Process for producing Bi-Ca-Sr-Cu-O, TL-Ca-Sr-Cu-O and Tl-Ba-Ca- Cu-O superconducting ceramics

摘要

1. In the (Bi,Tl)-Ca-(Sr,Ba)-Cu-O based superconducting ceramics production process, a process for preparing superconducting ceramics characterized byPP(a) providing powders includingP Pi) a compound of Bi oxide or Tl oxide, PPii) a Ca compound,PPiii) an Sr compound or Ba compound, and PPiv) a Cu compoundPP as starting powders; PP(b) compounding and mixing powders from compounds of the starting powders, the compounds each having lower vapor pressure, i.e., powders from compound ii), compound iii), and compound iv) at a compounding ratio to obtain a mixture, and primarily calcining the mixture at a temperature of 850 to 1050 C., to form a Ca-- (Sr,Ba)--Cu--O based oxide; andPP(c) further mixing the Ca--(Sr,Ba)--Cu--O based oxide with a compound having a higher vapor pressure, that is, the powder of compound i), at a compounding ratio, and secondarily calcining at a temperature of 500 to 820 C.