Abstract: An oxygen excess type metal oxide expressed with the following formula (1) and exhibiting high speed reversible oxygen diffusibility whereby a large amount of excess oxygen is diffused at a high speed and reversibly in a low temperature region: AjBkCmDnO7+???(1) where A: one or more trivalent rare earth ions and Ca B: one or more alkaline earth metals C, D: one or more oxygen tetra-coordinated cations among which at least one is a transition metal, where j>0, k>0, and, independently, m?0, n?0, and j+k+m+n=6, and 0<??1.5.

Abstract: A nitrogen oxide detecting sensor, according to the present invention, incorporates a gas detecting portion including, as a main component thereof, an oxide compound having electric conductivity or semiconductivity, the oxide compound having a crystal structure of 2212 phase and expressed generally as: Bi.sub.2 Sr.sub.2 (Ca.sub.1-x Y.sub.x)Cu.sub.2 O.sub.8.+-..delta. where 0.6.ltoreq.x<1; 0.ltoreq..delta..ltoreq.1. Electrodes are electrically connected to the gas detecting portion. When the gas detecting portion is analyzed by X-ray diffraction using cuK.alpha. rays to obtain diffraction peak values thereof in the range of a diffraction angle between 5.degree. and 65.degree., the diffraction peak values having a sum .SIGMA. I?2212! expressed by one of the following:(a) .SIGMA. I?2212!/.SIGMA. I?T!>88.1%(b) {.SIGMA. I?2212!+.SIGMA. I?2201!}/.SIGMA. I?T!>94.8%(c) {.SIGMA. I?2212!+.SIGMA. I?Y.sub.2 O.sub.3 !} .SIGMA. I?T!>88.1%(d) {.SIGMA. I?2212!+.SIGMA. I?(Bi, Ca) O!}/.SIGMA. I?T! >88.8%where .

Abstract: In order to provide a Tl--Ba--Ca--Cu--O superconductive material which can obtain a stable superconducting state and a method of preparing the same, the oxide superconductive material is expressed in the following composition formula:Tl.sub.x Ba.sub.2 Ca.sub.y Cu.sub.3 O.sub.zwhere x, y and z are in relations satisfying 1.5.ltoreq.x.ltoreq.2.0, 2.0.ltoreq.y.ltoreq.2.5, x+y=4.0 and 9.0.ltoreq.z.ltoreq.11.0, and comprises tetragonal system superconducting phases having lattice constants of a=0.385 to 0.386 nm and c longer than 3.575 nm, to exhibit zero resistance under a temperature of at least 125 K, while the method comprises a step of mixing powder raw materials in blending ratios for satisfying the above composition formula, a step of sintering the as-formed mixed powder in an oxygen jet or in the atmosphere to obtain a sintered body, and a step of annealing the sintered body in a closed atmosphere at 700.degree. to 800.degree. C. for at least 10 hours.

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: 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 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: A method of manufacturing an oxide superconductor, including the steps of mixing oxide materials of the metals contained in an oxide superconductor represented by HgBa.sub.2 Ca.sub.2 Cu.sub.3 O.sub.8+y to prepare a powder mixture of the composition noted above, molding the powder mixture to prepare a molded body of a desired shape, and applying a heat treatment to the molded body within a hermetic container at a temperature sufficient for bringing about a solid phase reaction of the oxide materials for at least 20 hours.

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: 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: 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 secbutoxy 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: 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: 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: Disclosed herein are high-temperature oxide superconductors of RBa.sub.2 Cu.sub.4 O.sub.8 type, with Ba partly replaced by Sr or Ca, or with R and Ba partly replaced by Ca and Sr, respectively, as represented by the chemical composition formula of R(Ba.sub.1-y Sr.sub.y).sub.2 Cu.sub.4 O.sub.8 or R(Ba.sub.1-z Ca.sub.z).sub.2 Cu.sub.4 O.sub.8 or (R.sub.1-x Ca.sub.x) (Ba.sub.1-y Sr.sub.y).sub.2 Cu.sub.4 O.sub.8. They exhibit superconductivity at high temperatures. Especially, the last one exhibits superconductivity at a higher temperature than the former two. All of them can be made with a less amount of Ba as a deleterious substance, and the first two have improved sinterability. The best results are obtained when they are produced by the process involving the hot hydrostatic pressure treatment of the mixture of raw materials at 850.degree.-1100.degree. C. in an atmosphere composed of an inert gas and oxygen. The process permits a wider selection of Ba raw materials.

Abstract: Disclosed is a method of manufacturing a thin film of an oxide superconductor represented by formula Sr.sub.1-x Nd.sub.x CuO.sub.2 on a substrate. The oxide superconductor has a tetragonal crystal structure, the lattice constant in a-axis falling within a range of between 0.385 nm and 0.410 nm, and the lattice constant in c-axis being an integer number of times as much as a level falling within a range of between 0.310 nm and 0.350 nm. The method includes the steps of forming by epitaxial growth a film of a crystal having lattice constants close to those of the crystal of said oxide superconductor on a substrate, and forming a thin film of the oxide superconductor of a tetragonal crystal structure represented by general formula (I) by a thin film-forming technique.

Abstract: A superconductive oxide material having an infinite layer structure and having the following formula:A.sub.p B.sub.q Cu.sub.2 O.sub.4.+-.rwherein A and B are different and each represent an element selected from lanthanoid elements and elements belonging to Groups IA, IIA and IIIA of the Periodic Table, p is between 0.9 and 1.1, q is between 0.9 and 1.1 and r is between 0 and 0.6. The oxide material has a crystal structure belonging to a tetragonal system of P4/mmm and 1-123 having the following lattice parameters:3.8.ANG..ltoreq.a.ltoreq.4.0.ANG.7.6.ANG..ltoreq.c.ltoreq.8.0.ANG.or to an orthorhombic system of Pmmm and I-47 having the following lattice parmeters:3.8.ANG..ltoreq.a.ltoreq.3.95.ANG.3.82.ANG..ltoreq.b.ltoreq.4.0.ANG.7.6.ANG..ltoreq.c.ltoreq.8.0.ANG..

Abstract: The oxide superconductor according to the present invention is represented by (Hg.sub.1-x Pb.sub.x)Ba.sub.2 Ca.sub.2 Cu.sub.3 O.sub..delta. (0.08.ltoreq.x.ltoreq.0.41, 7.625.ltoreq..delta..ltoreq.9.15), and has a crystal structure in which a lamination unit of (Hg, Pb)O.sub.z -BaO-CuO.sub.2 -Ca-CuO.sub.2 -Ca-CuO.sub.2 -BaO is laminated in a c-axial direction of the crystal structure (0.625.ltoreq.z.ltoreq.2.15). Further, the method of manufacturing an oxide superconductor, according to the present invention, includes the steps of: mixing material powders of HgO, PbO, BaO, CaO and CuO at a mole ratio of (Hg.sub.1-x Pb.sub.x):Ba:Ca:Cu=a:2:b:c (1.ltoreq.a.ltoreq.2.5, 2.ltoreq.b.ltoreq.3, 2.5.ltoreq.c.ltoreq.4) and compression-molding the mixture powder into a compact; and subjecting the compact to a thermal treatment at 600.degree.-750.degree. C.

Abstract: A method for manufacturing a Pb-based Cu oxide superconductor. The method includes the steps of mixing powders of a raw material containing at least Pb, Sr, Ce, M, where M is at least one element selected from the group consisting of Y, La, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, and Lu, and Cu in a proportion to have the composition of the formula (I),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 is 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, forming the mixed powder into a shaped body, and firing the shaped body at a temperature of 900.degree. to 1150.degree. C. in an oxidizing atmosphere.

Abstract: Disclosed is a boride material for electronic elements, which is represented by a chemical formula of A.sub.1-x E.sub.x B.sub.12 (where A is Zr of Hf, E is Sc or Y, and 0.1.ltoreq.x.ltoreq.0.9) and the crystal system of which is a cubic one at a temperature not lower than its phase transition temperature and is a hexagonal one at a temperature not higher than its phase transition temperature. The boride material is prepared by mixing oxide powders or sulfate powders of the constitutive elements A and E and a boron powder followed by shaping the powder mixture and then sintering the shaped body.