Nanostructured La1-aSraCo1-bFe bO3-x (a=0.3-0.5; b=0-0.2) and Ce0.8Sm 0.2O2 powders were successfully prepared by citrate-nitrate auto-combustion synthesis and were characterized by scanning electron microscopy and X-ray diffraction analysis. Electrochemical Impedance Spectroscopy measurements on symmetric cells were performed to evaluate the applicability of La1-aSraCo1-bFe bO3-x as a cathode material for Single Chamber Solid Oxide Fuel Cells. Our results demonstrated that strontium has a positive effect while iron shows a slightly negative effect on the interfacial resistance. The effect of the electrode sintering temperature was investigated by varying the temperature from 850°C to 1250°C and the best sintering temperature was found to be 900°C. The best characteristics as cathode around the operating temperature of Single Chamber Fuel Cells were found for the composition with a=0.4 and the minimum iron doping; at 700°C, an Area Specific Resistance of 0.13 Ω-cm2 was measured. copyright The Electrochemical Society.