Interface reaction and cation transport behavior between perovskite oxides of La1−xSrxCoO3 and La0.8Sr0.2FeO3

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 LSC55/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.