Revealing the role of defects in ferroelectric switching with atomic resolution
Revealing the role of defects in ferroelectric switching with atomic resolution
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DOI：
10.1038/ncomms1600
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发表时间：
2011-12-01
影响因子：
16.6
通讯作者：
Pan, Xiaoqing
中科院分区：
文献类型：
--
作者：
Gao, Peng;Nelson, Christopher T.;Pan, Xiaoqing
铁电材料的特征在于自发极化，其可以随着施加的电场而重新取向。极化域之间的切换由纳米级缺陷介导。理解铁电开关中缺陷的作用对于非易失性存储器等实际应用至关重要。对于铁电纳米结构和薄膜尤其如此，其中整个切换体积接近缺陷表面。本文报道了用原位透射电子显微镜观察到的四元PbZr（0.2）Ti（0.8）O（3）薄膜在外加电场作用下的纳米铁电开关。我们发现铁电/电极界面处形成的本征电场决定了铁电畴的成核位置和生长速率以及畴壁的取向和迁移率，而位错对畴壁运动施加较弱的钉扎力。
Ferroelectric materials are characterized by a spontaneous polarization, which can be reoriented with an applied electric field. The switching between polarized domains is mediated by nanoscale defects. Understanding the role of defects in ferroelectric switching is critical for practical applications such as non-volatile memories. This is especially the case for ferroelectric nanostructures and thin films in which the entire switching volume is proximate to a defective surface. Here we report the nanoscale ferroelectric switching of a tetragonal PbZr(0.2)Ti(0.8)O(3) thin film under an applied electric field using in situ transmission electron microscopy. We found that the intrinsic electric fields formed at ferroelectric/electrode interfaces determine the nucleation sites and growth rates of ferroelectric domains and the orientation and mobility of domain walls, whereas dislocations exert a weak pinning force on domain wall motion.