论文标题
静电效应对压电增强力显微镜中的场外铁电磁滞回路
Electrostatic effect on off-field ferroelectric hysteresis loop in piezoresponse force microscopy
论文作者
论文摘要
通过在样品表面上检测局部机电响应，可以广泛利用压电力显微镜（PFM）作为多功能和必不可少的工具来理解和分析纳米级铁 - /压电性特性。但是，已经发现机电反应不仅起源于压电性，而且还来自其他因素，例如静电效应。在这项研究中，我们通过在测量过程中将外部电压施加到底部电极，探讨了野外PFM磁滞回路对表面电位诱导的静电效应的依赖性。我们通过将表面电势等同于直流电压波形变化来简化情况，并预测表面电位诱导的静电效应对PFM磁滞回路的贡献。实验结果近似与我们的预测 - 强制电压与表面电位线性降低，而由于铁电薄膜的相对较大的压电系数，饱和振幅和压电响应几乎保持恒定。
Piezoresponse force microscopy (PFM) has been extensively utilized as a versatile and an indispensable tool to understand and analyze nanoscale ferro- /piezoelectric properties by detecting the local electromechanical response on a sample surface. However, it has been discovered that the electromechanical response not only originates from piezoelectricity but also from other factors such as the electrostatic effect. In this study, we explore the dependence of off-field PFM hysteresis loops on the surface-potential-induced electrostatic effect in a prototypical ferroelectric thin film by applying an external voltage to the bottom electrode during measurement. We simplify the situation by equating the surface potential to the direct current voltage waveform variations and predicting the contribution of the surface-potential-induced electrostatic effect to the PFM hysteresis loops. The experimental results approximately match our prediction-the coercive voltage linearly decreases with the surface potential, whereas the saturated amplitude and piezoresponse remain nearly constant owing to the relatively large piezoelectric coefficient of the ferroelectric thin film.
