Oxygen relaxation and oxide ion conduction of Zr0.8 − xCexY0.2O1.9 (x = 0, 0.3, 0.5)

Oxide ion conductivity and internal friction were examined for yttria and ceria co-doped cubic zirconia solid solution. The maxima of the internal friction (IF) were observed for Zr0.8 − xCexY0.2O1.9 (x = 0, 0.3, 0.5) polycrystals in the temperature range of 300–680 K at 3.2 Hz using forced torsion method. The CeO2 addition reduced both the oxide ion conductivity in low temperature range and IF peak amplitude of Zr0.8 − xCexY0.2O1.9. The possible structural relaxation is proposed to decrease ionic conductivity by increasing Ce concentration in Zr0.8 − xCexY0.2O1.9 even with the same vacancy concentration.