Dynamic flexoelectric effect in perovskites from first principles calculations

TL;DR

This paper presents a first-principles method to evaluate the dynamic flexoelectric effect in perovskites, showing it is comparable to the static effect and proposing a way to analyze phonon spectra for experimental insights.

Contribution

It introduces a novel ab initio approach to quantify dynamic flexoelectricity and links theoretical calculations with experimental phonon spectrum analysis.

Findings

Dynamic flexoelectric effect is comparable to static effect.

Proposed a method to evaluate flexoelectric effects from phonon spectra.

Method enables experimental characterization of bulk flexoelectricity.

Abstract

Using the dynamical matrix of a crystal obtained from ab initio calculations, we have evaluated for the first time the strength of the dynamic flexoelectric effect and found it comparable to that of the static bulk flexoelectric effect, in agreement with earlier order-of-magnitude estimates. We also proposed a method of evaluation of these effects directly from the simulated phonon spectra. This method can also be applied to the analysis of the experimental phonon spectra, being currently the only one enabling experimental characterization of the static bulk flexoelectric effect.