Trends in formation of the nanocrystalline structure and cationic ordering in the Dy2O3-HfO2 (1: 1) system

Evolution of the nanocrystalline structure of the complex oxide Dy₂HfO₅ in the course of thermal annealing at temperatures to 1600°C has been studied by a combination of X-ray and synchrotron methods, including traditional and anomalous X-ray diffraction, PDF, EXAFS, and SAXS. The changes in crystallite size upon annealing of the as-synthesized amorphous precursor have been analyzed in detail. The systematic distortions of a fluorite-type perfect crystal structure (space group $Fmbar 3m$ ) related to the nonequivalence of the local environment of the Dy and Hf cations but not resulting in formation of a pyrochlore-type cationordered structure in this system have been examined.