SYNTHESIS OF HIGH-TC 2223 PHASE IN BI-PB-SR-CA-CU-O SYSTEM BY SHORT-TERM FIRING

The high-T(c) 2223 phase in the Bi-Pb-Sr-Ca-Cu-O system has been synthesized by solid-state reaction. The processing parameters which give the largest volume fraction of the 2223 phase were found as follows. A mixture of Bi2O3, PbO, SrCO3, CaCO3 and CuO was pressed into a bar-shape and calcined at 1133 K for 5h, then cooled to 873 K with a cooling rate of 0.5 K/min. After being pulverized and pressed, the specimen was fired again at 1133 K for 5h and cooled to 873 K with a cooling rate of 0.5 K/min. With these simple synthesizing procedures, a superconducting sample which has a high T(c)-2223 phase volume fraction as high as. 91%, was successfully obtained. Our synthesizing method results in a much greater volume fraction of the 2223 phase than do conventional methods. The zero-resistance temperature of our sample was 102 K.