Abstract
High-T c superconducting Y-Ba-Cu-O ceramics have been prepared using the commercial reagent grade Y2O3, BaC2O4·H2O and CuC2O4·1/2H2O as the starting materials under various sintering conditions. The ceramic microstructure (grain size and relative sintered density) has been confirmed to have a significant influence on the electrical conductivity, but less influence on the superconducting transition temperature, T c.