Structure and Mixed Electronic-ionic Conducting Properties of La_(0.6)Sr_(0.4)Co_(1-y)Fe_yO_3(y=0-1.0) Ceramics Made by a Citrate Method

摘要

La_(0.6)Sr_(0.4)Co_(1-y)Fe_yO_3(y=0-1.0) powders were synthesized by a citrate method,and the structure and mixed electronic-ionic conducting properties of the resulting ceramics were investigated. The synthesized La_(0.6)Sr_(0.4)Co_(1-y)Fe_yO_3 powders have a pure perovskite structure and consist of uniform and fine particles.A perovskite structure with rhombohedral symmetry was certified for the La_(0.6)Sr_(0.4)Co_(1-y)Fe_yO_3 ceramics.The increase of Co/Fe ratio significantly promoted the grain growth and microstructural densification. The La_(0.6)Sr_(0.4)Co_(1-y)Fe_yO_3 compositions with relatively higher Co/Fe ratio exhibit superior mixed conducting properties.The electronic structure and microstructure of the ceramics are responsible for the variation of the mixed conducting properties with Co/Fe ratio.