Mechanically induced ferroelectric switching in BaTiO3 thin films
Mechanically induced ferroelectric switching in BaTiO3 thin films
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DOI：
10.1016/j.actamat.2020.04.032
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发表时间：
2020-07-01
期刊：
影响因子：
9.4
通讯作者：
Chen, Long-Qing
中科院分区：
文献类型：
--
作者：
Wang, Bo;Lu, Haidong;Chen, Long-Qing
在原子力显微镜 (AFM) 尖端下通过机械力反转或切换铁电薄膜的极化的能力提供了无电压控制铁电的令人兴奋的可能性。表征这种转换过程的重要指标之一是反转极化所需的临界力 F-c。然而，实验测量的F-c值显示出很大的不确定性，即使对于相同的铁电薄膜也有很大的差异。在这里，我们使用 BaTiO3 薄膜作为模型系统，结合基于 AFM 的实验和相场模拟来系统地评估 F-c。我们特别研究了 AFM 尖端半径、失配应变和薄膜厚度对 F-c 的影响以及挠曲电效应和压电效应之间的相互作用。这项工作为机械感应铁电开关的机制和控制提供了更深入的理解，从而为探索基于机械开关的潜在铁电纳米器件提供了指导。 (C) 2020 年由 Elsevier Ltd 代表 Acta Materialia Inc. 发布。
The ability to reverse or switch the polarization of a ferroelectric thin film through a mechanical force under an atomic force microscopy (AFM) tip offers the exciting possibility of a voltage-free control of ferroelectricity. One of the important metrics for characterizing such a switching process is the critical force F-c required to reverse a polarization. However, the experimentally measured values of F-c display a large uncertainty and vary significantly even for the same ferroelectric film. Here, using BaTiO3 thin films as a model system, we systematically evaluate F-c using a combination of AFM-based experiments and phase-field simulations. In particular, we study the influence of the AFM tip radius, misfit strain, and film thickness on F-c as well as the interplay between the flexoelectric and piezoelectric effects. This work provides a deeper understanding on the mechanism and control of mechanically induced ferroelectric switching and thus guidance for exploring potential ferroelectric-based nanodevices based on mechanical switching. (C) 2020 Published by Elsevier Ltd on behalf of Acta Materialia Inc.