SAMPLE-SUBSTRATE INTERACTIONS DURING MELTING OF BI-2212 ON AG

During melt-processing of Bi2.2Sr2.05Ca0.95Cu2Ox (Bi-2212) thick films and bulk components, a liquid phase is formed which dissolves silver from the silver substrate. The dissolved silver precipitates during co oling as soon as the Bi-2212 phase is reformed. The amount of silver t aken up from the substrate during the whole heat treatment is 3 wt% if the maximum processing temperature T-max does not exceed 910 degrees C and 4 wt% if T-max > 910 degrees C if the starting Bi-2212 powder co ntained no silver. If 2.7 wt% silver were added to the raw Bi-2212 pow der the final silver amount of fully processed samples is 3.5 wt% if T -max < 910 degrees C, but still 4 wt% if T-max > 910 degrees C. Excess ive grain boundary corrosion of the silver substrate can be avoided by adding 2.7 wt% silver to the raw Bi-2212 powder prior to processing.