Joining of Y–Ba–Cu–O/Ag bulk superconductors using Er–Ba–Cu–O/Ag solder

Abstract

Ag-added Y–Ba–Cu–O bulk superconductors were joined using Ag-added Er–Ba–Cu–O solder and different Er211 contents. Microstructural analysis revealed that the volume fraction of Er211 at the joint with a composition of Er123:Er211 = 4:1 was the same as that for the expected volume fraction of the initial composition. That is, this composition seems to be optimum, since the mass balance was maintained during the crystal growth from the initial growth stage to the final stage. The trapped-field distribution for the joint using this composition was uniform and the only single peak indicated that strong coupling was achieved.