Analytical method to determine flexoelectric coupling coefficient at nanoscale

TL;DR

This paper proposes an analytical method using nanocompression to measure the flexoelectric coupling coefficient at the nanoscale, leveraging stiffness softening in dielectric nano-cone-frustum without direct polarization measurement.

Contribution

It introduces a novel analytical approach for flexoelectric measurement at nanoscale based on mechanical stiffness changes, avoiding complex electric measurements.

Findings

Flexoelectricity causes stiffness softening in dielectric nano-cone-frustum.

The softening effect increases with decreasing sample size and larger cone angles.

The method simplifies nanoscale flexoelectric measurement and device design.

Abstract

Flexoelectricity is defined as the coupling between strain gradient and polarization, which is expected to be remarkable at nanoscale. However, measuring the flexoelectricity at nanoscale is challenging. In the present work, an analytical method for measuring the flexoelectric coupling coefficient based on nanocompression technique is proposed. It is found that the flexoelectricity can induce stiffness softening of dielectric nano-cone-frustum. This phenomenon becomes more significant when the sample size decreases or the half cone angle increases. This method avoids measuring the electric polarization or current at nanoscale with dynamical loading, which can be beneficial to the flexoelectric measurement at nanoscale and design of flexoelectric nanodevices.