Synthesis, characterization and spectroscopic analysis of Er-doped ceria (Ce_0.9Er_0.1O_1.95) electrolyte for solid oxide fuel cells

Present investigation deals with the synthesis of nanocrystalline Er-doped CeO2(Ce0.9Er0.1O1.95) ceramic material through a solution combustion process at 500 °C. The as synthesized solid powders were calcined at 700 °C to get crystalline Ce0.9Er0.1O1.95 nanoparticles. Further, cylindrical compacts (7 × 2 mm) were fabricated and sintered at 1200 °C. Crystalline phase and structure of the Er-doped CeO2 was confirmed by powder X-ray diffraction measurements. The crystallite size (∼22 nm) of the calcined particle was calculated from X-ray line broadening method using Scherer's formula for the (111) crystal plane. FTIR and Raman spectroscopic studies were carried out to confirm the chemical composition and functional groups in the material. Raman active mode corresponds to 461 cm–1 was attributed to the symmetric stretching vibration of CeO2 molecule. SEM micrographs and EDX profile of Ce0.9Er0.1O1.95 were recorded to analyse the morphology, agglomeration and presence of elements in the calcined nanoparticles. The grains size range of the sintered body was found to be around 0.2–1 m. The surface morphologies of the sintered and fracture surfaces of the cylindrical pellets were also examined using scanning electron microscope. TEM images revealed the presence of truncated octahedral, spherical-like shape of the nanoparticles with average size about 10–25 nm.