Effect of dopant on the thermal and electrical behavior of nanostructured ceria materials

Nanopowders with compositions Ce
_0.8
Gd
_0.2
O
_2-δ
(CG), Ce
_0.8
Sm
_0.2
O
_2-δ
(CS), and Ce
_0.9
Eu
_0.1
O
_2-δ
(CE) have been synthesized by a modified Pechini method. X-ray diffraction (XRD) revealed that all powders calcined at 550°C were single phase, with the cubic fluorite-type structure. The good sintering properties of the synthesized nanopowders allowed us to obtain dense ceramics (>97% theoretical density). The ionic conductivities of doped ceria ceramics were investigated as a function of temperature by using AC impedance spectroscopy in the temperature range 300-800°C. The best conductivity was evidenced for the Ce
_0.8
Sm
_0.2
O
_2-δ
sample.