High-temperature superconducting thick films with enhanced supercurrent carrying capability

Abstract

We have developed a multilayer architecture to enhance the supercurrent carrying capability of thick (>1 μm) YBa2Cu3O7−x (YBCO) films. An interlayer of CeO2, which functions as a starting template for growth of subsequent high-quality YBCO layers, is used to prohibit the generation of microstructural defects that otherwise develop in the top region of thick YBCO films. Improved surface quality for a 3.3 μm thick YBCO film has been confirmed by the channeling data of Rutherford backscattering spectroscopy and by scanning electron microscopy. Compared to our routinely prepared single-layer YBCO thick film in which the supercurrent drops rapidly with increasing film thickness, this multilayer makes it possible to maintain critical current density over 1 MA/cm2 with less restrictions on the thickness of coated conductors.