X-ray absorption spectroscopy of doped ZrO2 systems

ZrO2 samples with 11% Nd and La doping and with 7, 9, 11, and 13% Gd doping have been prepared by co-precipitation route followed by sintering at 700 degrees C and 1100 degrees C, for potential application as high conductivity electrolytes in solid oxide fuel cells. The samples have been characterized by x-ray diffraction with laboratory x-ray source of Cu K-alpha radiation and extended x-ray absorption fine structure (EXAFS) spectroscopy measurement at Zr K edge with synchrotron radiation. The XRD spectra have been analyzed to determine the structure of the samples and the EXAFS data have been analyzed to find out relevant local structure parameters of the Zr-O and Zr-Zr shells, viz., bond distances, co-ordinations, and disorder parameters. The effect of change in ionic radius as well as concentration of the dopants on the above parameters has been thoroughly studied. The experimental results, in some cases, have also been corroborated by first principle calculations of the energetics of the systems. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3693470]