Analysis of Mechanical Loss Spectra in Zirconia Ceramics by Appying the Coupling Model

Mechanical loss spectra (two peaks) observed in ZrO, doped with Y,O, (2-10 mol%), are attributed to oxygen vacancy 0-yttrium (Y) associates (V-Y pairs and V-2Y agglomerates). Both peaks were analysed numerically by applying the coupling model. It has been shown that: i) the activation enthalpy H for both peaks increases with Y20, content, ii) the values of coupling parameter n are about 0.6 0.7, iii) the activation enthalpy H, corresponding to the noninteracting system (dilute case) is about 0.4 eV which is considerably smaller than the activation enthalpy for reorientation of isolated dipoles (0.8 0.9 eV)