The synthesis of Eu–Tb–Ho co–doped Bi2O3–based ceramic powders for use in intermediate temperature–SOFCs

Abstract

In this study, the solid–state reactions in the ambient atmosphere were used to produce Ho–Tb–Eu co–doped Bi2O3 solid ceramic powder solutions. All samples were stabilized with the cubic δ–phase, according to XRD patterns generated at room temperature. The main peak (111) on the diffraction pattern shifted to larger angles as the total dopant concentration increased, and the average crystal size decreased as well. On the temperature–based DTA curves, neither an endothermic nor an exothermic peak could be seen, indicating that no phase transition took place during the uniform heating circle. According to the conductivity measurement results, sample 5Eu5Tb15Ho had the highest conductivity of 0.288 S/cm at 750 °C and the lowest activation energy of 0.19 eV. The FE–SEM images revealed that the grain size of sample 5Eu5Tb15Ho and Ho–rich samples was not uniform across the surface, and the grain boundary line changed rapidly as the dopant concentration increased.