The origin of the Pb-rich Bi/sub 3/Sr/sub 2/Ca/sub 2/Cu/sub 1/O/sub x/ (3221) phase during post annealing of (Bi,Pb)/sub 2/Sr/sub 2/Ca/sub 2/Cu/sub 3/O/sub x//Ag composite conductors

We studied the origin of (Bi,Pb)/sub 3/Sr/sub 2/Ca/sub 2/Cu/sub 1/O/sub x/ (3221) in (Bi,Pb)/sub 2/Sr/sub 2/Ca/sub 2/Cu/sub 3/O/sub x/-based (2223) wires by varying the amount of 2223 and remnant liquid in wires using slow-cooling and quenching experiments on 2223 green wires. The 3221 phase forms from crystallization of remnant liquid.