On the Steady-State Oxygen Permeation Through La[sub 2]NiO[sub 4+δ] Membranes

The steady-state oxygen permeation through polycrystalline , synthesized by a citric acid-based technique and sintered at , has been measured as a function of oxygen gradient, temperature , and membrane thickness . In agreement with earlier reports, the membranes show high permeation rates, comparable to those found for the perovskite-related materials. The self-diffusion coefficient and the surface exchange coefficient of oxygen are extracted from the data through transport modeling using averaged bulk transport parameters and through numerical analysis based on a one-dimensional finite-element method. The self-diffusion coefficient and surface exchange coefficients show Arrhenius-type behavior with activation energies and , respectively, and agree qualitatively with literature data obtained by exchange/secondary ion mass spectroscopy analysis at lower temperatures.