Mitsubishi Metal Corporation

Yukihiro Ohuchi

Takuo Takeshita

Tadashi Sugihara

A target used for forming a thin film of a quinary superconductive oxide contains metal copper ranging between about 8% and about 40% by volume dispersed into a quaternary or a quinary complex oxide, and the metal copper improves the thermal conductivity and the electrical conductivity of the target, so that cracks are less liable to take place in the target and the target is applicable to a d.c. sputtering system, thereby decreasing the production cost of the thin film.

Sputtering target used for forming quinary superconductive oxide

A method for fabricating a low resistivity target for sputtering a bismuth-calcium-strontium-copper oxide superconductor. The method includes the steps of: preparing ingredient powders of a calcium carbonate, a strontium carbonate and a copper oxide; producing a porous bulk body of a complex oxide from the ingredient powders; and impregnating molten bismuth into the porous bulk body of the complex oxide.

Method of making a sputtering target for a bismuth based superconductor

A Ca carbonate powder, a Sr carbonate powder, and a Cu oxide powder are mixed in predetermined proportions, and sintered at a first predetermined temperature into a Ca-Sr-Cu--O oxide sintered body. A Bi oxide powder and a Pb oxide powder are mixed in predetermined proportions, and are sintered at a second predetermined temperature into a Bi--Pb--O oxide sintered body. The obtained Ca--Sr--Cu--O oxide sintered body and Bi--Pb--O oxide sintered body are crushed, and the resulting Ca--Sr--Cu--O oxide powder and Bi--Pb--O oxide powder are mixed in predetermined proportions. The resulting mixed powder is sintered at a third predetermined temperature into a Bi--Pb--Sr--Ca--Cu--O superconductive oxide sintered body, which is crushed into a powder of a Bi-based superconductive oxide containing Pb. A sintered body of the Bi-based superconductive oxide containing Pb is formed from the Bi-based superconductive oxide powder. According to another method, a sintered body of a Bi-based superconductive oxide containing Pb may be manufactured such that a Bi oxide powder and a Pb oxide powder are mixed in predetermined proportions, and sintered at a predetermined temperature into a Bi--Pb-- O oxide sintered body. The Bi--Pb--O oxide sintered body is crushed into a powder, followed by mixing the powder with a Bi--Sr--Ca--Cu--O oxide powder in predetermined proportions into a mixed powder. The above Bi-based superconductive oxide sintered body is formed from the last-mentioned mixed powder.

Method of manufacturing a powder of bi-based superconductive oxide

A target for forming a superconductive oxide film consists of 5 to 40% by volume of metallic copper and 60 to 95% by volume of an oxygen compound of barium and copper, strontium, calcium and copper, or barium, calcium and copper dispersed in the metallic copper, and the target is improved in thermal conductivity, electric resistivity and mechanical strength, because the metallic copper is large in those properties.

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Saitama, Japan

Yukihiro Ohuchi