Pinning of domain walls by strontium layer in BaTiO3 perovskite: an atomic-scale study

TL;DR

This study uses atomistic simulations to demonstrate that Sr inclusions in BaTiO3 act as pinning centers for domain walls, increasing energy barriers and affecting polarization, with validation through molecular dynamics.

Contribution

The paper provides the first atomic-scale evidence that Sr inclusions can pin ferroelectric domain walls in BaTiO3, linking local polarization changes to pinning effects.

Findings

Sr inclusions increase energy barriers for domain wall movement.

Pinning centers are linked to local polarization enhancement.

Molecular dynamics confirm field-driven domain wall behavior.

Abstract

We use atomistic simulations to study the interactions between two-dimensional domain walls and Sr inclusions in the prototypical ferroelectric BaTiO$_3$. Based on nudged elastic band calculations we predict that the energy barrier for domain wall movement increases in the vicinity of small planar Sr inclusions which may act as pinning centers. We link this observation to the local increase in polarization by larger oxygen off-centering and validate our predictions by molecular dynamics simulations of field-driven domain walls at finite temperatures.