Using the classic ferroelectric BaTiO3 as an example, we show that the 180 degree ferroelectric domain wall, long considered to be of Ising-type and charge neural, contains both Bloch and Neel type polarization components, and is thus charged. The bound charge density at the wall may reach as high as 106~107 Cm−3. It is demonstrated that the flexoelectric effect arising from stress inhomogeneity is responsible for the additional Bloch and Neel polarization components. The magnitudes of these additional components are determined by the competing depolarization and flexoelectric fields.
@article{arxiv.1401.0194,
title = {Non-Ising Character of a Ferroelectric Wall Arises from a Flexoelectric Effect},
author = {Yijia Gu and Menglei Li and Anna N. Morozovska and Yi Wang and Eugene A. Eliseev and Venkatraman Gopalan and Long-Qing Chen},
journal= {arXiv preprint arXiv:1401.0194},
year = {2014}
}