Microwave-sintered Pr3+, Sm3+, and Gd3+ triple-doped ceria electrolyte material for IT-SOFC applications

The Pr3+, Sm3+, and Gd3+ triple-doped ceria Ce0.76Pr0.08Sm0.08Gd0.08O2-δ material as solid electrolyte for IT-SOFC has been successfully synthesized by sol–gel auto-combustion route. The effect of microwave sintering (1300 °C for 15, 30, and 60 min, named as PSG-MS15, PSG-MS30, and PSG-MS60, respectively) on structural, electrical, and thermal properties of prepared electrolyte material has been studied. Powder X-ray diffraction, scanning electron microscope, energy dispersive spectroscopy, and Raman analysis revealed the single phase, microstructure, elemental confirmation, and structural oxygen vacancy formation of all the samples. Impedance spectroscopy analysis revealed the highest total ionic conductivity, i.e., 3.47 × 10−2 S cm−1 at 600 °C with minimum activation energy of 0.69 eV, in PSG-MS30 sample when compared to PSG-MS15 and PSG-MS60. The thermal expansion measurements have been carried out for PSG-MS30 specimen. The highest total ionic conductivity with minimum activation energy and moderate thermal expansion coefficient of PSG-MS30 sample makes the possibility of its use as solid electrolyte in IT-SOFC applications.