Kabushiki Kaisha Toshiba

Hiromi Niu

Noburu Fukushima

Hisashi Yoshino

Koichiro Inomata

Ken Ando

Yutaka Yamada

Tetsuhiko Mizoguchi

Isao Sakai

Satoru Murase

Shunji Nomura

Shigeo Nakayama

Tomohisa Yamashita

Misao Koizumi

Masashi Sahashi

Akihiko Tsutai

A starting material which is converted to a continuous body of an oxide superconductor by a heat treatment is filled in a tubular Ag sheath member. The diameter of the filled member is reduced by extrusion to form a wire. The wire is subjected to a heat treatment so that the starting material inside the sheath member is converted to a continuous body of an oxide superconductor. A superconducting wire constituted by the sheath member and the oxide superconductor filled inside the sheath member is obtained. A superconducting coil can be obtained by winding the superconducting wire.

Superconducting wire and method of manufacturing the same

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.

Bi oxide superconductors

An insulating composition consisting of Bi, Sr, RE, Cu, O or of Tl, Ba, RE, Cu, O (wherein; RE is an element selected from a group consisting of Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y) aligns properly with a crystal face of an oxide superconductor because its crystal structure is the same as or similar to that of the oxide superconductor. An insulating composition in which a part of Bi is replaced by Pb is further near the oxide superconductor its construction, and the modulation structure in this insulating composition is mitigated or disappears.

Insulating composition

The polycrystalline magnetic substance for magnetic refrigeration in or gas refrigeration accordance with the present invention comprises a plurality of magnetic alloy fine crystalline powders that include at least one kind of rare-earth element selected from the group of Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb, with the remainder metal consisting substantially of 2 kinds selected from Al, Ni, Co, and Fe, and a metallic binder which forms a compact together with the fine crystalline particles, where the abundance ratio of the metallic binder in the compact is 1 to 80% by volume.

Polycrystalline magnetic substances for magnetic refrigeration and a

A permanent magnet essentially consists of 10 to 40% by weight of R, 0.1 to 8% by weight of boron, 13% by weight or less of gallium and iron, where R is at least one component selected from the group consisting of yttrium and the rare-earth elements. The magnet having this composition has a high coercive force iHC and a high residual magnetic flux density and therefore has a high maximum energy product.

Permanent magnet

A permanent magnet according to the present invention is characterized in that it is composed of an alloy comprising mainly of iron, and R (rare earth element including yttrium), cobalt, and boron, wherein the alloy is formed principally of ferromagnetic Fe-rich phase of tetragonal system and includes a nonmagnetic Laves phase. Compared with the prior rare earth-Fe based magnet, it has higher Curie temperature and has excellent magnetic characteristics, especially the temperature characteristics.

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Tokyo, Japan

Hiromi Niu