Microstructural characterization of terbium-doped ceria

The microstructures of Ce1−xTbxO2−δ (0.10 ≤ x ≤ 0.50) sintered samples were studied systematically using transmission electron microscopy. The sintered samples consist of not only fluorite-structured matrix but also nano-sized precipitates. Correspondingly, diffuse scattering and extra reflections related to the precipitates were observed in the selected area diffraction patterns. The composition of the precipitates was studied quantitatively by electron energy-loss spectroscopy, indicating that the precipitates have higher Tb concentration than that of the matrix. Furthermore, Tb3+ and Ce3+ cations were observed to segregate in the precipitates.