Effect of relaxation on the oxygenK-edge electron energy-loss near-edge structure in yttria-stabilized zirconia

S. Ostanin, A. J. Craven, D. W. McComb, D. Vlachos, A. Alavi, M. W. Finnis, A. T. Paxton
2000 Physical Review B (Condensed Matter)  
The electron energy-loss near-edge structure ͑ELNES͒ at the oxygen K-edge has been investigated in a range of yttria-stabilized zirconia ͑YSZ͒ materials. The electronic structure of the three polymorphs of pure ZrO 2 and of the doped YSZ structure close to the 33 mol %Y 2 O 3 composition have been calculated using a full-potential linear muffin-tin orbital method ͑NFP-LMTO͒ as well as a pseudopotential based technique. Calculations of the ELNES dipole transition matrix elements in the framework
more » ... of the NFP-LMTO scheme and inclusion of core hole screening within Slater's transition state theory enable the ELNES to be computed. Good agreement between the experimental and calculated ELNES is obtained for pure monoclinic ZrO 2 . The agreement is less good with the ideal tetragonal and cubic structures. This is because the inclusion of defects is essential in the calculation of the YSZ ELNES. If the model used contains ordered defects such as vacancies and metal Y planes, agreement between the calculated and experimental O K-edges is significantly improved. The calculations show how the five different O environments of Zr 2 Y 2 O 7 are connected with the features observed in the experimental spectra and demonstrate clearly the power of using ELNES to probe the stabilization mechanism in doped metal oxides.
doi:10.1103/physrevb.62.14728 fatcat:ibb6hax5k5b3nnrwiem6uoc6gi