Domain wall and volume contributions to material properties of PZT ceramics

Abstract A set of complex dielectric, piezoelectric and elastic constants has been measured in a temperature range between 4.2 K and the Curie point on undoped and Fe-doped PZT samples. All samples show a pronounced relaxation below 400 K which is attributed to domain wall vibrations according to an earlier developed model. A separation procedure allows to distinguish between the domain wall and the volume parts of the material constants. The relaxation peak in the losses and therefore the domain wall parts are shifted to higher temperatures by increasing the Zr content and they exhibit maximum values at the MPB. The volume contributions show a maximum at the MPB too. By increasing the Fe content the relaxation peak is shifted to lower temperatures and it decreases. This behaviour and the frequency dependence can be fitted by distributed thermally activated relaxation processes.