Epitaxial growth and characterization of dual-sided Y2O3 buffer layer for superconducting coated conductors

In this work, a dual-sided buffer template, which allows the deposition of YB2Cu3O7-delta (YBCO) coated conductors on both sides, has been proposed and investigated. Theoretically, in contrast to traditional YBCO structure on one side, the performance of critical current in YBCO films has been improved by two times. In this buffer structure, the dual-sided Y2O3 films were grown on a flexible metal template by a home-made reel-to-reel dynamic direct current sputtering system and the film growth parameters were systematically investigated. The microstructure were characterized by in situ reflection high-energy electron diffraction monitoring in real time during the deposition stage. X-ray diffraction, and atomic force microscopy were used to detect the biaxial texture and surface morphology, respectively. What's more, by the application of stopping and range of ions in matter software, it helped us to understand the influence of deposition parameter to the growth rate of Y2O3 films. Finally, the biaxial texture of dual-sided Y2O3 film yielded out-of-plane texture of Delta omega = 4.2 degrees and in-plane texture of Delta Phi = 5.2 degrees for one side, as well as Delta omega = 5 degrees and Delta Phi = 5.3 degrees for the second side. Subsequently, the dual sided YBCO superconducting films were coated on the above Y2O3 buffer layer by low-cost metal-organic chemical vapor deposition method with critical current of 30 A/cm and 60 A/cm for each side.