Influence of Cation Dopants in the A-Site on the Crystal Structure, Microstructure, and Electrical Conductivity of Ba0.5Sr0.5Co0.8Fe0.2O3-δ as a New Solid-Oxide-Fuel-Cell Cathode

(Ba0:5Sr0:5)1� xCaxCo0:8Fe0:2O3� � (BSCCF), (Ba0:5Sr0:5)0:8La0:2Co0:8Fe0:2O3� � (BSLCF), and (Ba0:5Sr0:5)0:8La0:2� xCaxCo0:8Fe0:2O3� � (BSLCCF) perovskite oxides were synthesized by the modified citrate method and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). These oxides showed primarily a cubic phase with their dense bodies after sintering. The lattice parameter was decreased with increasing Ca 2þ -ion content in BSCCF. Conversely, the substitution of Ca 2þ ions for La 3þ ions in BSLCCF increased the lattice parameter.