Microstructural characterization of YBa/sub 2/Cu/sub 3/O/sub 7-δ/ thin films on SrTiO/sub 3/ using four-axis x-ray diffraction

Microstructural characteristics of YBa/sub 2/Cu/sub 3/O/sub 7-x/ thin films on SrTiO/sub 3/ have an important influence on their physical properties. Four-axis x-ray diffraction methods have been used to characterize textured and non-textured phases in several YBa/sub 2/Cu/sub 3/O/sub 7-δ/ thin films deposited on single crystal SrTiO/sub 3/. The type of epitaxial orientation of a and c axis textured films have been analyzed by tilting the specimen and observing the distribution of YBa/sub 2/Cu/sub 3/O/sub 7-δ/ /102/ plane x-ray intensities over 95% of the reciprocal lattice hemisphere. The ratio of a to e axis material was determined. Several films were found to contain non-epitaxially oriented YBa/sub 2/Cu/sub 3/O/sub 7-δ/, Y/sub 2/BaCuO/sub 5/ and BaCuO/sub 2/. Methods for quantifying the amounts of these random phases are discussed. The existence of stacking faults, such as those caused by the presence of extra Cu-O planes in YBa/sub 2/Cu/sub 3/O/sub 7-δ/, can sometimes manifest itself as a broadening and shifting of diffraction peaks. Consistent with the x-ray data, the stacking faults are readily seen in HREM images