Composite y₂o₃ ai₂o₃ as diffusion barrier/nucleation layer for hts coated conductors based on ib ad mgo

A composite layer has been successfully implemented in high temperature superconducting (HTS) coated conductors (CCs) based on ion beam assisted deposition (IBAD) MgO technology. This layer serves a dual function: a nucle- ation layer for the growth of high quality biaxially aligned MgO and a diffusion barrier to inhibit interdiffusion between the Ni-alloy substrate and the superconductor. The composition of the composite Y₂O₃ A1₂0₃ influences the texture and superconducting properties of YBCO films grown on STO buffered MgO/Y₂O ₃-Al₂O₃/Ni. Our experimental results demonstrate that the superconducting properties of YBCO grown on STO buffered MgO/Y₂O₃-Al₂O₃/Ni - alloy are comparable with those of YBCO on standard architecture. The use of a single composite Y₂O₃ Al₂O₃ layer instead of individual layers of and Al₂O₃ for the fabrication of HTS CCs based on IBAD MgO provides advantages such as simplified architecture and potentially reduced cost due to the reduced number of fabrication steps.