Local Environment of Yttrium in Y-Doped Barium Cerate Compounds

The local structure of yttrium in Y-doped BaCeO 3 compounds was studied using X-ray absorption spectroscopy (XAS) at the Y K-edge. Data analysis shows that the local environment of Y 3+ changes, resulting in a distorted octahedron. The structural distortion found does not depend on the dopant amount at the investigated compositions, but on the level of hydration, as clearly demonstrated by the distortion increase in the BaCe 0.9 Y 0.1 O 3- δ sample after the treatment in O 2 /H 2 O. In situ measurements performed in O 2 /H 2 O flux, which show that the distortion is retained at 753 K, are also reported. The observed significative structural changes seem to point out a preferential insertion of the hydroxyls around the dopant in the Y-doped BaCeO 3 compounds.