标题： 在纳米尺度上测量直接flexoelectricity 显示英文标题

标题： Measuring direct flexoelectricity at the nanoscale

摘要： 压电弹性是所有介电材料的特性，其中不均匀应变会引发电极化。 这种效应在纳米尺度尤为显著，因为在该尺度上可以获得更大的应变梯度。 虽然已经在毫米尺度系统中测量到了压电弹性电荷，但尚未实现对纳米厚度材料的直接测量。 鉴于压电弹性最显著的应用之一是在纳米电子机械系统（NEMS）中，确认这些尺度上的效应存在及其大小至关重要。 本研究首次使用具有50纳米铪氧化物层的悬臂梁，对纳米厚度材料中压电弹性产生的电荷（直接效应）进行了测量。 我们确认，从这些测量中估算出的压电弹性系数与通过压电弹性逆效应的互补实验获得的值一致。 此外，通过改变悬臂梁的几何结构（改变悬臂梁的宽度），我们展示了有效压电弹性系数提高了40%，这是由不同的压电弹性张量分量之间的相互作用所解释的。 这些发现不仅验证了纳米尺度上压电弹性效应的存在，还为NEMS/MEMS器件中运动的完整压电弹性转换提供了可能性。 显示英文摘要

摘要： Flexoelectricity is a property of all dielectric materials, where inhomogeneous strain induces electrical polarization. This effect becomes particularly prominent at the nanoscale where larger strain gradients can be obtained. While flexoelectric charges have been measured in mm-scale systems, direct measurements in nanoscale-thickness materials have not yet been achieved. Given that one of the most prominent applications of flexoelectricity is in nano-electro-mechanical systems (NEMS), confirming the presence and magnitude of the effect at these scales is essential. This study presents the first-ever measurements of flexoelectric-generated charges (direct effect) in nanoscale-thickness materials, using cantilevers with a 50 nm hafnium oxide layer. We confirm that the estimated flexoelectric coefficient from said measurements aligns with the values obtained from complementary experiments using the flexoelectric inverse effect. Additionally, by changing the cantilever geometry (modifying the width of the cantilevers), we demonstrate a 40% increase in the effective flexoelectric coefficient, explained by the interplay of different flexoelectric tensor components. These findings not only validate the presence of flexoelectric effects at the nanoscale but also open the possibility for full flexoelectric transduction of the motion in NEMS/MEMS devices.