Flexoelectricity in antiferroelectric ceramics

TL;DR

This study measures flexoelectricity in antiferroelectric ceramics PbZrO3 and AgNbO3 across temperatures, revealing a peak at phase transition but no anomalously high flexoelectric response, expanding understanding of these materials.

Contribution

It provides the first experimental flexoelectric measurements in antiferroelectric ceramics and links flexoelectric behavior to phase transitions.

Findings

Flexoelectricity peaks at the antiferroelectric phase transition.

No anomalously high flexoelectric response in studied materials.

Flexocoupling coefficients vary with temperature.

Abstract

Flexoelectricity (coupling between polarization and strain gradients) is a property of all dielectric materials that has been theoretically known for decades, but it is only relatively recently that it has begun to attract experimental attention. As a consequence, there are still entire families of materials whose flexoelectric performance is unknown. This is the case, for example, of antiferroelectrics: materials with an antipolar but switchable arrangement of dipoles. And yet, these materials could be flexoelectrically relevant because it has been hypothesised that the origin of their antiferroelectricity might be flexoelectric. In this work, we have measured the flexoelectricity of two different antiferroelectrics (PbZrO3 and AgNbO3) as a function of temperature, up to and beyond their Curie temperature. Neither flexoelectricity nor the flexocoupling coefficients are anomalously high, but the flexocoupling shows a sharp peak at the antiferroelectric phase transition.