Identifying intrinsic ferroelectricity of thin film with piezoresponse force microscopy
Identifying intrinsic ferroelectricity of thin film with piezoresponse force microscopy
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用压响应力显微镜识别薄膜的本征铁电性
DOI：
10.1063/1.4999199
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发表时间：
2017-09-01
期刊：
影响因子：
1.6
通讯作者：
Chu, Jun-Hao
中科院分区：
文献类型：
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作者：
Guan, Zhao;Jiang, Zhen-Zheng;Chu, Jun-Hao
压电响应力显微镜（PFM）是一种通过测量铁电薄膜的动态机电响应来表征铁电薄膜的有力技术。铁电性通常由PFM磁滞回线和极化前后PFM图像的180 °相位差来证明。然而，最近在许多非铁电体中也发现了这种类似铁电的行为。因此，在各种薄膜中识别本征铁电性仍然是一个挑战。在这里，使用PFM，我们系统地研究了铁电薄膜的机电响应与快速（钛酸钡）和慢速（PVDF）的开关动力学，也在非铁电（Al2O3）薄膜。研究发现，交流电压（Vac）和脉冲直流电压（Vdc）在PFM测量中起着重要的作用。当Vac振幅高于一个明确的阈值电压（Vc），崩溃的PFM磁滞回线观察到快速开关动态的薄膜。通过测量金属烤瓷冠的硬度，
Piezoresponse force microscopy (PFM) is a powerful technique to characterize ferroelectric thin films by measuring the dynamic electromechanical response. The ferroelectricity is commonly demonstrated by the PFM hysteresis loops and a 180o phase difference of PFM images before and after poling. Such ferroelectric-like behaviors, however, recently are also found in many non-ferroelectrics. Consequently, it is still a challenge to identify intrinsic ferroelectricity in various kinds of thin films. Here, using PFM, we systematically studied the electromechanical responses in ferroelectric thin films with fast (BaTiO3) and slow (PVDF) switch dynamics, and also in the non-ferroelectric (Al2O3) thin films. It is found that both of the ac voltage (Vac) and pulsed dc voltage (Vdc) play an important role in the PFM measurement. When the Vac amplitude is higher than a explicit threshold voltage (Vc), collapse of the PFM hysteresis loops is observed for the films with fast switch dynamics. By measuring PFM hysteresi...