Akademik Veri Yönetim Sistemi
1. INTERNATIONAL COLOSSEUM SCIENTIFIC RESEARCHES AND INNOVATION CONGRESS” 13-14, OCTOBER 2024, ITALY, Rome, İtalya, 13 - 14 Ekim 2024, ss.142-143, (Özet Bildiri)
Face–centered
cubic Bi2O3 (δ–phase) is known as a high ion conductivity
solid electrolyte system with anion defect oxygen sublattice. This metastable
phase (729 °C–825 °C), if stabilized, can be an ideal solid electrolyte
candidate for low temperature SOFC units. In this study, different
stoichiometric ratios of Dy–Er co–doped Bi2O3 solid
electrolytes were synthesized by solid state reactions and the effects of heat
treatment temperature on the phase structure and ion conductivity of the
fabricated compositions were investigated. The XRD analyses performed at room
temperature showed that the minor peaks indicating the mixed phase on the
diffraction pattern disappeared with the gradual increase in heat treatment
temperature. In addition, composition 4E4DSB maintained the mixed phase structure
despite different heat treatment temperatures, while the other samples were
stabilized with high ion conductivity cubic δ–phase. The temperature dependent
DTA curves revealed an endothermic peak at approximately 600 °C belonging to
composition 8E4DSB only. Considering the temperature at which this peak
occurred, this endothermal peak can be attributed to the order–disorder
transition occurring only in the oxygen sublattice. The temperature dependent
conductivity curves clearly showed that higher calcination temperature (>750
°C) is more effective in achieving higher ionic conductivity. Also, the
temperature dependent Arrhenius curves showed that the conductivity changed
linearly indicating that it was ionic in character. The FE–SEM images of the
fabricated compositions showed that the pore density increased at low
temperature calcinations (<700 °C), while denser materials were synthesized
at higher temperatures. The EDAX pattern of the compositions revealed that all
elements were present in the mixture without any impurity atoms.