Study of Sm0.2Ce0.8O1.9 （SDC） electrolyte prepared by a simple modified solid-state method

Sm0.2Ce0.8O1.9(SDC) electrolyte was prepared by a modified solid state method at relatively low sintering temperatures without any sintering promoters. The phase composition and microstructure of the electrolytes were investigated by X-ray diffraction(XRD) and field emission scanning electron microscopy(FESEM) technologies. A relative density of SDC electrolyte sintered at 1300 oC reached 97.3% and the mean SDC grain size was about 770 nm. Their ionic conductivity and thermal expansion coefficient were also measured by electrochemical workstation and dilatometer. The electrolyte attained a high conductivity of 5×10–2 S/cm at 800 oC with an activation energy of 1.03 eV and a proper thermal expansion coefficient of 12.6×10–6 K–1.