Room-temperature deposition of yttria-stabilized zirconia buffer layer on metallic substrates by laser ablation

摘要

THE preparation of high-temperature superconducting (HTSC) wires or tapes is very important for the power application of HTSC. High-J_c properties of Y-Ba-Cu-O thin film at liq-uid-nitrogen temperature are very attractive not only for small-sized electronic devices, but also for large-scale applications such as high-power transmission cables, high-field magnets and large-scale microwave components. Large-current power application would be achieved if high-J_c YBCO films were grown on practical cheapand flexible metallic substrates. An yttria-stabi-lized zirconia (YSZ) buffer layer between the YBCO and metallic substrates was used to prevent the diffusion of the elements from metal to YBCO films. But without epitaxial relationships, there are a large number of large-angle grain boundaries in YBCO film, which limited the J_c ranging from 10~3 to 10~4 A/cm~2. Recently, new methods to solve this problem were reported , i.e. ion beam-assisted deposition (IBAD), was used to align in-plane a and b axes of YSZ deposited on polycrystalline substrates. Biaxially aligned YSZ films were obtained with concurrent off-normal ion-beam bombardment. The YSZ layers effectively controlled the in-plane texture of YBCO films on it. The J_c values were markedly improved to over 10~6 A/cm~2 (-77 K, 0 T).