Oxide Ion Transport in Donor-Doped Pb(ZrxTi1−x)O3: The Role of Grain Boundaries
Abstract:Oxygen vacancies play a role in various proposed degradation mechanisms of Pb(ZrxTi1−x)O3 (PZT)-based applications. Hence, 18O tracer diffusion experiments investigated by time-of-flight-secondary ion mass spectrometry were used in order to evaluate oxygen diffusion in donor-doped polycrystalline PZT. The PZT shows fast grain-boundary diffusion for annealing temperatures around 650°C with a strong temperature dependency. 18O intensity images clearly coincide with maps of grain boundaries. Within individual grains, local diffusion profiles could be measured and revealed bulk diffusion as well as evidence of a near-surface space–charge layer. The bulk and grain-boundary diffusion coefficients for the samples annealed at 650°C could be calculated with respect to type B diffusion kinetics. Comparison with electrical measurements showed that oxide ion conduction in grain boundaries significantly contributes to the total conductivity of donor-doped PZT.
Document Type: Research Article
Affiliations: Christian-Doppler-Laboratory for Ferroic Materials, Institute for Chemical Technologies and Analytics, Vienna University of Technology, 1040 Vienna, Austria
Publication date: April 1, 2011