The most important part of a solid oxide fuel cell is the ceramic electrolyte. In this study, cerium oxide (CeO2) was used as the ceramic electrolyte, and different dopant types were used to increase total conductivity. In this study, the most commonly used Sm, and the less frequently used Ho elements were doped simultaneously. As a result, the effect of dope and different synthesis methods on electrolyte properties was evaluated. Three rates were studied with the total amount of Sm-Ho being 20%. The effect of the dopant types on conductivity with critical radius effect was investigated. These dope types were placed in a CeO2 crystal lattice by using the sol-gel and hydrothermal methods. After synthesis, the stable phase was obtained at room temperature. X-ray powder diffraction (XRD) was used for phase determination. The thermogravimetry (TG) determined mass change. Scanning electron microscopy (SEM) was used in the analysis of surface morphology. Total conductivity measurements were measured by the four-probe dc method. After synthesis processes, cubic compounds were obtained. The total conductivity values of the cubic phases samples obtained by two different synthesis methods were compared. The highest conductivity was observed in the sol-gel compounds. The highest electrical conductivity Ce0.80Sm0.10Ho0.10O2 system sol- gel; 6.92x10-3(Ωcm)1- at 655 oC. It was found that the compound obtained as a result of the evaluations could be used ceramic electrolyte application.

Ahmet Hamdi BAKIR and Handan ÖZLÜ TORUN