Abstract: A alloy (Mg—X) of metal (X) and Mg in a liquid phase is made to react with B in a solid phase at a low temperature to manufacture a superconductor, which contains a large amount of MgB2 potential for MRI, linear motorcar, superconducting cavity, electric power transmission cable, high-magnetic field magnet for medical units, electric power storage (SMES), and the like and is formed in the shape of bulk, wire, and foil, by heat treatment performed at a low temperature for a short time and at low cost.

Abstract: A precursor is made from a plurality of materials having different vapor pressures. The precursor and a source material are placed in a closed heat treatment furnace. The source material is materials which are the same as some of the materials contained in the precursor and having particular vapor pressures. The precursor and source material is thermally treated in the furnace while the source material is being supplied, so the particular materials in the precursor have their evaporation suppressed, thereby forming compounds. The compounds may be oxide superconductors, oxide dielectric, and so on.

Abstract: A metal oxide is provided which is represented by the compositional formula :(Bi.sub.1-x A.sup.I.sub.x).sub.2 (Sr.sub.y Ca.sub.1-y-z A.sup.II.sub.z).sub.p (Cu.sub.1-r A.sup.III.sub.r).sub.q O.sub..delta.wherein 0.ltoreq.x.ltoreq.0.5, 0.3.ltoreq.y.ltoreq.0.7, 0.ltoreq.z.ltoreq.0.5, 0.ltoreq.r.ltoreq.0.1, 1>y+z, 2>p>11, 1.ltoreq.q.ltoreq.10 and 5.4.ltoreq..delta..ltoreq.24 with the exclusion of x=z=r=0, A.sup.I is at least one element selected from In, Sb, Pb and Sn; A.sup.II is at least one element selected from Na, K, Mg, Ba, and Sn and A.sup.III is at least one element selected from Ti, V, Cu, Ni, Zr, Nb, Ta, Fe and Ru. The metal oxide may further comprise an element selected from lanthanoids and yttrium. The metal oxide material shows superconductivity at a temperature not lower than the boiling point of liquid helium.

Abstract: Superconducting oxide material containing compound represented by the formula:(Tl.sub.(l-p-q) Bi.sub.p Pb.sub.q).sub.y .gamma..sub.z (.alpha..sub.(l-r) .beta..sub.r).sub.s Cu.sub.v O.sub.win which each of ".alpha." and ".gamma." is an element selected in IIa group of the periodic table, ".beta." is an element selected from a group comprising Na, K, Rb and Cs, "y", "z", "v", "w", "p", "q", "r" and "s" are numbers each satisfying respective range of 0.5.ltoreq.y.ltoreq.3.0, 0.5.ltoreq.z.ltoreq.6.0, 1.0.ltoreq.v, 5.0.ltoreq.w, 0.ltoreq.p.ltoreq.1.0, 0.ltoreq.q.ltoreq.1.0, 0.ltoreq.r.ltoreq.1.0 and 0.5.ltoreq.s.ltoreq.3.0.

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: A substance which has a Cu--O plane containing crystal structure in its unit cell and which is called a Bi oxide superconductor consisting essentially of Bi, Sr, Ca, Cu, and O. Not only part of Bi but also part of Sr and/or Ca of the Bi oxide superconductor is substituted for Pb and rare earth elements (RE), respectively. The Pb substitution relaxes the structural modulation which is closely related to superconductivity of the Bi oxide superconductor and the RE substitution controls its carrier concentration. Accordingly, superconducting properties such as transition temperature and critical current density can be improved remarkably. In addition, not only oxide superconductors with excellent superconductivity can be prepared in a low oxygen content but also the surface condition of the prepared superconductors is stable.

Abstract: A super conducting material is disclosed which exhibits super conducting properties at higher temperatures than known so far. The super conducting by the invented materials is exhibited at temperatures of over 110.degree. K. Various combinations of the components exhibits superconductivities even at temperatures of around 273.degree. K. or even around 300.degree. K. Contrary to known art superconducting materials, which require super cooled conditions and are suited only to sophisticated applications, and thereby have limited applications, the materials of this inventions do not always require super cooled conditions are suited for limitless applications and can work even at room temperature conditions. While a large range of choice of materials are suggested a few important combinations are made of oxides of Bismuth, Barium and Copper. Replacement of Barium by Thallium gives additional advantages.

Abstract: Superconductors using oxide superconducting materials having pinning centers inside crystal grains are enhanced in transmissible critical current density and allowed to have a high critical current density even in the magnetic field. A superconductor is produced comprising superconducting materials having a high irreversible magnetic field where the c axes of their crystals are oriented in one direction. This can be practically realized by heat-treating a superconducting material having the composition (Tl.sub.1-X1-X2 Pb.sub.X1 Bi.sub.X2)(Sr.sub.1-X3 Ba.sub.X3).sub.2 Ca.sub.2 Cu.sub.3 O.sub.9+X4 together with Bi.sub.2 Sr.sub.2 CaCu.sub.2 O.sub.8 having a tendency of growing in the form of plate crystal. Various apparatuses capable of working under cooling with liquid nitrogen let alone with liquid helium and having a high superconducting critical current density even in a high magnetic field can be produced.

Abstract: A method for synthesizing ultrahomogeneous nanoparticles of precursor powder by coprecipitation in a water and oil microemulsion is disclosed. The powder is compressed and sintered to prepare an essentially pure 2223 superconductor.

Abstract: Superconducting materials and methods of forming superconducting materials are disclosed. Highly oxidized superconductors are heated at a relatively high temperature so as to release oxygen, which migrates out of the material, and form a non-superconducting phase which does not diffuse out of grains of the material. The material is then reoxidized at a lower temperature, leaving the non-superconducting inclusions inside a superconducting phase. The non-superconducting inclusions act as pinning centers in the superconductor, increasing the critical current thereof.

Abstract: A method for manufacturing the oxide superconductor according to the present invention comprises the steps of: mixing a starting material including Bi, Sr, Ca and Cu such that a mole ratio of Bi, Sr, Ca and Cu is 2:2+a:1+b:2+c, wherein a.gtoreq.0, b.gtoreq.0, c.gtoreq.0, and 0<a+b+c<3; melting the mixed material at a temperature of 900.degree. C.-1500.degree. C.; quenching rapidly the molten material; and annealing the quenched material at a partial molten temperature of 800.degree. C.-1000.degree. C. This method gives product wherein a precipitate of at least one compound in the group SrO, CuO and (Ca.sub.1-x Sr.sub.x).sub.2 CuO.sub.3 (wherein 0.gtoreq.x<1) is finely dispersed in the superconducting crystal of Bi.sub.2 Sr.sub.2 Ca.sub.1 Cu.sub.2 O.sub.y (wherein y is about 8). The precipitates act as flux pinning centers.

Abstract: The disclosed oxide has a general chemical formula of Ba-Pb.sub.1-x -Bi.sub.x -O.sub.z, x being 0.35 to 1 and z being 2.7 to 3, and the oxide shows a potential superconductivity at a temperature below 14K and a photoconductivity at a temperatures below 160K at least in an exciting wavelength range of 500 to 700 nm depending on the value of the above x.The oxide is made by heating a mixture of starting materials for the desired composition at 750-850.degree. C. for 2-10 hours so as to cause solid phase reaction in the mixture, cooling the heated materials gradually, shaping the cooled mixture under pressure, reheating the shaped materials at 500-850.degree. C. for 2-10 hours so as to effect secondary sintering thereon, keeping the reheated materials at 600-500.degree. C. for 2-3 hours and cooling the same either extremely quickly at a rate of 1500-900.degree. C./sec or slowly at a rate of 150-200.degree. C./hour.

Abstract: 1. In the (Bi,Tl)-Ca-(Sr,Ba)-Cu-O based superconducting ceramics production process, a process for preparing superconducting ceramics characterized by(a) providing powders includingi) a compound of Bi oxide or Tl oxide,ii) a Ca compound,iii) an Sr compound or Ba compound, andiv) a Cu compoundas starting powders;(b) compounding and mixing powders from compounds of the starting powders, the compounds each having lower vapor pressure, i.e., powders from compound ii), compound iii), and compound iv) at a compounding ratio to obtain a mixture, and primarily calcining the mixture at a temperature of 850.degree. to 1050.degree. C., to form a Ca--(Sr,Ba)--Cu--O based oxide; and(c) further mixing the Ca--(Sr,Ba)--Cu--O based oxide with a compound having a higher vapor pressure, that is, the powder of compound i), at a compounding ratio, and secondarily calcining at a temperature of 500.degree. to 820.degree. C.

Abstract: A novel process for preparing superconductor of bismuth-containing compound oxide such as Bi--Sr--Ca--Cu system.In the present invention, firstly an intermediate compound oxide containing metal elements of the superconductor except bismuth is prepared and then the intermediate compound oxide is contacted with bismuth oxide vapour at a temperature between 750.degree. and 950.degree. C. so that bismuth oxide is reacted with said intermediate compound oxide.

Abstract: A new class of Bi-based superconductive oxides is disclosed. As do the previously known Bi-based superconductors, the novel materials have a perovskite-like crystal structure. However, in contradistinction to the prior art materials, the inventive materials have unmixed B-site occupany, with all substituents occupying A-sites. This tends to produce marginal stability and enhanced transition temperatures, as compared to the prior art Bi-based oxide superconductors. Materials according to the invention have composition ABiO.sub.3-.delta., with A being Ba and at least one monovalent element (typically chosen from Na, K,Rb, and Cs) and 0.ltoreq..delta..ltorsim.0.1, and have a transition temperature T.sub.c.sup.onset .gtorsim.13K. The superconductive materials are advantageously produced from precursor material that contains an excess of the monovalent element(s), as compared to the final composition.