Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7744187 | Solid State Ionics | 2018 | 6 Pages |
Abstract
The ionic conductivity of CaTi0.9Fe0.1O3âδ was determined as functions of oxygen partial pressure and temperature, using two experimental methods: total electrical conductivity measurements by impedance spectroscopy and oxygen isotopic exchange. The data were compared with previously published results. It was demonstrated that, in contradiction with the hypothesis often assumed, the ionic conductivity is not constant in the whole oxygen pressure range. The variation of the ionic conductivity as a function of the oxygen pressure, in the domain where an additional p-type electronic conductivity is observed, was calculated for CaTi0.9Fe0.1O3âδ using our results, and for CaTi0.8Fe0.2O3âδ using data from the literature. At 900â¯Â°C, under air, a decrease of the ionic conductivity of 30% compared to the value under 10â7â¯bar was calculated for the CaTi0.9Fe0.1O3âδ and an increase of 100% was determined for the CaTi0.8Fe0.2O3âδ. This feature was interpreted in terms of the complex defect chemistry of iron-doped calcium titanates.
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Authors
C. Salles, J.M. Bassat, J. Fouletier, D. Marinha, M.-C. Steil,