Doped Cerium Oxide: Effect of Sintering Temperature on Density, Structural and Morphological Properties of Mg, Sr Doped Ceria

Doped Cerium oxide continued to be the candidate electrolyte material due to its stability and superior ionic conductivity compared to YSZ. Strontium doped and Magnesium doped Ceria solid solutions, Ce0.99Sr0.01O1.995 and Ce0.99Mg0.01O1.995 were synthesized by cost-effective solid-state reaction method and were sintered at 1200oC, 1300oC and 1400oC to investigate the effect of sintering temperature and doping on density, structural and morphological properties. The bulk densities were measured by the Archimedes method. X-ray diffraction (XRD) measurements indicate that the synthesized samples were in single-phase cubic fluorite structure (space group Fm3m). The surface morphology was determined using scanning electron microscopy (SEM), micrographs show spherical faceted grains, and the samples were crack-free, dense material with some pores on the surface which are inconsistent with density results. The chemical composition was analyzed by the EDS technique. It is observed that the density increases with increasing sintering temperature and with doping of strontium. The grain size depends on the sintering temperature and type of doping. The lattice parameter increases with sintering temperature and substitution of Sr in ceria. The Grain size of Sr-doped ceria decreases, whereas that of Mg-doped ceria increases. EDS spectra show that the samples are free of contaminants. The Ce0.99Sr0.01O1.995 shows a more open structure than the undoped ceria.