Orientation of Ce-Y-Zr-O films deposited by reactive sputtering onto oxidized NiCr-tapes and Ni films

The growth of Ce-Y-Zr-O (CYZ) buffer layers for YBa₂Cu₃O_7-δ deposition on textured Ni-tapes was studied under idealized conditions on [100]-SrTiO₃ (STO) single crystals and epitaxial Ni films and under real conditions on textured NiCr-tapes. The metallic substrates were epitaxially surface oxidized prior to deposition. The subsequent CYZ-layer was produced by rf sputtering employing combined planar and cylindrical targets and was characterized by x-ray diffraction (XRD) and Rutherford Backscattering. Films sputtered on STO-single crystals were 100 nm thick, had lattice constants between 0.5191 and 0.5443 nm, and out-of-plane mosaic spreads between 0.6 and 3.2°. Best films grown on epitaxially surface oxidized Ni films and NiCr-tapes had lattice constants of 0.5220 and 0.5226 nm, and out-of-plane mosaic spreads of 2.3° and 6.8°, respectively and were highly [100]-orientated (> 95%).