BPSCCO–Ag powders by a wet method and a low-carbon content for tape preparation
1997
Guidi, G. | SOLCA, M | VILLA, P L | GHERARDI, L
The preparation of BPSCCO-Ag composites by an innovative wet method is described, which allowed admixing of silver in the form of a solution to the solution containing all other cations, and the decomposition of the organic matter in a mild and reproducible way. The citrate route was used without the use of nitrates, ethylene glycol or other reticulating or complexing agents. After drying, silver was found to be dispersed in the powder in metallic form. The powders were treated in an atmosphere containing nitrogen oxides in order to reduce the carbon content. The powders so prepared were suitable for “powder in tube” processing in that they were very reactive toward the 2223 formation and may contain only the desired phases: 2212, metallic silver and Ca₂PbO₄ which, when present in excess, produce a flux that helps texturing and full phase conversion. Preliminary results on the high-purity samples prepared by the powder in tube process show a steady increase of Jc, with the absence of a maximum of Jc with number of treatments, and high texturing of the powder inside the tube.
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