Cation transport behavior through the lanthanum strontium cobaltites, La1-xSrxCoO3 (LSC)/lanthanum strontium ferrite, La0.8Sr0.2FeO3 (LSF) interface was examined by X-ray diffractometry (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). Diffusion couples made of La0.8Sr0.2FeO3 (LSF82) and LSCs with different Sr contents (x=0.1 : LSC91, x=0.2 : LSC82 and x=0.5 : LSC55), were treated at 1373 K in air. It has been observed that faceted particles of spinel type CoFe2O4 were precipitated at a detached interface of the LSF82 pellets in the LSC91/LSF82 and LSC82/LSF82 diffusion couples. For the L.SC55/LSF82 couple, cobalt oxide particles were precipitated on the LSF82 surface, while the formation of a Sr rich phase was observed on the LSC55 surface. It has been found that the interface stability of the LSC/LSF diffusion couples strongly depends on the La/Sr composition at the A site of the La1-xSrxCoO3 perovskite compounds. (c) 2007 Elsevier B.V. All rights reserved.