The effect of Ag on the decomposition pathway of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub x} in air

The decomposition pathway of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub x} (Bi2212) in .21 bar O{sub 2} with 0, 2, and 10 wt.% Ag added has been determined by performing SEM/EDS and microprobe analysis on oil quenched samples. A series of quaternary phase diagrams were constructed to describe the evolution of the phase assemblage with temperature. It was found that the first decomposition products are Bi{sub 9}Sr{sub 11}Ca{sub 5}O{sub x} (9{und 11}5), (Sr{sub 1{minus}x}Ca{sub x})CuO{sub 2} (11), and liquid. The addition of Ag acted to depress the first peritectic temperature by 16--20 C and slightly modified the order in which some of the subliquidus solid phases nucleate and decompose. The effect of C on the peritectic melting temperature was examined through thermal analysis of powder samples.