PNNL

Abstract

A three-dimensional phase-field model was developed for studying the domain structures and their evolution in ferroelectric islands attached onto a substrate. It simultaneously takes into account the long-range interactions such as electric and elastic interactions, substrate constraint, as well as the stress relaxation caused by the surfaces of an island. As an example, we studied the domain structures of PbZr0.2Ti0.8O3 islands. It was demonstrated that the domain structures of ferroelectric islands could be dramatically different from those of continuous thin films due to the relief of substrate constraint. The stress distribution inside islands is highly dependent on the aspect ratio, i.e., lateral dimension over island thickness, which provides us a new way for engineering the domain structures of ferroelectric materials. The effect of electrostatic energy on the domain structures of ferroelectric islands was also discussed.