Phase relations in the Bi-(Pb)-Sr-Ca-Cu-Sc-O system

The phase relations in the Bi-(Pb)-Sr-Ca-Cu-Sc-O system were studied near Bi(2)Sr(2)CaCu(2)O(8+delta) (Bi-2212) and (Bi,Pb)(2)Sr(2)Ca(2)Cu(3)O(10+delta) (Bi-2223) between 850 and 930 degreesC. The introduction of Sc led to the formation of a new compound Sr(2)ScBiO(6), which coexisted with Bi-2212 and Bi-2223. Using crystallization from a peritectic melt at different cooling rates, we obtained Bi-2212 matrix composites containing finely dispersed Sr(1.9)Ca(0.1)ScBiO(6) inclusions, with T(c) attaining 89 K. The T(c) of the Bi-2223-Sr(1.9)Ca(0.1)ScBiO(6) superconducting ceramic prepared by solid-state sintering of a Bi-(Pb)-Sr-Ca-Cu-Sc-O precursor was 108.5 K.