Aisin Seiki Kabushiki Kaisha

Yuh Yamada

Uichiro Mizutani

Masami Ishii

Tetsuo Oka

Yoshitaka Ito

Yousuke Yanagi

Masaaki Yoshikawa

Takeo Yamazaki

Yoshitaka Itoh

Takayuki Nishio

Motohiro Suganuma

Fumihiko Ogasawara

Atsushi Takagi

An Nd-Ba-Cu-O bulk superconductor includes oxide including metallic elements of neodymium (Nd), barium (Ba) and copper (Cu), and has a structure in which fine particles of Nd.sub.4 Ba.sub.2 Cu.sub.2 O.sub.10 (i.e., Nd422) are dispersed uniformly in crystalline grains of NdBa.sub.2 Cu.sub.3 O.sub.x (i.e., Nd123). It is produced by preparing a mixture powder in which an Nd123 powder and an Nd422 powder are present uniformly, thermally treating the mixture powder in a temperature range where the Nd123 powder melts partially at least but the Nd422 powder hardly melts, and gradually cooling the partially melted mixture powder in a temperature range around a solidifying point of the Nd123 powder. It exhibits an enhanced magnetic-field-trapping capability in the regions of low magnetic field, because of the pinning effect resulting from the fine particles of Nd422 dispersed uniformly in the crystalline grains of Nd123.

Neodymium-barium-copper-oxide bulk superconductor and process for

A superconductive ceramic composite material with high strength and capable of plastic deformation is prepared by mixing and sintering a superconductive powder represented by (RE.sub.x AE.sub.1-x).sub.1-y Cu.sub.y O.sub.z (RE represents Y or a rare-earth element having an atomic number of 57-71, or a combination of at least two of these elements, AE is at least one of alkaline earth elements Ca, Sr and Ba, x is 0.13-0.67, y is 0.25-0.67, and z is 1.08-1.17) and a metal powder M (M represents at least one of noble metals Rh, Pd, Ag, Ir, Pt and Au), in a defined ratio. The deformation (e.g., rolling) is followed by reheat-treatment (resintering). The powder mixture can be enclosed in a metallic capsule or made into a clad sheet by interposing the powder within two metallic sheets, and deformed (drawn or press formed into a desired shape) followed by sintering. The composite material may contain a superconductive network of such grains.

Superconductive ceramic composite material

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Aichi, Japan

Yuh Yamada