral cavity for a long period and from which the active combination can diffuse out.