Preparation of buffer layer architectures for YBa2Cu3O7−x coated conductors based on surface oxidized Ni tapes

Cube textured NiO layers were prepared by surface oxidation epitaxy on microalloyed Ni tapes. Different perovskite buffers were successfully grown on these substrates using pulsed laser deposition. Among them, BaZrO3 and SrZrO3 buffers show an excellent epitaxial growth on NiO with an in-plane orientation similar to the underlying NiO. The subsequent deposition of YBa2Cu3O7−x on top of these buffers requires a thin intermediate SrTiO3 layer and results in epitaxial layers with a Tc of about 89 K and Jc values up to 1.6 MA cm−2. Alternatively, epitaxial SrRuO3 was grown on NiO using a thin intermediate BaZrO3 layer leading to YBCO films of similar quality. The investigation of the magnetic field dependence of the critical current density shows the major influence of the grain boundary network in the low-field region.