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A spatial non-uniformity of the switching properties during the fatigue cycling in lead zirconate titanate ceramics was investigated by a quasi-static piezoelectric and a polarization switching measurements. The agreement between the local piezoelectric properties and the switching behavior of segmented samples was demonstrated. The observed spatial variation of the properties and its evolution with cycle number provides clear evidence of the presence of heterogeneous regions that possess a local fatigue state and the local switching behavior. These results can be explained as a result of the build-up of the spatially non-uniform field and the formation of frozen domains in the ceramics during cycling. The statistical analysis of spatial variation of the switching properties and its evolution with cycle number provides the evidence that the heterogeneity of the switching properties during the fatigue cycling in lead zirconate titanate ceramics is mostly related to the non-uniform change of the local characteristic switching time. [ABSTRACT FROM AUTHOR]

Abstract: The dielectric, ferroelectric and fatigue properties of modified lead zirconate titanate (PZT) ceramics were investigated in terms of the effect of La0.8Sr0.2MnO3 (LSM) buffer layers. The double sided LSM buffer layers resulted in a lower dielectric loss, a weaker frequency dependence of dielectric constant, a lower leakage current density, and an increase in the saturation polarization. Moreover, it was found that up to 1.4×107 cycle numbers, the Ag||LSM/PZT/LSM||Ag capacitor, with remanent polarization decreased by 55%, was superior to the Ag||PZT||Ag capacitor by 85%. The results indicate that the LSM buffer layers can improve the fatigue endurance of the PZT ceramics with Ag electrodes, mainly because the accumulated charges were compensated at the interface junctions between the LSM buffer layers and the Ag electrodes. We fit the polarization fatigue data using a modified model and calculated the characteristic decay time of oxygen vacancy migration in the Ag||LSM/PZT/LSM||Ag and the Ag||PZT||Ag capacitors, respectively. [Copyright &y& Elsevier]

Temperature-dependent ferroelectric hysteresis properties of modified lead zirconate titanate ceramics have been investigated in a wide temperature range from 300 to 433 K. It is observed that remnant polarization, saturation polarization, and coercive field are increasing with an increase of the temperature in a low-field region and decreasing in a high-field region. Such behavior is explained by the competition between switching and backswitching mechanisms. A three-stage dependence of the logarithm of the hysteresis loop area on the logarithm of the electric field is identified. The temperature dependence of backswitching properties has been studied. The obtained results indicate that the temperature dependence of the polarization backswitching can be well described by the Arrhenius law. The activation energy for the domain switching determined from the fitting results exhibits decreasing tendency with the increase of the electric field. [ABSTRACT FROM AUTHOR]