Solid-state synthesis and characterization of Ca-substituted YAlO3 as electrolyte for solid oxide fuel cells

ABO₃-type oxides are recently being explored as solid electrolytes for solid oxide fuel cells. The objective of this work was to study an ABO₃-type perovskite oxide, YAlO_3, for its electrical properties and its suitability as a solid electrolyte. The undoped and doped compositions of Y_{1 - x}Ca_xAlO_{3 - d}( x = 0 - 0.25 ) {{\hbox{Y}}_{1 - x}}{\hbox{C}}{{\hbox{a}}_x}{\hbox{Al}}{{\hbox{O}}_{3 - \delta }}\left( {x = 0 - 0.25} \right) have been synthesized. The phase purity of the samples has been investigated by X-ray diffraction studies. The electrical conductivity studies have been performed using ac impedance spectroscopy in the range 200–800 °C in air. The doped YAlO₃ compositions exhibit a total conductivity of about 1 mS/cm at 800 °C. The microstructural evaluation of the samples has been conducted by scanning electron microscopy and energy dispersive spectrum analysis.