STUDY OF HIGH-QUALITY EPITAXIAL YBCO THIN-FILMS GROWN DIRECTLY ON Y-CUT LINBO3

Pulsed laser deposition was used to deposit high-quality YBa2Cu3O7-del ta (YBCO) thin films directly on y-cut LiNbO3 substrates. The as-depos ited YBCO films had a high degree of in-plane orientation and showed s uperconducting transition temperature (T-co) at 91K with a transition width of less than 1K. Transport critical current densities were found to be similar to 10(6) A/cm(2) at 77K and zero field. An ion beam min imum channeling yield of 16% was obtained for YBCO films, indicating h igh crystallinity. High-resolution transmission electron microscopy st udies showed that the 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 hig h T-c thin films can be deposited directly on LiNbO3. Novel devices ba sed on the properties of both YBCO and LiNbO3 could be realized based on these results.