The steady-state oxygen permeation fluxes through dense La2NiO4+delta and La2Ni0.9Fe0.1O4+delta ceramics, studied at 973-1223 K for membrane thickness range 0.6 to 2.0 mm, are limited by both bulk ambipolar conductivity and surface exchange kinetics. The permeability data, in combination with total conductivity and equilibrium P(O-2)-T-delta diagrams, were used in numerical regression analysis to extract the local chemical potential gradients, defect concentrations, partial conductivities and exchange rates. Doping with iron was found to increase oxygen-ion mobility in K2NiF4-type lanthanum nickelate at 1173-1223 K, whilst activation energies remain essentially similar, 69-80 kJ/mol. At lower temperatures, the surface kinetics and ionic transport in La2Ni0.9Fe0.1O4+delta become both slower than those in La2NiO4+delta. Possible defect-interaction and exchange mechanisms relevant to this behavior are briefly discussed. (c) 2007 Elsevier B.V. All rights reserved.