Structure and phase composition of nanocrystalline Ce1-xLuxO2-y

The microstructure and phase stability of nanocrystalline mixed oxide LuxCe1-xO2-y (x = 0-1) are described. Nano-sized (3-4 nm) oxide particles were prepared by the reverse microemulsion method. Morphological and structural changes upon heat treatment in an oxidizing atmosphere were studied by transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman and Yb3+ emission spectroscopy, the latter ion being present as an impurity in the Lu2O3 starting material. Up to 950 degrees C, the samples were single phase, with structure changing smoothly with Lu content from fluorite type (F) to bixbyite type (Q. For the samples heated at 1100 C phase separation into coexisting F- and C-type structures was observed for 0.35<0.7. It was also found that addition of Lu strongly hinders the crystallite growth of ceria during heat treatment at 800 and 950 degrees C. (C) 2008 Elsevier Inc. All rights reserved.