Cross-Sectional TEM Observation of Ba2YCu3O7-x Film on SrTiO3

Abstract
Ba2YCu3O7-x (BYCO) films epitaxially grown on (100) SrTiO3 substrates were examined by cross-sectional TEM. Near the film/substrate interfaces, the films consist of crystal grains whose boundaries have a regular atomic arrangement over the entire boundary area (coherent boundaries). The c axis of each crystal grain is oriented parallel to one of the three axes of the SrTiO3 substrate. Lattice constants measured with electron diffraction are a=b=c/3=0.390 nm. There are no mixed or amorphous layers at the interfaces.