Growth of thick MOD-derived CeO2−x buffer layer with less residual carbon for coated conductors

Abstract

120 nm thick CeO 2-x buffer layer with less residual carbon has been prepared on biaxially textured NiW substrate using a newly developed heat-treatment route by a metal organic deposition approach. The thickness enhancement of CeO 2-x buffer layer was achieved by multiple coatings. The residual carbon removal in CeO 2-x buffer layer was realized by introducing CO 2 into annealing atmosphere at the post-annealed step. Various characteristic methods, including X-ray diffraction, X-ray photoelectron spectra, emission scanning electron microscopy and atomic force microscopy analyses techniques have been applied to investigate the performance of CeO 2-x film. The results show that thick high-quality textured CeO 2-x film with smooth and crack-free surface has been produced at annealing temperature below 1000°C. Furthermore, the atomic concentration of C in such thick CeO 2-x buffer layer prepared using the postannealed step by introducing CO 2 into annealing atmosphere is obviously less than that in CeO 2-x film fabricated in reducing atmosphere of Ar-4 % H 2 . In addition, the introduction of CO 2 into post-annealing step is helpful to the decrease of oxygen vacancy defects in CeO 2-x film, which can suppress the generation of cracks in film. It suggests that CeO 2-x film fabricated by the newly developed heat-treatment route is proved to be a strong candidate as a buffer layer used for the further growth of the oxide film in coated conductors.