Engineering polarization rotation in a ferroelectric superlattice

TL;DR

This paper demonstrates how engineering layer thicknesses in ferroelectric superlattices can induce polarization rotation, significantly enhancing piezoelectric response and dielectric tunability under ambient conditions.

Contribution

The study introduces a novel method of inducing polarization rotation in ferroelectric superlattices by adjusting layer thicknesses, leading to improved functional properties.

Findings

Enhanced piezoelectric response observed

Polarization rotation confirmed by x-ray diffraction

Functional property changes detected in electrical measurements

Abstract

A key property that drives research in ferroelectric perovskite oxides is their strong piezoelectric response in which an electric field is induced by an applied strain, and vice-versa for the converse piezoelectric effect. We have achieved an experimental enhancement of the piezoelectric response and dielectric tunability in artificially layered epitaxial PbTiO$_{3}$/CaTiO$_{3}$ superlattices through an engineered rotation of the polarization direction. As the relative layer thicknesses within the superlattice were changed from sample to sample we found evidence for polarization rotation in multiple x-ray diffraction measurements. Associated changes in functional properties were seen in electrical measurements and piezoforce microscopy. The results demonstrate a new approach to inducing polarization rotation under ambient conditions in an artificially layered thin film.