Critical current densities in thin ceramic tapes of superconducting Ba sub 2 YCu sub 3 0 sub 7.

Tape cast slurries of Ba sub 2 YCu sub 3 0 sub 7 powders offer a convenient means of preparing sintered ceramic samples for critical current density (J sub c) measurements where the transport cross section is small and the current electrode areas are large. Samples were sintered from 900-1000C and characterized for bulk density, grain size, phase composition, T sub c and J sub c. Bulk density and grain size both increase with sintering temperature while all samples were single phase perovskite except for those sintered at 900C. The onset temperature for superconductivity is constant at about 93K while the transition sharpens to R=0 at about 92K for the densest samples. J sub c rises with sintering temperature to a maximum of ~10 sup 3 A/cm sup 2. A linear relationship between J sub c and bulk density is predicted from microstructural considerations.