Structural and Conductivity Studies of YDC-CYC Electrolyte

Abstract

The effect of Ca addition (0-9 wt %) on the structure, densification, conductivity and thermal expansion of Ce_0.8Y_0.2O₂ was studied. The Ce_0.8(Y_1-xCa_x)_0.2O₂ (x = 0, 0.15, 0.3 and 0.45) samples were prepared through the sol-gel process. Structure and phase was confirmed by XRD. Dense Ce_0.8(Y_1-xCa_x)_0.2O₂ ceramics were obtained through sintering the pellets at 1300 ºC. The surface morphology of the sintered pellets was analyzed using SEM. Thermal expansion was studied by dilatometer. The two-probe A.C. impedance spectroscopy was used to study the grain ionic conductivity of doped and co-doped ceria in the temperature range 300-700 ºC. The composition Ce_0.8Y_0.17Ca_0.03O₂ showed improved grain ionic conductivity and minimum activation energy.