Solid solubility and transport properties of Ce 1− x Nd x O 2−δ nanocrystalline solid solutions by a sol-gel route

摘要: Ce 1− x Nd O 2−δ ( = 0.05 to 0.55) nanocrystalline solid solutions were prepared by a sol-gel route. X-ray diffraction analysis showed that crystallized in cubic fluorite structure. The lattice parameter for the increased linearly with dopant content. solubility of 3+ ceria was determined be about 0.40 terms nearly constant parameters at level larger than 0.40. First-order Raman spectra lower content exhibited one band associated F 2 g mode. At higher contents, mode became broadened and asymmetric, new broad appeared frequency side This assigned oxygen vacancies. electron paramagnetic resonance spectrum presence − adsorbed on sample surface 2.02 2.00 symmetry 1.97 1.94. Further increasing led disappearance signals . Impedance bulk grain boundary conduction solutions. conductivity maximum an activation energy minimum 0.80 0.20 give promising properties such as relatively high σ 700 °C 2.44 × 10 −2 S cm −1 moderate E 0.802 eV. variations explained relative vacancies V o defect associations {Ce ′V }/{Nd }.