Effect of heavy atom disorder on the intensities of powder XRD lines of YBa2Cu3O7-y

Abstract

It is shown that heavy atom disorder resulting from Y ? Ba, Ba ? Cu and Y ? Cu interchanges due to local stoichiometric constraints can cause significant changes in the intensities of X-ray powder diffraction lines of YBa₂Cu₃O_7-y . A comparison of the theoretically predicted intensities with published patterns for specimens prepared by the conventional dry route reveals that Ba ? Cu interchanges involving copper atoms in the CuO₂ planes can occur quite frequently and may be mistaken for (00l) texture.