Anomalous-Diffraction Method Applied to Studying the Structure of the Composite Oxide (Eu2Hf2O7)

The anomalous-diffraction method applied near the absorption edge of Hf is used to investigate the features of atomic ordering in the Eu2Hf2O7 structure. Structural parameterization describing a continuous transition between ideally disordered (fluorite) and ideally ordered (chalcolamprite) structures is proposed. A comparison between the calculated and experimental results demonstrates qualitative coincidence and confirms the hypothesis that the sample under study exists in the intermediate phase. The method is sensitive to cation ordering, but anion ordering of the suggested model is not described.