Local structure around Yb in SrZr1-xYbxO3

Local structures around Yb ions in the proton conductor Yb-doped SrZrO3 have been investigated at room temperature by the EXAFS (extended x-ray absorption fine structure) technique. The radial structure functions from the Zr K edge in SrZrO3, SrZr0.95Yb0.05O3 and SrZr0.9Yb0.1O3 and the Yb LIII edge in Yb2O3 show clear contributions by next-nearest ions at 3.0-4.0 Angstrom, while these from the YbLIII edge in SrZr0.95 Yb0.05O3 and SrZr0.9Yb0.1O3 are mainly constructed by a first-nearest signal. Moreover, the nearest Yb-O distributions at 1.0-2.0 Angstrom have a side peak with a strong intensity in both SrZr0.95Yb0.05O3 and SrZr0.9Yb0.1O3. It is shown from the analyses of the side peak that the nearest Yb-O bends consist of two distances (1.96 and 2.18 Angstrom). Two structural models around the Yb ion have been suggested and discussed from these results.