High field properties of typical perovskite ferroelectrics by first-principles modeling

TL;DR

This study uses first-principles calculations to explore how large electric fields influence the structural and ferroelectric properties of typical perovskite ferroelectrics, revealing polarization rotation mechanisms and material-specific responses.

Contribution

It provides new insights into the effects of high electric fields on ferroelectric materials, including estimated coercive fields and the stability of dielectric properties.

Findings

Structural parameters change significantly at large fields.

Polarization rotation model is supported for ferroelectric switching.

BaTiO3 shows stable dielectric permittivity at high fields.

Abstract

Using first-principles calculations, we estimated the impact of large applied electric E fields on the structural, dielectric, and ferroelectric properties of typical ferroelectrics. At large fields, the structural parameters change significantly, decreasing the strain between the different structural phases. This effect favours a polarization rotation model for ferroelectric switching in which the electronic polarization rotates between the directions of tetragonal, rhombohedral and orthorhombic phases. We estimate coercive fields E_c ~31 MV/m and ~52 MV/m at zero temperature for bulk ferroelectric monodomains of BaTiO3 and PbTiO3, respectively. The dielectric permittivity and tunability of BaTiO3 are the least affected at large fields, making this material attractive for applications in electronics and energy storage.