Solid State Ionics, Vol.121, No.1-4, 31-36, 1999
Oxygen surface exchange in mixed ionic electronic conductor membranes
We discuss the different oxygen surface exchange coefficients and the net surface exchange flux i = c(i)k(i0)[exp(n mu(8)/RT) - exp(2n mu/RT)] at gas-MIEC oxide interfaces, where k(i) = k(i0)(p/p(0))(n) is the surface exchange coefficient, derived from isotope exchange experiments, p is the oxygen pressure, mu(s) and mu are the chemical potentials of the gas and of the ion-electron hole pairs at the interface and c(i) is the oxygen ion concentration. The model is applied to oxygen permeation in planar and tubular membranes.