SYNTHESIS AND PROPERTIES OF SUPERCONDUCTING (TL,PB)-(SR,BA)-CA-CU-O THICK-FILMS ON AG

We report successful texturing of screen-printed (Tl,Pb)-(Sr,Ba)-Ca-Cu -O thick (20 mu m) films on both LaAlO3 and Ag foil using rapid therma l processing (RTP) followed by furnace annealing. An RTP cycle to appr oximate to 915 degrees C for 20 seconds in Ar produces massive melting of the superconducting powder but not the Ag substrate. Subsequent an nealing under O, in sealed An foil with a Tl source yields' a brick-wa ll microstrocture consisting of c-axis aligned, plate-like grains. X-r ay diffration and Meissner data show a mixture of the Tl-1223 and Tl-1 212 phases while energy-dispersive spectroscopy identifies the plate-l ike grains its the desired Tl-1223. Magnetization data suggest intergr amular supercurrents flowing across the entire film. Critical current densities inferred from hysteresis are 9x10(4) A/cm(2) at 5 K in low f ields, decreasing by a factor of 5 in 5 tesla.