Epitaxial thick film of YBCO by high temperature spray pyrolysis for coated conductors

Abstract

YBCO thick films have been synthesized using a low cost spray pyrolysis method. We used an all nitrate precursor approach to grow epitaxial HTS oxide film on SrTiO 3 (0 0 1) substrate at a high deposition rate and at high temperature (over 800 °C). In these experiments thick YBCO films (μm) were grown in situ at 850 °C within 4 min; the final sintering process is performed at the same temperature for 2 h under oxygen atmosphere before low temperature oxygen loading. X-ray diffraction results ( θ–2 θ scans and ϕ scans) show that the films have not only a strong c-axis texture (mis-orientation ∼0.4°) but also a sharp in-plane biaxial orientation (mis-orientation is ∼1.4°). The critical temperature ( T c) was 91 K and the critical current density ( J c) higher than 1.4×10 6 A/cm 2 (at 77 K, 0 T), while film thickness is over 1 μm. Spray pyrolysis is a promising technique for coated conductors.