The O chemical diffusion coefficient was evaluated, by using the conductivity relaxation method, at 773 to 1173K. Samples of La2Cu0.5Ni0.5O4+δ were selected because of the high value of their surface exchange coefficient. In addition, the O diffusion coefficient was deduced from 18O tracer diffusion profiles. Finally, the O partial pressure dependence of this compound was determined by thermogravimetric analysis. On the basis of these 3 independent experiments, the model of ambipolar diffusion which described diffusion in mixed oxides, was experimentally verified. Dense samples were required for the determination of intrinsic diffusion characteristics.

Measurement of Chemical and Tracer Diffusion Coefficients of Oxygen in La2Cu0.5Ni0.5O4+δ. F.Mauvy, J.M.Bassat, E.Boehm, P.Dordor, J.P.Loup: Solid State Ionics, 2003, 158[3-4], 395-407