PREPARATION OF Y-BA-CU-O FILMS ON POLYCRYSTALLINE METAL SUBSTRATES WITH BIAXIALLY ALIGNED YTTRIA-STABILIZED ZIRCONIA BUFFER LAYERS DEPOSITED BY ION-BEAM-ASSISTED PULSED-LASER DEPOSITION

Ion beam assisted pulsed laser deposition of biaxially aligned yttria- stabilized zirconia (YSZ) was used to produce buffer layers for YBaCuO films on polycrystalline metallic substrates. The minimum FWHM of (11 1) phi-scans of the YSZ was 19 degrees, the minimum FWHM of the rockin g curve of YSZ was 4.5 degrees. The lattice parameters of YSZ films de posited with ion beam bombardment were found to be larger than that of the YSZ target. Deposition parameters were optimized. The degree of i n-plane texture increased with increasing ion beam current density and reduced beam divergence. AFM results supported a growth-based orienta tion model. Highly c-axis-oriented biaxially aligned YBCO films were e pitaxially grown by pulsed laser deposition on these layers, having cr itical current density J(c), (77 K, 0 T) = 2.1 x 10(5) A/cm(2) and tra nsition temperature T-c= 90.5 K. (C) 1998 Elsevier Science B.V.