X‐ray multi‐beam resonant diffraction analysis of crystal symmetry for layered perovskite YBaCuFeO5. Issue 5 (23rd September 2016) - Liu, Wen-Chung
Abstract : The possibility of using resonant multi‐beam diffraction to resolve the crystal symmetry of YBaCuFeO5 is demonstrated. Abstract : The open question of crystal symmetry for YBaCuFeO5, still under debate, is resolved by using diffraction anomalous fine structure and resonant multi‐beam X‐ray diffraction at the Fe and Cu K edges. The different asymmetric intensity distributions observed at 7, 7.1305 and 8.9945 keV give direct evidence that the space group of YBaCuFeO5 should be P 4/ mmm with the distance between Cu and apical O atoms longer than that between Fe and O atoms. This approach provides a direct way to resolve detailed structural symmetry which is indeterminate in conventional Bragg diffraction.