Microstructure and electrical conductivity of LaNi0.6Fe0.4O3 prepared by combustion synthesis routes

The continuing development of new materials suitable for solid oxide fuel cells operating at about 650-800 degreesC is of great interest in recent days. The present investigation deals with the development of a perovskite composition-LaNi0.6Fe0.4O3 (LNF)-prepared following two combustion synthesis routes: citrate-gel (LNC) and urea (LNU). The powders were sintered over a wide temperature range (900-1400 degreesC) and sintering behavior for LNC and LNU was compared. The thermal expansion coefficient (TEC), electrical and microstructural characteristics of LNF was thoroughly investigated. Electrical conductivities were found to be one and a half times higher than that of most commonly used cathode material, La(Sr)MnO3. Moreover, the TEC value of LNF was found to be approximate to11.4 x 10(-6) K-1 at 800 degreesC. The study opens up a possibility of using LNF as a promising cell component for SOFC. (C) 2004 Elsevier Ltd. All rights reserved.