Hitachi, Ltd.

Toshiya Doi

Tomoichi Kamo

Shinpei Matsuda

Kazuhide Tanaka

Toyotaka Yuasa

Seizi Takeuchi

Takesi Ozawa

Yutaka Yoshida

Michiya Okada

Takahiko Kato

Hiroshi Satoh

Kazutoshi Higashiyama

Toshimi Matsumoto

Yoshimi Yanai

Akira Okayama

Atsuko Soeta

Tadaoki Morimoto

Takeshi Ozawa

Takaaki Suzuki

Toshiaki Kusunoki

Kozo Sakamoto

Katsuzo Aihara

Masaru Kadoshima

Kazushige Kohno

Shigeoki Nishimura

Kimihiko Akahori

Nobuhiro Hara

Yoshiteru Chiba

Kazuhisa Mori

Seizi Koike

Shigeru Horii

An object of the invention is to provide: an MgBsuperconducting thin-film wire that exhibits excellent Jcharacteristics even under a 20 K magnetic field; and a method for producing thereof. The MgBsuperconducting thin-film wire includes a long substrate and an MgBthin film formed on the long substrate. The MgBthin film has a microtexture such that MgBcolumnar crystal grains stand densely together on the surface of the long substrate, and has Tof 30 K or higher. In grain boundary regions of the MgBcolumnar crystal grains, a predetermined transition metal element is dispersed and segregated. The predetermined transition metal element is an element having a body-centered cubic lattice structure.

Magnesium diboride superconducting thin-film wire and method for producing same

The present invention provides superconductors capable of being used at temperatures to which the superconductor can be cooled in liquid nitrogen and of carrying current in a high critical current density in a magnetic field, and superconducting apparatuses employing the superconductors and more advantageous in costs than the conventional superconducting apparatuses. A superconducting wire is formed by combining a metallic body of a cubic aggregate structure and an oxide superconducting substance. The present invention provides superconductors, superconducting wires, superconducting magnets and applied superconducting apparatuses having a high superconducting critical current density. The applied super conducting apparatuses employing the superconductors or the superconducting wires in accordance with the present invention are able to operate when cooled in liquid nitrogen-and can be manufactured at costs lower than those of the conventional superconducting apparatuses.

Oxide superconducting wire and method of manufacturing the same

A sodium-sulfur battery in which sulfur and/or sodium polysulfide are used as cathode active materials, and an electronic conductor, which are arranged in a cathode chamber between a cathode container operating concurrently as a cathode electric collector and a solid electrolyte tube, and a layer, made of a material having a superior corrosion resistance against sulfur and sodium polysulfide, is provided between said solid electrolyte tube and said electronic conductor, wherein the cathode electric collector as the electronic conductor has been improved.

Sodium-sulfur secondary battery

This invention provides an oxide-type superconducting flat wire having a critical current density of at least 1,000 A/cm.sup.2, which comprises a Y--Ba--Cu oxide layer having a superconducting property and a silver layer surrounding the oxide layer and has so flat a cross section vertical to the longitudinal direction of the wire that the upper and lower lines between the oxide layer and the silver layers appearing on the cross section having a zone over they are parallel to each other, the thickness of the oxide layer being cold rolled in the range of 0.35 to 0.75 based on the whole thickness of the wire, the whole thickness being 0.2 mm or less, and the metal layer being deformable to follow the shrink deformation of the oxide layer when heat treated to be sintered, but rigid when used. This flat wire is produced by filling a silver-made tube with a Y--Ba--Cu oxide powder having a superconducting property, drawing the tube into a rod wire having a round cross section, then cold rolling the rod wire in the flat wire so that (t.sub.i -t)/t.sub.i .times.100 is equal to or greater than 90%, wherein t.sub.i is the whole thickness of the cross section of the rod wire before the cold rolling and t is the whole thickness of the cold-rolled flat wire, and then heat treating the flat wire to sinter the superconducting oxide.

Superconducting wire and method of producing the same

Superconducting magnet system using a liquid helium for its operation and a permanent current switch and a system thereof applied to the superconducting magnet system employing a permanent current loop created by a superconducting material developing superconductivity when cooled. The system includes a superconducting magnet dipped in the liquid helium, the permanent current switch for driving or interrupting the superconducting magnet, and a cryostat for accommodating the superconducting magnet and the permanent current switch, and the permanent current switch is arranged over a liquid surface of the liquid helium.

Permanent current switch and superconducting magnet system

A superconductive material has the formula

Tl-based superconductive material, a superconductive body, and a method

An oxide-based superconductor ccmprising Tl, Pb, Sr, Ca and Cu or Tl, Pb, Ba, Sr, Ca and Cu, prepared by subjecting a low melting point composition comprising the superconductor-constituting elements and a solid composition comprising the superconductor-constituting elements, prepared in advance, to reaction under melting conditions for the low melting point composition, has distinguished current pass characteristics in a high magnetic field due to improvement of electric contact among grains through reduction of non-superconductor phase, increase in crystal grain sizes (reduction of crystal boundaries), orientation of crystal and cleaning of crystal boundaries.

Oxide-based superconductor, a process for preparing the same and a wire

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.

Laminated super conductor oxide with strontium, calcium, copper and at

Superconductive material, a superconductive body, and a method of

This invention provides an oxide superconductor having a composition of the following general formula of (Tl.sub.a Bi.sub.b Pb.sub.c).sub.x (Sr.sub.d Ba.sub.e).sub.2y (Ca.sub.f Ln.sub.g).sub.y(n-1) Cu.sub.wn O.sub.2n+3+.delta., wherein Ln is at least one selected from Y and rare earth elements, n is 2, 3 or 4, -1&lt;.delta.1, 0.8.ltoreq.x.ltoreq.1.2, 0.8.ltoreq.y.ltoreq.1.2, 0.8.ltoreq.z.ltoreq.1.2 and 0.8.ltoreq.w.ltoreq.1.2, and if a, b and c all are not zero, i.e., greater than zero, a+b+c=1, d+e=1 and f+g=1, and 0&lt;a.ltoreq.1, 0&lt;b.ltoreq.1, 0&lt;c.ltoreq.1, 0.ltoreq.d.ltoreq.1, 0.ltoreq.e.ltoreq.1, 0.3.ltoreq.f.ltoreq.0.99 and 0.01.ltoreq.g.ltoreq.0.7; if b is zero, a+b+c=1, d+e=1 and f+g=1, and 0&lt;a.ltoreq.1, 0&lt;c.ltoreq.1, 0&lt;d&lt;1, 0&lt;e&lt;1, 0.3.ltoreq.f.ltoreq.0.99 and 0.01.ltoreq.g.ltoreq.0.7; if c is zero, a+b+c=1, d+e=1 and f+g=1, and 0&lt;a.ltoreq.1, 0&lt;b.ltoreq.1, 0.ltoreq.d.ltoreq.1, 0.ltoreq.e.ltoreq.1, 0.3.ltoreq.f.ltoreq.0.99 and 0.01.ltoreq.g.ltoreq.0.7; if d and e both are not zero, a+b+c=1, d+e=1 and f+g=1, and 0.ltoreq.a.ltoreq.1, 0.ltoreq.b.ltoreq.1, 0.ltoreq.c.ltoreq.1, 0&lt;d&lt;1, 0&lt;e&lt;1, 0.3.ltoreq.f.ltoreq.1.0 and 0.ltoreq.g.ltoreq.0.7.

Oxide superconductors

The present invention provides a shaped superconductor article such as wire, tape or disk, comprising an oxide superconductor phase and a metal phase in a monolayered or multilayered form, the metal phase comprising a copper, iron, nickel or titanium base alloy containing 1 to 10% by weight of aluminum and having an oxygen-impermeable oxide film formed thereon, preventing the diffusion of oxygen from the oxide superconductor phase to the metal phase.

Ceramic superconductor article

Growing community of inventors

Hitachi, Japan

Toshiya Doi