High temperature superconducting YBa₂Cu₃O _7-x films on metallic substrates grown in situ by off-axis sputtering

High temperature superconducting YBa₂Cu₃O _7-x (YBCO) thin films were deposited on metallic substrate of Hastelloy C-276 using in situ off-axis rf magnetron sputtering from a single stoichiometric YBa₂Cu₃O_7-x target. Highly c-axis oriented films with a zero resistance temperature of 84 K and critical current density of 1.6×10⁴ A/cm² at 77 K were obtained where BaTiO₃ was used as a buffer layer. Scanning electron microscopy (SEM) surface scan showed quite good surface morphology of the films. The clear interfaces among different regions, confirmed by cross-sectional SEM analysis and Auger electron spectroscopy depth profiling, demonstrated BaTiO₃ to be an effective buffer layer between YBCO and Hastelloy at a temperature as high as 640°C.