The copper-substituted lanthanum nickelate (La2Ni0.5Cu0.5O4+delta) was investigated as possible cathode material for intermediate temperature solid oxide fuel cells because of its mixed ionic and electronic conducting properties (MIEC oxide). The La2Ni0.5Cu0.5O4+delta compound was prepared using the "nitrate-citrate" route. Oxygen permeation fluxes through dense membranes have been measured under various oxygen partial pressure gradients in the 850-1200 K temperature range. The oxygen transport properties are compared with the previous measurements using isotopic exchange depth profile experiments and conductivity relaxation method: all of them show a very good agreement. (c) 2007 Elsevier B.V. All rights reserved.