Ceria samples, doped with 25at% of rare earths (Sm, Dy, Y or Yb), were examined by using transmission electron microscopy and electron energy loss spectroscopy (from which O-vacancy ordering in nanosized domains was confirmed). Relationships between dopant type, O vacancy ordering and ionic conductivity were established. It was found that the ordering of O vacancies depended strongly upon the dopant type. The development of nanosized domains having a higher degree of ordering could lead to a more marked decrease in the ionic conductivity of doped ceria.

Oxygen Vacancy Ordering in Heavily Rare-Earth-Doped Ceria. D.R.Ou, T.Mori, F.Ye, T.Kobayashi, J.Zou, G.Auchterlonie, J.Drennan: Applied Physics Letters, 2006, 89[17], 171911 (3pp)