High-quality epitaxial YBCO thin films directly on LiNbO3

Abstract Pulsed laser deposition was used to deposit high-quality YBa2Cu3O7-δ (YBCO) thin films directly on y-cut LiNbO3 substrates. The as-deposited YBCO films had a high degree of in-plane orientation and showed superconducting transition temperature (T co) at 91 K with a transition width of less than 1 K. Transport critical current densities were found to be ∼ 106 A cm−2 at 77 K and zero field. An ion beam minimum channelling yield of 16% was obtained for YBCO films, indicating high crystallinity. High-resolution transmission electron microscopy studies showed that interface between the film and the substrate was quite smooth and free from interfacial interdiffusion. The defects in thin films are also identified. The work showed that high-quality high T c thin films can be deposited directly on LiNbO3. Novel devices based on the properties of both YBCO and LiNbO3 could be realized based on these results.