Piezoelectricity in the dielectric component of nanoscale dielectric/ferroelectric superlattices

TL;DR

This study investigates the piezoelectric properties of CaTiO3 layers within CaTiO3/BaTiO3 superlattices, revealing a significant piezoelectric response consistent with theoretical predictions and elucidating the layered origin of functional properties.

Contribution

It demonstrates the piezoelectric response of CaTiO3 layers in superlattices and correlates experimental results with first-principles calculations under substrate-imposed symmetry.

Findings

CaTiO3 layers exhibit a measurable piezoelectric response.

The superlattice's piezoelectric coefficient is 54 pm/V at large strains.

Experimental results align with first-principles predictions.

Abstract

The origin of the functional properties of complex oxide superlattices can be resolved using time-resolved synchrotron x-ray diffraction into contributions from the component layers making up the repeating unit. The CaTiO3 layers of a CaTiO3/BaTiO3 superlattice have a piezoelectric response to an applied electric field, consistent with a large continuous polarization throughout the superlattice. The overall piezoelectric coefficient at large strains, 54 pm/V, agrees with first-principles predictions in which a tetragonal symmetry is imposed on the superlattice by the SrTiO3 substrate.