Distribution change of oxygen vacancies in layered perovskite type(Sr, La){sub n+1}Fe{sub n}O{sub 3n+1} (n=3)
To elucidate characteristic oxygen vacancy formation in layered perovskite (Sr, La){sub n+1}Fe{sub n}O{sub 3n+1} with the perovskite layer number: n=3, oxygen vacancy content δ of the (Sr{sub 0.775}La{sub 0.225}){sub 4}Fe{sub 3}O{sub 10−δ} (SLF4310) was investigated using a titration technique and a thermogravimetric analysis. The equilibrium constant K for the reduction reaction: Oo{sup ×}+2Fe{sub Fe}{sup ∙} (Fe{sup 4+})=1/2O{sub 2}+Vo{sup ∙∙}+2Fe{sub Fe}{sup ×}(Fe{sup 3+}) was estimated using the vacancy content δ. The Arrhenius plot of the K reveals slope change at approximately 775 °C. From the Rietveld analysis, the oxygen vacancies are the most remarkable at the O2 (O4) sites at lower (higher) temperatures than about 800 °C, which temperature is approximately comparable with that of slope change in the K. These facts mean that distribution of vacancy sites in the SLF4310 changes at approximately 775 °C, accompanying no structural phase transition. The vacancy distribution change affects to the ion conductivity of the SLF4310. - Graphical abstract: Crystal structure of (Sr{sub 0.775}La{sub 0.225}){sub 4}Fe{sub 3}O{sub 10−δ} (SLF4310) at 1000 °C. Display Omitted - Highlights: • Distribution change of oxygen vacancies is appeared at approximately 775 °C. • The distribution change with no structure phase transition is the first observation. • The vacancy distribution change affects the ion conductivity of the SLF4310.
- OSTI ID:
- 22274163
- Journal Information:
- Journal of Solid State Chemistry, Vol. 207; Other Information: Copyright (c) 2013 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
- Country of Publication:
- United States
- Language:
- English
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