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

Elshof ten, Johan E. and Hendriks, Mark G.H.M. and Bouwmeester, Henny J.M. and Verweij, Henk (2001) The near-surface defect structure of yttria-stabilised zirconia determined by measurement of the differential capacity. Journal of Materials Chemistry, 11 (10). pp. 2564-2571. ISSN 0959-9428

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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.
Item Type:	Article
Copyright:	RSC Publishing
Faculty:	Science and Technology (TNW)
Research Group:	Inorganic Materials Science (IMS) Inorganic Membranes (IM)
Link to this item:	http://purl.utwente.nl/publications/72260
Official URL:	http://dx.doi.org/10.1039/b100923k
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