Abstract:
(Bi2O3)1-x-y(Dy2O3)x(Tm2O3)y ternary systems as electrolytes were synthesized at 750 °C by the solid-state ceramic synthesis
method. Eight (Bi2O3)1-x-y(Dy2O3)x(Tm2O3)y (x = 0.1, 0.2) and (y = 0.05, 0.1, 0.15, 0.2) electrolytes at different ratios were
investigated. The structural, electrical, and thermal properties of these eight electrolytes for solid oxide fuel cells (SOFCs) were
characterized by means of a X-ray powder diffractometer (XRD), the four point-probe technique (4PPT), and thermal gravimetry/
differential thermal analysis (TG/DTA). Results of XRD measurements showed that the δ-Bi2O3 (cubic) phase with a stable
structure was dominantly obtained for all of the samples. As a result of the temperature-dependent electrical measurements of
these ternary systems, it was found that electrical conductivity decreases with increasing molar ratio of Tm2O3. The highest
electrical conductivity was found for the sample of the (Bi2O3)0.85(Dy2O3)0.10(Tm2O3)0.05 system as 0.349 (Ω cm)−1 at 750 °C.
The lowest activation energy was found for the same sample as 0.68 eV.