Cation transport behavior, diffusion and interface reaction were investigated for La0.8Sr0.2CoO3 (LSC) and La0.8Sr0.2FeO3 (LSF) perovskite cathodes. Diffusion couples between two perovskite pellets were annealed at around 1071, 1175, 1279 and 1379K. Mass transfer of the iron component from the LSF into the LSC was clearly observed by energy dispersed X-ray analysis and secondary ion mass spectrometry. At the interface, the precipitation of CoFe2O4 spinel phase was observed on the LSF side. On the LSC side interface, Sr-rich thin layer was observed; iron component diffused through the CoFe2O4 and the Sr-rich thin layer at high temperature. The grain boundary diffusion of iron was faster than bulk diffusion. The interdiffusion coefficients in bulk were determined by fitting curves of SIMS profiles.

Cation Transport Behavior in SOFC Cathode Materials of La0.8Sr0.2CoO3 and La0.8Sr0.2FeO3 with Perovskite Structure. H.Kishimoto, N.Sakai, T.Horita, K.Yamaji, M.E.Brito, H.Yokokawa: Solid State Ionics, 2007, 178[21-22], 1317-25

Figure 4

                                          Diffusivity of H in LaScO3