Ionic conductivity investigation in lanthanum (La) and strontium (Sr) co-doped ceria system

Preparation and characterization of Ce0.85La0.15 − xSrxO{2 − (0.075 + x / 2)} solid electrolytes for intermediate temperature solid oxide fuel cells

“…α R gives the fraction of charge carriers being blocked at the impermeable internal surface under measuring conditions with respect to total number of charge carriers in the samples. The lowest blocking factor, 0.29, has been observed in the sample with x=0.025 at 375°C which is much less than the value 0.90 [25] obtained for singly La-doped ceria. Therefore, it is concluded that strontium is an effective grain boundary scavenger.…”

“…In our previous reports, effect of strontium addition on conductivity of singly La-doped ceria, Ce 0.85 La 0.15 O 1.925 samples having the same number of oxygen vacancies was studied [25]. In the present work, La and Sr co-doped ceria viz Ce 0.85 La 0.15 − x Sr x O {2 − (0.075 + x / 2)} have been prepared to study the effect of increasing oxygen vacancies on the ionic conductivity by changing the concentration of Sr.…”

Densification Behavior and Space Charge Blocking Effect of Bi2O3 and Gd2O3 Co-doped CeO2 as Electrolyte for Solid Oxide Fuel Cells

“…conductivity increases gradually with Bi 2 O 3 doping, which can be attributed to the increase of the free volume demonstrated by Rietveld refinement. The larger free volume can offer a more convenient transportation path for oxygen ions in the bulk, leading to the higher bulk conductivity [42]. However, the grain boundary conductivity changes inconspicuously for all the samples, indicating that there is no relationship between Bi 2 O 3 doping and the grain boundary conductivity.…”

Effect of addition of erbium stabilized bismuth oxide on the conductivity of lanthanum doped ceria solid electrolyte for IT-SOFCs

“…(c) Increasing the lattice strain due to larger size of Bi 3+ (0.117 nm) cation. This increases the number of associated defect pairs and decreases the conductivity [22]. Due to complex interplay of all the above mentioned factors there is an increase in the conductivity up to 0.5 wt.% of ESB and decrease above this concentration.…”