Effect of bipolar electric fatigue on polarization switching in lead-zirconate-titanate ceramics
Effect of bipolar electric fatigue on polarization switching in lead-zirconate-titanate ceramics
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DOI：
10.1063/1.3452326
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发表时间：
2010-07
影响因子：
3.2
通讯作者：
S. Zhukov;S. Fedosov;J. Glaum;T. Granzow;Y. Genenko;H. Seggern
中科院分区：
文献类型：
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作者：
S. Zhukov;S. Fedosov;J. Glaum;T. Granzow;Y. Genenko;H. Seggern
通过对新鲜和电疲劳条件下PZT的极化开关实验结果的比较，得出疲劳会改变样品内部局部场分布的结论，这是由于产生了离散的缺陷，如空洞和裂纹。这类缺陷的形状和介电常数对整体电场分布有很大的影响。在此假设的基础上，提出了疲劳压电陶瓷极化开关的一种新的现象学模型。该模型假设疲劳试样可以由不同的局部区域组成，这些局部区域表现出不同的场强，但其他区域可以认为是未疲劳的。因此，假定疲劳样品的时间响应是由各自体积分数加权的非疲劳样品的场相关时间响应的叠加。即使在疲劳的早期阶段，也有一部分体积由于域钉住而被排除在整个开关过程之外，这可以通过退火来恢复。不同疲劳试样的实验数据与计算数据具有良好的相关性，证明了该模型的适用性。这些区域形成的合理原因是微裂纹等缺陷的产生以及气孔或空隙等缺陷处电性能的变化。
From comparison of experimental results on polarization switching in fresh and electrically fatigued lead-zirconate-titanate (PZT) over a wide range of applied fields and switching times it is concluded that fatigue alters the local field distribution inside the sample due to the generation of discrete defects, such as voids and cracks. Such defects have a strong influence on the overall electric field distribution by their shape and dielectric permittivity. On this hypothesis, a new phenomenological model of polarization switching in fatigued PZT is proposed. The model assumes that the fatigued sample can be composed of different local regions which exhibit different field strengths but otherwise can be considered as unfatigued. Consequently the temporal response of a fatigued sample is assumed to be the superposition of the field-dependent temporal responses of unfatigued samples weighted by their respective volume fraction. A certain part of the volume is excluded from the overall switching process due to the domain pinning even at earlier stages of fatigue, which can be recovered by annealing. Suitability of the proposed model is demonstrated by a good correlation between experimental and calculated data for differently fatigued samples. Plausible cause of the formation of such regions is the generation of defects such as microcracks and the change in electrical properties at imperfections such as pores or voids.