Pinning of a ferroelectric Bloch wall at a paraelectric layer.

Vilgelmina Stepkova,Jiří Hlinka

doi:10.3762/bjnano.9.220

Abstract

The phase-field simulations of ferroelectric Bloch domain walls in BaTiO3–SrTiO3 crystalline superlattices performed in this study suggest that a paraelectric layer with a thickness comparable to the thickness of the domain wall itself can act as an efficient pinning layer. At the same time, such a layer facilitates the possibility to switch domain wall helicity by an external electric field or even to completely change the characteristic structure of a ferroelectric Bloch wall passing through it. Thus, ferroelectric Bloch domain walls are shown to be ideal nanoscale objects with switchable properties. The reported results hint towards the possibility to exploit ferroelectric domain wall interaction with simple nanoscale devices.

Highlights

Nanometer-scale mixtures of paraelectric and ferroelectric materials in disordered solid solutions or in very fine artificial crystalline superlattices often show qualitatively similar domain phenomena as the parent ferroelectric materials
In order to assess the interaction of Bloch walls with material inhomogeneities, we have explored the limiting case of ferroelectric Bloch walls encountering a layer of paraelectric material by means of phase-field simulation
Since the Bloch character is strongly suppressed when the domain wall is right at the SrTiO3 layer, the layer can facilitate selection of the sign of the Pt component, and selection of the sign of its helicity

Summary

Introduction

Nanometer-scale mixtures of paraelectric and ferroelectric materials in disordered solid solutions or in very fine artificial crystalline superlattices often show qualitatively similar domain phenomena as the parent ferroelectric materials. This result could be possibly used to set or modify the helicity of Bloch walls passing through conveniently placed paraelectric gate layers in future domain-wall-based devices.

Results

Conclusion