Polarization switching dynamics by inhomogeneous field mechanism in ferroelectric polymers
Polarization switching dynamics by inhomogeneous field mechanism in ferroelectric polymers
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DOI：
10.1088/0022-3727/45/16/165301
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发表时间：
2012-04-25
影响因子：
3.4
通讯作者：
von Seggern, H.
中科院分区：
文献类型：
--
作者：
Schuetrumpf, J.;Zhukov, S.;von Seggern, H.
铁电体极化反转动力学的研究对于实际应用具有重要意义，半个多世纪以来，铁电体极化反转动力学在铁电陶瓷和铁电聚合物领域得到了稳步的发展。用经典的Kolmogorov-Avrami-Ishibashi成核和生长理论等简单模型不能很好地解释P（VDF-TrFE）等铁电共聚物的极化反转时间行为，本文首次将最近提出的PZT陶瓷的非均匀场机制（IFM）模型应用于聚合物铁电体。该模型是基于这样的假设，即开关体积被划分为许多空间区域与独立的动态，仅由局部电场。由于材料的固有不均匀性，局部场值随机分布在区域的集合上。因此，不均匀的开关行为是由每个区域的变化的局部场引起的。该模型可以从实验数据中直接提取局部场的统计分布，在极化时间和电场值（30-150 kVmm（-1））的8个数量级的宽时域范围内满意地描述了原始P（VDF-TrFE）样品。同样，我们可以得出结论，IFM模型是适应铁电陶瓷和半结晶聚合物。
The understanding of polarization switching dynamics of ferroelectrics is of great importance for practical applications and has been steadily advanced for ferroelectric ceramics and polymers for more than half a century. The temporal behaviour of polarization reversal in ferroelectric copolymers such as P(VDF-TrFE) cannot be satisfactorily explained by simple models such as the classical Kolmogorov-Avrami-Ishibashi nucleation and growth theory.In this paper the inhomogeneous field mechanism (IFM) model recently proposed for PZT ceramics has been applied to polymer ferroelectrics for the first time. The model is based on the assumption that the switching volume is divided into many spatial regions with independent dynamics, only determined by the local electric field. The local field values are randomly distributed over the ensemble of regions due to intrinsic inhomogeneities of the material. Therefore an inhomogeneous switching behaviour is induced by the varying local fields of each region. The statistical distribution of local field values can be directly extracted from the experimental data.The model satisfactorily describes virgin P(VDF-TrFE) samples over a broad time-field domain covering eight orders of magnitude of poling time and electric field values from 30-150 kVmm(-1). In the same way we can conclude that the IFM model is adaptive to both ferroelectric ceramics and semi-crystalline polymers.