Microstructural Characterization of Ba2YCu3O7 Films Produced by Co-Evaporation

Ba2YCu3O7 films produced by co-evaporation of BaF2, Cu and Y onto S1TiO3 substrates in an O2 ambient followed by post-annealing were analyzed using RBS, X-ray diffraction and Auger microscopy. These films exhibit Tc's (R=0) of =90K and a best Jc of > 1.0×106 A/cm2 at 81K for a =2500A thick film. RBS and Auger depth profiling limit the level of F present in the post-annealed films to