Piezoelectricity usually accompanies with flexoelectricity in polar materials which is the linear response of polarization to a strain gradient. Therefore, it is hard to eliminate piezoelectric effect in determination of pure flexoelectric response. In this work, we propose an analytical method to characterize the flexoelectric coefficient quantitatively at nanoscale in piezoelectric materials by screening piezoelectricity. Our results show that the flexoelectricity reduces the nanopillar stiffness while the piezoelectricity enhances it. With careful design of the shape of the nanopillars and measuring their stiffness difference, the flexoelectric coefficient can be obtained with the piezoelectric contribution eliminated completely. This approach avoids the measurement of electrical properties with dynamic load, which helps to reduce the challenge of flexoelectric measurement at nanoscale. Our work will be beneficial to quantitative characterization of flexoelectric properties and design of flexoelectric devices at nanoscale.

中文翻译：

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在纳米尺度确定挠曲电系数中筛选压电性

在极性材料中，压电通常伴随着挠电性，这是极化对应变梯度的线性响应。因此，在确定纯挠曲电响应时，很难消除压电效应。在这项工作中，我们提出了一种通过筛选压电性来定量表征压电材料中纳米级挠曲电系数的分析方法。我们的结果表明，挠曲电性降低了纳米柱刚度，而压电性增强了它。通过仔细设计纳米柱的形状并测量它们的刚度差异，可以在完全消除压电贡献的情况下获得挠曲电系数。这种方法避免了用动态负载测量电气特性，这有助于减少纳米级柔性电测量的挑战。我们的工作将有利于柔性电性能的定量表征和纳米级柔性电器件的设计。