Role of grain orientation distribution in the ferroelectric and ferroelastic domain switching of ferroelectric polycrystals
Role of grain orientation distribution in the ferroelectric and ferroelastic domain switching of ferroelectric polycrystals
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DOI：
10.1016/j.actamat.2013.06.044
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发表时间：
2013-09-01
期刊：
影响因子：
9.4
通讯作者：
Zhang, T. -Y.
中科院分区：
文献类型：
--
作者：
Wang, J.;Shu, W.;Zhang, T. -Y.
铁电多晶的非线性机电行为源于极化/畴变，这受到晶界和晶粒取向的影响。采用实空间相场模型，通过计算机模拟研究了晶粒取向分布对二维铁电多晶在电场和/或机械载荷作用下的畴变和非线性行为的影响。相场模拟结果表明，晶粒取向随机分布的多晶体的宏观矫顽场、折射率极化和折射率应变均小于晶粒取向均匀分布的多晶体。然而，随机分布晶粒的多晶材料的应变随电场的变化比均匀分布晶粒的多晶材料的应变随电场的变化大，这表明随机分布晶粒的多晶材料比均匀分布晶粒的多晶材料具有更好的压电性能。铁电多晶的不同宏观非线性行为归因于不同的微观畴变过程。对于晶粒随机分布的多晶，畴变发生在大角度晶界附近区域，而对于晶粒取向均匀的多晶，新的畴则从晶界与材料表面之间的截面形核。(C)2013 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
The non-linear electromechanical behavior of ferroelectric polycrystals stems from polarization/domain switching, which are affected by the grain boundaries and grain orientations. The effects of grain orientation distribution on the domain switching and non-linear behavior of a two-dimensional ferroelectric polycrystal subjected to an electric or/and mechanical load are investigated by computer simulations with a real-space phase-field model. Phase-field simulations indicate that the macroscopic coercive field, remanent polarization and remanent strain in the polycrystal with a random distribution of grain orientation are correspondingly smaller than those in the polycrystal with a uniform distribution of grain orientation. However, the polycrystal with randomly distributed grain has a larger strain variation with the electric field than the polycrystal with uniformly distributed grains, which suggests that the random polycrystal has a better piezoelectric property than the uniform one. The different macroscopic non-linear behaviors of the ferroelectric polycrystals are attributed to different microscopic domain switching processes. For the polycrystal with randomly distributed grains, the domain switching takes place from the regions near the large angle grain boundaries, while new domains nucleate from the cross sections between the grain boundaries and the material surface in the polycrystal with uniform grain orientation. (C) 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.