Joining of different Y-Ba-Cu-O blocks

Two Y-Ba-Cu-O bulk superconductors were joined by using Ag-added Y-Ba-Cu-O as a joining reagent. Two different Y-Ba-Cu-O blocks were prepared individually and subjected to the joining process. Here the joined surfaces were aligned parallel to the (110) plane. A Y-Ba-Cu-O/Ag plate was prepared via a solid state reaction. The plate was sandwiched by two Y-Ba-Cu-O blocks and heated to a temperature between the decomposition temperatures of Y-Ba-Cu-O and Y-Ba-Cu-O/Ag, and further annealed in flowing oxygen. The trapped field distribution of the joint using a Y-Ba-Cu-O/Ag solder with Y211 powders that were not refined by ball milling showed a small dip, corresponding to a decrease of the maximum trapped field values by 15%, while a single peak with no dip was obtained at the joint using a Y-Ba-Cu-O/Ag solder with finely refined Y211.