Oxygen Permeation Properties of the Intergrowth Oxide Sr3-xLaxFe2-yCoyO7-

F. PRADO; T. ARMSTRONG; A. MANTHIRAM; A. CANEIRO

Saint Louis

Encuentro; The American Ceramic Society’s 102nd Annual Meeting and Exposition; 2000

The American Ceramic Society

The structural stability and oxygen permeation properties of the perovskiterelated intergrowth oxides Sr3-xLaxFe2-yCoy07-d with x = 0.0 and 0.3 and y = 0.0 and 0.6 have been studied at high temperature (800 < T < 900°C) and in the oxygen partial pressure (PO2) range between air and pure N2. Samples with x = 0 show instability on exposure to ambient air conditions while samples with x = 0.3 are stable. High temperature X-ray diffraction data reveal no phase transitions for these compounds at 900 °C in pure nitrogen. The volume expansions of the Sr3-xLaxFe2-yCoy07-d oxides due to changes in oxygen content at 900 °C are lower than those for the perovskite phase SrCoosFeojOs-g. Oxygen permeation flux values for the Sr3_xLaxFe2-yCoy07-d compounds are approximately one order of magnitude lower than those for the perovskite phase SrCoo.8Feo.203-d. The oxygen permeation flux increases with increasing Co content, but decreases with the substitution of La for Sr.