21. Oxygen Permeation Properties of Perovskite-related Intergrowth Oxides in the Sr-Fe-Co-O System

F. PRADO; T. ARMSTRONG; A. MANTHIRAM

Indianapolis

Encuentro; The American Ceramic Society’s 103nd Annual Meeting and Exposition; 2001

The American Ceramic Society

Sr4(Fe,Co)6013+d and the n = 1, 2, 3 members of the Ruddlesden-Popper (R-P)series (La,Sr)n+i(Fe,Co)nO3n+1 crystallizing in perovskite-related intergrowth structures have been investigated for use as oxygen separation membranes. The oxygen permeation flux JO2 of SrFee-yCoyOn+g for y > 1.5 is due to a Fe-rich perovskite phase present as a secondary phase. The three R-P compounds differ in the oxygen permeation properties. While the Sr3.xLaxFe2-yCoy07-d (n = 2) and LaSr3Fe3-yCoyO10-d (n = 3) phases show oxygen permeation flux values one order of magnitude lower than the SrCo0.8Fe0.203-d perovskite phase, the La1-xSr1+xFe1-yCoy04 (n = 1) phases show negligible oxygen permeability. The Sr3-xLaxFe2-yCoy07 phases show good structural stability at high temperatures.