Atomic mechanism of polarization-controlled surface reconstruction in ferroelectric thin films.
Atomic mechanism of polarization-controlled surface reconstruction in ferroelectric thin films.
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铁电薄膜中偏振控制表面重构的原子机制
DOI：
10.1038/ncomms11318
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发表时间：
2016-04-19
影响因子：
16.6
通讯作者：
Ikuhara Y
中科院分区：
文献类型：
--
作者：
Gao P;Liu HJ;Huang YL;Chu YH;Ishikawa R;Feng B;Jiang Y;Shibata N;Wang EG;Ikuhara Y
在铁电表面，平移对称性破缺所诱导的束缚电荷应会显著改变局部原子构型。然而，由于纳米尺寸畴之间的强烈空间差异以及极化与其他结构参数之间的强相互作用，通过实验揭示铁电表面的原子结构极具挑战性。在此，我们利用环形明场成像研究了Pb(Zr₀.₂Ti₀.₈)O₃薄膜的表面结构。我们发现，在负极化表面存在六层极化受抑的原子层以及一个带电的180°畴壁；在正极化表面不存在重构；在铁弹畴的名义中性表面存在七层极化受抑的原子层以及一个带电的90°畴壁。我们的结果为铁电薄膜、细晶陶瓷和表面化学器件的工程设计提供了关键见解。此处所展示的先进方法能够极大地增进我们对氧化物表面科学的理解。
电子器件的小型化具有吸引力，但由于纳米尺度的结构变化而具有挑战性。在此，高等人报道了Pb(Zr₀.₂Ti₀.₈)O₃表面重构和异常畴壁的原子成像，为设计纳米尺度的结构变化提供了可能性。
At the ferroelectric surface, the broken translational symmetry induced bound charge should significantly alter the local atomic configurations. Experimentally revealing the atomic structure of ferroelectric surface, however, is very challenging due to the strong spatial variety between nano-sized domains, and strong interactions between the polarization and other structural parameters. Here, we study surface structures of Pb(Zr0.2Ti0.8)O3thin film by using the annular bright-field imaging. We find that six atomic layers with suppressed polarization and a charged 180° domain wall are at negatively poled surfaces, no reconstruction exists at positively poled surfaces, and seven atomic layers with suppressed polarization and a charged 90° domain wall exist at nominally neutral surfaces in ferroelastic domains. Our results provide critical insights into engineering ferroelectric thin films, fine grain ceramics and surface chemistry devices. The state-of-the-art methodology demonstrated here can greatly advance our understanding of surface science for oxides.