Synthesis and characterization of Sm1-xZrxFe1-yMgyO3 (x, y = 0.5, 0.7, 0.9) as possible electrolytes for SOFCs

Paper in proceeding, 2018

The novel perovskite oxide series of Sm 1-x Zr x Fe 1-y Mg y O 3 (x,y = 0.5, 0.7, 0.9) were synthesized by solid state reaction method. X-ray diffraction (XRD), Rietveld refinement, scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and conductivity analysis were carried out. XRD patterns of sintered materials revealed the shifted Bragg reflection to higher angle for the higher content of Zr and Mg. This is related to the ionic size of the dopant elements. Rietveld refinement showed that all compounds crystallized in cubic space group of Fm-3m. SEM images showed that the grains were well defined with highly dense surfaces makes it potential as an electrolyte material in solid oxide fuel cells (SOFCs) or gases sensors. Impedance spectroscopy at 550-800 °C shows that conductivity is higher at higher temperature. Sm 0.5 Zr 0.5 Fe 0.5 Mg 0.5 O 3 shows the highest conductivity of 5.451 × 10 -3 S cm -1 at 800 °C. It was observed that 50% molar ratio of Mg and Zr doping performed highest conductivity.