YBCO FILM GROWTH ON ULTRATHIN AG LAYERS

We discuss our results on the growth of YBCO thin films on ultrathin ( 1-10 nm) Ag underlayers. Substrates were LaAlO3. YBCO was sputter depo sited and Ag thermally evaporated. It was observed that T-c remained r elatively unaffected by the Ag underlayers, ranging from 86-88 K. Crit ical currents were found to be consistent with YBCO grown on bulk Ag w hen the Ag underlayer film reached complete coverage (similar to 9 nm) . Films grown on Ag showed a marked tendency for microcrystalline grow th on the basis of atomic-force microscopy (AFM) results.