Epitaxial growth of YBCO films on metallic substrates buffered with yttria-stabilized zirconia

Abstract

Biaxially textured yttria-stabilized zirconia (YSZ) films were grown on polished Hastelloy C (HC) substrates by ion-beam-assisted deposition (IBAD) and electron-beam evaporation. A water-cooled sample stage was used to dissipate heat generated by the Kaufman ion source and to maintain the substrate temperature below 100°C during deposition. X-ray pole figures were used for texture analysis. In-plane texture measured from the YSZ (111) o>-scan full-width-at-half-maximum (FWHM) was 13.2° and out-of-plane texture from the YSZ (002) ω-scan FWHM was 7.7°. In-plane texture improved with lowered substrate temperature during IBAD deposition. RMS surface roughness of 3.3 nm was measured by atomic force microscopy. A thin CeOz buffer layer (»10 nm) was deposited to improve the lattice match between the YSZ and YBCO films and to enhance the biaxial alignment of YBCO films. YBCO films were epitaxially grown on IBAD-YSZ buffered HC substrates with and without CeO 2 buffer layers by pulsed laser deposition (PLD). In-plane texture FWHMs of 12° and 9° were observed for CeO 2 (111) and YBCO (103), respectively. T c = 90 K, with sharp transition, and Jc values of ≈2 x 10 6 A/cm at 77 K in zero field were observed on 0.5-μm-thick, 5-mm-wide, and 1-cm-long samples.