TEM AND SEM STUDIES OF EPITAXIAL YBA2CU3O7-X SUPERCONDUCTING THIN-FILMS

The microstructure of high-T(c) epitaxial YBCO superconducting thin films have been investigated using high-resolution transmission electron microscopy and scanning electron microscopy. It is found that the epitaxial growth of the film is closely related to not only deposition conditions, but also the surface quality of the substrate. The experimental results show that in epitaxial YBCO superconducting thin films grown on (100) SrTiO3 single crystal substrates, the interface layer, defects, and undesirable orientations are the main elements which degrade the critical current density J(c) of the film.