A Ce0.8Sm0.15Ca0.05O1.875 (S15C05DC) sample is synthesized by a solid-state reaction serving as a potential electrolyte material for intermediate-temperature solid oxide fuel cells. The sintered sample was found to be dense with a cubic fluorite structure. The addition of Ca2+ can act as a CeO2 sintering aid for accelerating the process. The microstructures and properties of the sample were analyzed by X-ray diffractometry, Raman spectroscopy, scanning electron microscopy, thermomechanical analysis, and transmission electron microscopy. Existing oxygen vacancies in the sample are indicated by a Raman peak at 558 cm(-1). The thermal expansion coefficient of the S15C05DC sample at 200-800 degrees C is approximately 12-14 x 10(-6) degrees C-1. The control of domain size is an important factor for improving the conductivity of S15C05DC. Local clustered nano-domains, with higher Sm2O3 concentrations, were found to regularly arrange to induce the formation of a nanoscale C-type superlattice structure. While Ca doping decreased the formation of the C-type Sm2O3 structure.
