The O permeation current density through La0.75Ca0.25CrO3 was calculated as a function of the O partial pressure gradient by using a random point defect model. The O permeation current density depended upon the O partial pressure, on the low O partial pressure side, according to: J = PO2-½, when the non-stoichiometry of the perovskite on that side was small. The O permeation current density was independent of the O partial pressure on the high O partial pressure side when the non-stoichiometry of the perovskite at that side was small in comparison with the non-stoichiometry on the low O partial pressure side.

B.A.Van Hassel, T.Kawada, N.Sakai, H.Yokokawa, M.Dokiya: Solid State Ionics, 1993, 66[1-2], 41-7