Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1297487 | Solid State Ionics | 2006 | 4 Pages |
Abstract
Single phase perovskite-type oxides La0.2Sr0.8FeO3âÎ (LSF28) and La0.4Sr0.6FeO3âÎ (LSF46) were prepared by the glycine nitrate process. The oxygen nonstoichiometry of LSF46 was studied by precision thermogravimetry at 700 and 900 °C as a function of oxygen partial pressure. Mössbauer spectra were measured at room temperature, as well as at 500 and 700 °C (LSF28) and at 700 and 900 °C (LSF46) under varying oxygen partial pressures. Good agreement is observed for the pO2-dependent nonstoichiometry of LSF46 at 700 and 900 °C as derived from thermogravimetry and in-situ Mössbauer spectroscopy. At low pO2, the Mössbauer isomer shifts and quadrupole splittings indicate a phase transition in LSF46 at 700 °C and in LSF28 at the two temperatures studied from a disordered perovskite phase to a brownmillerite-like structure with larger quadrupole splitting.
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Authors
O. Bartels, K.D. Becker, E. Bucher, W. Sitte,