Suppressing The Ferroelectric Switching Barrier in Hybrid Improper Ferroelectrics

TL;DR

This study demonstrates that biaxial strain can effectively reduce the ferroelectric switching barrier in hybrid improper ferroelectrics, enabling easier polarization switching for technological applications.

Contribution

It reveals how biaxial strain influences the switching barrier and identifies phase transition regions that suppress the barrier in Ruddlesden-Popper oxides.

Findings

Biaxial strain significantly lowers the switching barrier.

Strain-induced phase transitions to nonpolar phases explain barrier suppression.

A phase diagram region where the barrier is minimized was identified.

Abstract

Integration of ferroelectric materials into novel technological applications requires low coercive field materials, and consequently, design strategies to reduce the ferroelectric switching barriers. In this first principles study, we show that biaxial strain, which has a strong effect on the ferroelectric ground states, can also be used to tune the switching barrier of hybrid improper ferroelectric Ruddlesden-Popper oxides. We identify the region of the strain -- tolerance factor phase diagram where this intrinsic barrier is suppressed, and show that it can be explained in relation to strain induced phase transitions to nonpolar phases.