Polarization Enhancement in Short Period Superlattices via Interfacial Intermixing

TL;DR

This study demonstrates that interfacial intermixing in short period PbTiO₃/SrTiO₃ superlattices significantly enhances polarization, offering insights for ferroelectric device design through first-principles calculations.

Contribution

It reveals that interfacial intermixing boosts polarization in superlattices by affecting cation off-centering, providing a general framework for multicomponent ferroelectric structures.

Findings

Interfacial intermixing increases superlattice polarization.

Pb and Sr cation off-centering correlates with polarization enhancement.

The results are applicable to a wide range of multicomponent superlattices.

Abstract

The effect of intermixing at the interface of short period PbTiO$_3$/SrTiO$_3$ superlattices is studied using first-principles density functional theory. The results indicate that interfacial intermixing significantly enhances the polarization within the superlattice. This enhancement is directly related to the off-centering of Pb and Sr cations and can be explained through a discussion of interacting dipoles. This picture should be general for a wide range of multicomponent superlattices and may have important consequences for the design of ferroelectric devices.