The O permeation flux, as deduced from the oxide ion current density through La0.75Ca0.25CrO3, was determined in the steady state, at 1273K, by using an electrochemical method under O partial pressures ranging from 105 to 10-11Pa. The O vacancy diffusion coefficient was estimated to be equal to 1.5 x 10-9m2/s under O partial pressures of between 1 and 10-5Pa. When the partial pressure was lower than 10-5Pa, the ionic current density seemed to depend upon a surface reaction being the rate-determining step. A contribution of grain-boundary diffusion to permeation was considered in the case of an oxidizing atmosphere. The O permeation current density through a 1mm-thick plate was estimated to be 0.03A/cm2.

Determination of the Oxygen Permeation Flux through (La,Ca)CrO3 by an Electrochemical Method. N.Sakai, K.Yamaji, T.Horita, H.Yokokawa, T.Kawada, M.Dokiya, K.Hiwatashi, A.Ueno, M.Aizawa: Journal of the Electrochemical Society, 1999, 146[4], 1341-5