Studies of electron energy loss spectroscopy and selected area electron diffraction ͑SAED͒ were systematically performed on 15 and 25 at. % lanthanide ͑Ln͒-doped ceria samples ͑Ln= Sm, Gd, Dy, and Yb͒, through which the local ordering of oxygen vacancies that develops with increase in doping level was confirmed in the sequence of ͑Gd, Sm͒ Ͼ DyϾ Yb. Furthermore, a monotone correlation between the development of the ordering and the degradation of ionic conductivity with increasing the doping concentration from 15 to 25 at. % was observed. Based on the analysis of SAED patterns, a structural model for the ordering of oxygen vacancies has been constructed, in which the arrangement of oxygen vacancies is similar to that in C-type Ln 2 O 3 oxides and the 1 2 ͗110͘ pairs of the vacancies are preferred. Then, the factors that can influence the formation of the ordering are discussed.

Buckling-driven assembly of 3D mesostructures from releasable multilayers offers versatile design options for unique applications.

25 at. % Rare-earth (RE)-doped ceria samples (RE=Sm, Dy, Y, and Yb) were examined using transmission electron microscopy and electron energy loss spectroscopy, from which the oxygen vacancy ordering in nanosized domains was confirmed. The relationships of the dopant type, oxygen vacancy ordering, and ionic conductivity of doped ceria were established. It is found that the ordering of oxygen vacancies depends strongly on the dopant type, and the development of nanosized domains with a higher degree of ordering can lead to a more dramatic decrease of ionic conductivity in doped ceria.

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