Sb. Qadri et al., MICROSCOPIC X-RAY CHARACTERIZATION OF INHOMOGENEITIES IN YBCO CRYSTALS WITH SHARP SUPERCONDUCTING TRANSITIONS, Physica. C, Superconductivity, 282, 1997, pp. 93-96
High resolution x-ray diffraction measurements of YBCO single crystals
with optimal transport properties reveal gross structural inhomogenei
ties, such as domains of different oxygen content and high dislocation
densities. Thin epitaxial YBCO films show similar structural inhomoge
neities.