Polarization dependent chemistry of ferroelectric BaTiO3 (001) domains

TL;DR

This study combines theoretical and experimental approaches to show that oxygen vacancies on BaTiO3 (001) surfaces influence domain polarization, favoring inward pointing polarization and affecting surface chemistry.

Contribution

It demonstrates how surface oxygen vacancies stabilize inward polarization in BaTiO3, integrating density functional theory with microscopy measurements.

Findings

Oxygen vacancies favor inward polarization in BaTiO3 (001)

Theoretical predictions are confirmed by microscopy experiments

Surface chemistry impacts ferroelectric domain stability

Abstract

Recent works suggest that the surface chemistry, in particular, the presence of oxygen vacancies can affect the polarization in a ferroelectric material. This should, in turn, influence the domain ordering driven by the need to screen the depolarizing field. Here we show using density functional theory that the presence of oxygen vacancies at the surface of BaTiO3 (001) preferentially stabilizes an inward pointing, P-, polarization. Mirror electron microscopy measurements of the domain ordering confirm the theoretical results.