Oxygen sorption-desorption properties and order–disorder transitions on La–Sr–Co–Fe perovskite-type oxides
The oxygen non-stoichiometry (δ) and structural properties of a brownmillerite-type oxide of La0.1Sr0.9Co0.9Fe0.1O3–δ (LSCF1991) during oxygen sorption/desorption were investigated by simultaneously applying a temperature-programmed technique and high-temperature X-ray diffraction. The structural ch...
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Veröffentlicht in: | Journal of the Ceramic Society of Japan 2019/06/01, Vol.127(6), pp.378-382 |
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Hauptverfasser: | , , , , , , |
Format: | Artikel |
Sprache: | eng ; jpn |
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Zusammenfassung: | The oxygen non-stoichiometry (δ) and structural properties of a brownmillerite-type oxide of La0.1Sr0.9Co0.9Fe0.1O3–δ (LSCF1991) during oxygen sorption/desorption were investigated by simultaneously applying a temperature-programmed technique and high-temperature X-ray diffraction. The structural changes of perovskite-type (P-type) to brownmillerite-type (B-type) and B-type to P-type occurred within limited p(O2) ranges, and a B-type phase-stable region was observed in the presence of oxygen at high temperature. Moreover, P-type LSCF1991 changed into B-type LSCF1991 through tetragonal P-type LSCF1991 as an intermediate phase. B-type LSCF1991 showed repeating structural changes with a certain limited p(O2), which is 0.5% < p(O2) < 1.0%, whereas such changes could not be observed at p(O2) > 1.0%. These behaviors correspond with the temperature programmed desorption of oxygen profiles, as well as the amount of lattice oxygen (3–δ). The p(O2) dependence of the structural change will provide a basis for a further investigation into the durability of an oxygen-permeated membrane by predicting the strain across the membrane under practical conditions. |
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ISSN: | 1882-0743 1348-6535 |
DOI: | 10.2109/jcersj2.19033 |