Flexoelectric Effect at the Nanoscale

Abstract

Flexoelectric effect Flexoelectric effectat nanoscaleis a universal electromechanical Nanoscaleflexoelectric effect atcoupling effect in solids. Nevertheless, it has been ignored for a long time, due to the usual small strain gradients in materials. The case is different for nanomaterials, where strain gradients can usually reach to the order of 106 m−1. Moreover, as the flexoelectric effect scales with dielectric susceptibility, it can be much more apparent in materials with higher dielectric constants, such as ferroelectrics. Due to this reason, increasing attention has been attracted on the flexoelectric effect in nanomaterials (with ferroelectrics as the representatives) during the past few years. The large flexoelectric effect in nanomaterials not only makes them promising candidates to design novel electromechanical nanodevices but also strongly modifies many material properties such as polarization switching, ferroelectric domains and domain walls, polarization-mediated electronic transport effects, etc. Focusing on flexoelectric effect at the nanoscale and with ferroelectrics as the representatives, this chapter aims to provide an overview of this rapidly growing field, including the theoretical models and experimental characterization methods of flexoelectric effect, the recent important progress of flexoelectric effect, as well as the potential applications.