Conductivity relaxation phenomena of the oxide ion conductor Zn2−2xTi1+xO4

Impedance measurements were carried out on the oxide ion conductor Zn2−2xTi1+xO4 in the frequency range between 20 Hz and 106 Hz below 600°C. The frequency dependence of the electric modulus M″ shows the double peak shape in the cubic structure. These results are different from the previously studied Zn2−x/2Ti1−xTaxO4 system where the single and double peaks have been observed for cubic and tetragonal phases, respectively. The M″ profile of the present system was not significantly varied with the composition and activation energies could be obtained from both lower- and higher-frequency peaks. The lower-frequency relaxation was supposed to be related to the long-range ion hopping, since the activation energy obtained from the lower frequency peak is close to that from the conductivity