Structural analysis and electrode performance of Ce doped SrMnO ₃ synthesised by EDTA citrate complexing process

Sr1−xCexMnO3 (SCM, 0·1≤x≤0·4) powders were synthesised by an ethylenediaminetetraacetic acid citrate complexing process, and their properties were investigated. The synthesised Sr1−xCexMnO3 powders showed a pure perovskite phase, whereas the composition with x = 0·4 had second phases. The unit cell volumes increased with increasing Ce content because substituted Ce ions formed some Mn3+ ions, which have a larger ionic radius than Mn4+. The electrical conductivity improved with increasing Ce content up to x = 0·3 (291 S cm−1 at 750°C), revealing a double exchange interaction. Although the electrical conductivity was increased by doping Ce ions, the polarisation resistance increased due to the increase in lattice distortion with doping Ce content. The substitution of Ce ions for Sr in SrMnO3 led to the formation of larger Mn3+ ions than Mn4+ ions and lattice distortion, which would affect the electrical and oxygen ion conductivity.