Journal article
Defect chemistry and oxygen transport of (La0.6Sr0.4-xMx)(0.99)Co0.2Fe0.8O3-delta, M = Ca (x=0.05, 0.1), Ba (x=0.1, 0.2), Sr Part I: Defect chemistry : Part I: Defect chemistry
Risø National Laboratory for Sustainable Energy, Technical University of Denmark1
Electroceramics, Fuel Cells and Solid State Chemistry Division, Risø National Laboratory for Sustainable Energy, Technical University of Denmark2
Fuel Cells and Solid State Chemistry Division, Risø National Laboratory for Sustainable Energy, Technical University of Denmark3
University of Twente4
This paper is the first part of a two part series, where the effects of varying the A-site dopant on the defect chemistry, the diffusion coefficient and the surface catalytic properties of the materials (La0.6Sr0.4 − xMx)0.99Co0.2Fe0.8O3 − δ, M = Sr, Ca (x = 0.05, 0.1), Ba (x = 0.1, 0.2) (LSMFC) have been investigated.
In part I, the findings on the defect chemistry are reported, while the transport properties are reported in part II. Substitution of Sr2+ ions with Ca2+ ions (smaller ionic radius) and Ba2+ ions (larger ionic radius) strains the crystal structure differently for each composition while keeping the average valence of the cations constant.
The Ba2+ containing materials show the largest oxygen loss at elevated temperatures, while the purely Sr2+ doped material showed the smallest oxygen loss. This was reflected in the partial oxidation entropy of the materials. The measured oxygen loss was modelled with point defect chemistry models. Measurements at very low pO2 showed several phase transitions.
Language: | English |
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Year: | 2009 |
Pages: | 1173-1182 |
ISSN: | 18727689 and 01672738 |
Types: | Journal article |
DOI: | 10.1016/j.ssi.2009.05.011 |
ORCIDs: | Hendriksen, Peter Vang |
Coulometric titration LSCF MIEC Mixed conductor Oxide Oxygen stoichiometry