The near-surface defect structure of yttria-stabilised zirconia determined by measurement of the differential capacity

Johan E. ten Elshof, M.G.H.M. Hendriks, Henricus J.M. Bouwmeester, H. Verweij

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Abstract

The space charge density at the surface of yttria-stabilised zirconia (YSZ) containing 2–10 mol% yttria was determined from differential capacity measurements of YSZ/gold interfaces at 750–850 K. The oxygen vacancy concentration in the sub-surface layer was determined as a function of temperature and bias potential by fitting the experimental data at positive bias potentials to predictions based on a Boltzmann-type expression. The vacancy concentration at the interface increases with decreasing bias potential, and reaches a temperature-dependent maximum value at negative bias potentials. The thermal activation parameter for this process is 0.27–0.46 eV. A thermodynamic model for the near-surface defect structure of YSZ is proposed, in which oxygen vacancies are assumed to be distributed randomly over a fraction of the total number of oxygen sub-lattice sites. The fraction of sites that is available for oxygen vacancy distribution increases with yttria content and temperature.
Original languageUndefined
Pages (from-to)2564-2571
Number of pages8
JournalJournal of materials chemistry
Volume11
Issue number10
DOIs
Publication statusPublished - 2001

Keywords

  • IR-72260
  • METIS-203050

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