Agency of Industrial Science and Technology

Agency of Industrial Science & Technology, Ministry of International Trade & Industry

Agency of Industrial Science and Technology Ministry of International

Other

Ube Industries, Inc.

Japan Science and Technology Agency

Ministry of International Trade & Industry

Hideo Ihara

Masayuki Hirabayashi

Hiroko Kaneko

Keiji Kaneko

Akira Negishi

Akira Iyo

Shyam Kishore Agarwal

Ryoji Sugise

Hiroshi Daimon

Itsuhiro Fujii

Hidetaka Ihara, Legal Representative

Gen-ei Ihara, Legal Representative

Chiaki Ihara, Legal Representative

Yoshiko Ihara, Legal Representative

Hideyo Ihara, Legal Representative

Sundaresan Athinarayanan

Shoji Ishibashi

Yoshiyasu Sekita

Masatoshi Jo

Norio Terada

An oxide high temperature superconductor and method of making which includes a first buffer layer composed of CeOformed on a sapphire R (1, &#x2212;1, 0, 2) face substrate for reducing lattice mismatch between the sapphire R (1, &#x2212;1, 0, 2) face substrate and the oxide high temperature superconductor thin film, and a second buffer layer composed of such an oxide high temperature superconductor but in which Ba is substituted with Sr formed on the first buffer layer. The first buffer layer reduces the lattice mismatch between the sapphire R (1, &#x2212;1, 0, 2) face substrate and the oxide high temperature superconductor thin, the second buffer layer prevents an interfacial reaction with Ba, thereby permitting the epitaxial growth of an oxide high temperature superconductor thin film that excels in both crystallographic integrity and crystallographic orientation.

Oxide high-temperature superconductor and its production method

Proposed are a selective reduction type high temperature superconductor and methods of making the same, the superconductor having a pair of charge supply layers each formed of a Cu1-xMx surface ( ), a first superconducting layer formed of a 5-coordination CuO2 surface ( ) and a second superconducting layer formed of a 4-coordination CuO2 surface ( ). Reducing M ions (e.g., Tl ions) in the charge supply layers by heat treatment in a reducing atmosphere enables the 5-coordination CuO2 surface ( ) as the first superconducting layer to be over-doped and the 4-coordination CuO2 surface ( ) as the second superconducting layer to be optimum-doped. According to the present invention, a high temperature superconductor is provided that with its critical temperature held high has a reduced superconducting anisotropy &ggr;, and provides a high critical current density Jc and a high c irreversibility field Hirr.

Selective reduction type high temperature superconductor and methods of making the same

A Mg-doped high-temperature superconductor having low superconducting anisotropy includes a two-dimensional layered structure constituted by a charge reservoir layer and a superconducting layer, wherein some or all atoms constituting the charge reservoir layer are Cu and O atoms, metallizing or rendering the charge reservoir layer superconducting, a portion of the Ca of the Cu Ca O constituting the superconducting layer is replaced by Mg, increasing superconductive coupling between CuO layers, a thickness of the superconducting layer is increased, and therefore coherence length in a thickness direction is increased based on the uncertainty principle, lowering superconducting anisotropy.

Mg-doped high-temperature superconductor having low superconducting anisotropy and method for producing the superconductor

A high-temperature superconductor having low superconducting anisotropy includes a two-dimensional layered structure of crystal unit cells each consisting of a pair of superconducting layer and charge reservoir layer. At least a portion of the atoms of the charge reservoir layer are replaced by atoms giving superconductivity, rendering the charge reservoir layer superconducting and lowering the superconducting anisotropy by increasing the coherence length in the thickness direction.

High temperature superconductor having low superconducting anisotropy and method for producing the superconductor

A copper-based high-temperature superconducting material includes a carrier supply layer overdoped with carriers; and a superconducting layer comprised of at least three CuO,layers that are selectively doped with the carriers; whereby a high superconducting transition temperature (Tc) is maintained to be not less than 116 K, critical current density (Jc) is improved to be 5&times;10,A/cm,(77 K, 0 T), and irreversible field (Hirr) is improved to be not less than 7 T.

Copper-based high-temperature superconducting material

A Mg-doped high-temperature superconductor having low superconducting anisotropy includes a two-dimensional layered structure constituted by a charge reservoir layer and a superconducting layer, wherein some or all atoms constituting the charge reservoir layer are Cu and O atoms, metallizing or rendering the charge reservoir layer superconducting, a portion of the Ca of the Cu,Ca,O,constituting the superconducting layer is replaced by Mg, increasing superconductive coupling between CuO,layers, a thickness of the superconducting layer is increased, and therefore coherence length in a thickness direction is increased based on the uncertainty principle, lowering superconducting anisotropy.

MG-doped high-temperature superconductor having the superconducting anisotropy and method for producing the superconductor

A process for preparing a superconductor which is a low anisotropy, high temperature superconductor, includes providing a target in molded form comprised of one of the superconductor or constituent elements of the superconductor, the superconductor having a layered crystal structure, having a superconducting transition temperature, Tc, of 110 K or more, and having a composition expressed by Cu,M,Ae,Ca,Cu,O,where M is at least one member selected from the group consisting of (a) a trivalent ion of Tl, and (b) polyvalent ions of Mo, W, and Re, Ae is at least one of Ba and Sr, x ranges from 1 to 10, and y ranges from 2x&plus;1 to 2x&plus;4, and z ranges from 0<z&lE;0.5; and forming a film of the superconductor from the target on a substrate by one of sputtering or laser abrasion.

Process for the preparation of a high temperature superconductor

A high temperature superconductor which has a layered crystal structure, which has a superconducting transition temperature, Tc, of 110 K or more, and which has a composition expressed by:

High temperature superconductor

A method for producing a compound oxide superconducting thin film, comprising forming an oxide thin film on the surface of a substrate of a first metal element having a redox charge by oxidizing the metal, using the oxide thin film thus formed as an electrode for oxidation reaction of a second metal element contained in an electrolyte solution or molten salt to incorporate the second metal element in the oxide thin film, using the compound oxide thin film thus formed as an electrode to obtain a cyclic voltammogram, and electrochemically processing the compound oxide thin film at an electrolytic potential that is determined based on the cyclic voltammogram.

Method of producing compound oxide superconducting thin film

A method for the production of a standard oxide sample for X-ray fluorescence analysis of an impurity element contained in an inorganic compound. The standard oxide sample is produced by accurately weighing a high-purity compound of the type of the main-component element of the inorganic compound, dissolving the weighed compound in an acid, adding an element of the type of the impurity element to be subjected to determination in a prescribed amount to the acid solution, evaporating the resultant solution to dryness, and heating the dry residue of evaporation.

Method for production of standard oxide sample for X-ray fluorescence

A method for producing an oxide superconductor comprises obtaining a cyclic voltammogram using an oxide material containing an element having a redox charge as an electrode, determining an electrolytic potential for the oxide material on the basis of the voltammogram, and electrolyzing the oxide material at the determined potential.

Method of producing oxide superconductor

Cubic conductive copper oxide ceramics which are represented by the following formula I:

Growing community of inventors

Tsukuba, Japan

Hideo Ihara