Comparative study on T11212/Ag dip-coated tapes fabricated using solid-state and coprecipitation derived powders

Ag clad dip-coated supcrconductor tapes were fabricated from TI-1212 superconducting powders of Tl0.8Bi0.2Sr2Ca0.8Y0.2Cu2O7 starting composition derived via two different methods: the conventional solid-state (SS) and coprecipitation (CP) methods. The effects of using superconducting powders derived from SS and CP methods on phase formation, microstructure and critical current density were investigated for tapes annealed at 850°C for 60 minutes in flowing O2 XRD analysis of the tapes oxide cores indicated a higher volume percentage of 1212 phase for the SS tape compared to the CP tape. However, the oxide Jc of the CP tape (4670 A/cm2) was higher than the SS tape (557 A/cm2). The SEM micrograph of the CP tape s oxide core revealed melted-like fused grains, a factor that was associated with high Jc value of the tape, in contrast to the SS tape s core that displayed cracks and porous microstructure.