Investigation into the effect of Si doping on the cell symmetry and performance of Sr1−yCayFeO3−δ SOFC cathode materials

X-ray diffraction patterns for: (left) Sr0.75Ca0.25Fe1−xSixO3−δ (x=0, 0.05, 0.10 and 0.15) and (right) Sr0.25Ca0.75Fe1−xSixO3−δ (x=0, 0.05, 0.10 and 0.15), showing the stabilization of the cubic form of these series through silicon doping. For the latter Sr0.25Ca0.75Fe1−xSixO3−δ phase, the stabilisation is not quite complete at 15% Si doping.