International Superconductivity Technology Center

Matsushita Electric Industrial Co., Ltd.

Sumitomo Electric Industries, Limited

Tohoku Electric Power Company, Inc.

The Furukawa Electric Co., Ltd.

Ube Industries, Inc.

Matsushita Electrical Industrial Co., Ltd.

Central Research Institute of Electric Power Industry

Tohoku Electric Power

Seiji Adachi

Shoji Tanaka

Hisao Yamauchi

Makoto Itoh

Ayako Yamamoto

Kazuyuki Isawa

Xiao-Jing Wu

Toshiyuki Tamura

Changqin Jin

Osamu Inoue

Nobuyuki Sugii

Takahiro Wada

Kazuyuki Hamada

Syunichiro Kawashima

Takeshi Sakurai

Tetsuyuki Kaneko

Michiharu Ichikawa

Toshihiro Mihara

Kouichi Kugimiya

Hirotsugu Takizawa

Yuji Yaegashi

Masahiko Shimada

Nobuo Mouri

Tadashi Tatsuki

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:

Method of preparing oxide superconductive material

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).

Rock-salt/infinite layer chlorine-containing oxide superconductor and

The present invention provides an oxide superconductor which is expressed in the composition formula

Oxide superconductor and method for manufacturing the same

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.

Oxide superconductor

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. under a super-high pressure of 20,000-80,000 atm.

Oxide superconductor and method of producing same

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. Also provided is a method of manufacturing an oxide superconductor, including the steps of mixing at least one additive element selected from the group consisting of Pb, Bi, Tl, Au, Pt, Ag, Cd and In with oxide materials of the metals contained in a Hg-series 1223 type oxide superconductor to prepare a powder mixture, 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 10 hours.

Method of manufacturing oxide superconductor

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.

(Hg Cu)Bg.sub.2 Ca.sub.2 Cu.sub.3 Oy oxide superconductor and method of

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.

(Hg,Cu)Ba.sub.2 Ca.sub.2 Cu.sub.3 O.sub.y oxide superconductor and

A superconductive oxide material having an infinite layer structure and having the following formula:

Superconductive copper-containing oxide materials of the formula A.sub.p

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.

(Hg,Pb)-Ba-Ca-Cu-O superconductor and method of manufacturing the same

An oxide superconductive material comprising constituent elements mainly composed of ABiCuO in which A comprises at least one element of alkaline earth metals, and having a C-plane orientation, and a method of orienting such superconductive materials by hot extrusion from a rectangular nozzle.

Bi, alkaline earth, Cu extruded oxide superconductive material having a

A method for manufacturing a porous body comprising zirconium oxide and a metal carbide is described. The method comprises mixing a metallic zirconium powder, a metal oxide, and a carbon powder, shaping the mixture in a desired form, and igniting a part or portion of the shaped mixture in an atmosphere inert to a combustion reaction of the shaped mixture. The combustion reaction is caused to continue by the heat of the reaction, so that the zirconium is converted to zirconium oxide, and the metal oxide is reduced with zirconium and converted to a metal carbide to obtain a porous body. This body may be readily divided into fine pieces. If the above procedure is effected under a molding compression pressure, a composite sintered product comprising zirconium oxide and the metal carbide is obtained.

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Urayasu, Japan

Seiji Adachi