High Resolution Electron Microscopy of Mixed Uranium Oxides

Fluorite-related structures of mixed uranium oxides (Uy,M1-y)O2−x, where M = Ce, Sc, Y, have been studied using High Resolution Electron Microscopy (HREM). Ordered domains have, been observed directly in crystallites of urania-ceria solid solution. Preliminary investigations of urania-yttria also show evidence for the presence of ordered domains. A possible model for the structure of these regions is suggested.