Interaction between metallic interconnect and constituent oxides of (La, Sr)MnO3 coating of solid oxide fuel cells

The chemical interaction between Fe–Cr alloy interconnect and constituent oxides of Sr-doped LaMnO3 (LSM) coating, La2O3, SrO and Mn2O3, is investigated at 800–900 °C in air. The Cr deposition reaction between the Fe–Cr alloy metallic interconnect and oxides varies significantly with the nature of the oxides. The interaction between the Fe–Cr alloy and La2O3 and Mn2O3 oxide coatings primarily results in the formation of LaCrO3 and (Cr, Mn)3O4 while in the case of SrO oxide coating, Cr2O3 is the main product. In the case of LSM coating, the formation of (Cr, Mn)3O4 and Cr2O3 is identified. The results indicate that the chemical interaction between the Fe–Cr alloy interconnect and LSM coating is most likely related to the surface oxide species such as SrO and MnOx initially enriched or segregated on the surface of LSM particularly in the early stages of the reaction.