Conductivity of cerium oxides doped by trivalent cations

For the doping technique with single dopant of Sb2O3,Ga2O3,In2O3,AlCl3,Bi2O3 or Sm2O3,the dopant concentrations of 10%(molar fraction) were selected for the CeO2-based oxygen-ion conductors. A wet chemical method by polymerization of polyvinyl-alcohol was performed for the compound preparation. X-ray diffraction analysis result shows that the calcined powders have nanocrystalline structure with grain size less than 40 nm,and the sintered samples have pure single fluorite-type phase in all doped cerium oxides. Impedance measurement results show that the conductivities and activation energies of CeO2-based oxides depend closely on the dopants. The Sb2O3-doped CeO2 has the largest conductivity and In2O3-doped CeO2 has the lowest one at 200 ℃,the Bi2O3-doped oxide shows the highest activation energy and Al2O3-doped oxide shows the lowest one. Ionic radii and association enthalpies of dopants were taken account for different conductivities and activation energies of the CeO2-based oxygen-ion conductors.

For the doping technique with single dopant of Sb2O3, Ga2O3, In2O3, AlCl3, Bi2O3 or Sm2O3, the dopant concentrations of 10%（molar fraction） were selected for the CeO2-based oxygen-ion conductors. A wet chemical method by polymerization of polyvinyl-alcohol was performed for the compound preparation. X-ray diffraction analysis result shows that the calcined powders have nanocrystalline structure with grain size less than 40 nm, and the sintered samples have pure single fluorite-type phase in all doped cerium oxides. Impedance measurement results show that the conductivities and activation energies of CeO2-based oxides depend closely on the dopants. The Sb2O3-doped CeO2 has the largest conductivity and In2O3-doped CeO2 has the lowest one at 200℃, the Bi2O3-doped oxide shows the highest activation energy and Al203-doped oxide shows the lowest one. Ionic radii and association enthalpies of dopants were taken account for different conductivities and activation energies of the CeO2-based oxygen-ion conductors.