Field-induced vortices in weakly anisotropic ferroelectrics

TL;DR

This paper investigates a novel polarization switching mechanism in weakly anisotropic ferroelectrics, where vortex formation, rather than traditional domain growth, induces switching, supported by theoretical modeling and experimental consistency.

Contribution

It introduces vortex formation as an alternative polarization switching mechanism in ferroelectrics, supported by Ginzburg-Landau-Khalatnikov modeling and experimental correlation.

Findings

Vortex states can form during polarization switching in ferroelectric nano-capacitors.

The vortex-induced switching mechanism aligns with recent simulations and experiments.

Vortex formation offers an effective switching pathway in weakly anisotropic ferroelectrics.

Abstract

In the micro- and nanoscale ferroelectric samples, the formation and the growth of domains are the usual stages of the polarization switching mechanism. By assuming the weak polarization anisotropy and by solving the Ginzburg-Landau-Khalatnikov equation we have explored an alternative mechanism which consists in ferroelectric switching induced by vortex formation. We have studied the polarization dynamics inside a ferroelectric circular capacitor where switching leads to formation of a metastable vortex state with a rotational motion of polarization. Our results are consistent with recent first-principa simulations [I. I. Naumov and H. X. Fu, Phys. Rev. Lett. 98, 077603 (2007)] and with experiments in PbZr0.2Ti0.8O3 [A.Gruverman et al, J. Phys. Condens. Matter 20 342201(2008)] and demonstrate that vortex induced polarization switching can be the effective mechanism for circular nano-capacitors.