Structural Study of a YBa₂Cu₃O_7-x Superconductor by Anomalous X-ray Scattering

The anomalous X-ray scattering (AXS) measurement at the Cu-K absorption edge has been made using synchrotron radiation for characterizing the atomic scale structure of a YBa₂Cu₃O_7-x superconductor. The measured energy dependence arising from the anomalous dispersion effect of copper was quite consistent with the changes expected from the crystallographic structure factor based on a model of the orthorhombic crystal structure in which an oxygen atom at 1b and 1e sites is partially deficient. This result has also been confirmed by the local environmental structure around copper calculated from the present AXS measurement.