Defect Interactions and Ionic Transport in Scandia Stabilized Zirconia
Atomistic simulation has been used to study ionic transport in scandia-stabilized zirconia, as well as scandia and yttria-co-doped zirconia, as a function of temperature and composition. The oxygen diffusion coefficient shows a peak at a composition of 6 mole % Sc2O3. Oxygen vacancies prefer to be second nearest neighbours to yttrium ions, but have little preference between first and second neighbour positions with respect to scandium ions. The Sc-O bond length is about 2.17 Å compared to 2.28 Å for the Y-O bond. Oxygen migration between cation tetrahedra is impeded less effectively by Sc-Sc edges than by Y-Y edges. A neutral cluster of two scandium ions with an oxygen vacancy in the common first neighbour position has a binding energy of -0.56 eV. The formation of such clusters may contribute to conductivity degradation of stabilized zirconia at elevated temperature.
- Research Organization:
- Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 958445
- Report Number(s):
- PNNL-SA-64603; 30472; KP1704020
- Journal Information:
- Physical Chemistry Chemical Physics. PCCP, 11(26):5506-5511, Journal Name: Physical Chemistry Chemical Physics. PCCP, 11(26):5506-5511 Journal Issue: 26 Vol. 11; ISSN 1463-9076
- Country of Publication:
- United States
- Language:
- English
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