First-Principles Bulk-Layer Model for Dielectric and Piezoelectric Responses in Superlattices

TL;DR

This paper extends a first-principles bulk-layer model to predict dielectric and piezoelectric properties in superlattices, demonstrating its accuracy and potential for designing advanced functional materials.

Contribution

The work introduces an extension of the bulk-layer model to accurately predict dielectric and piezoelectric responses in superlattices, enabling efficient materials design.

Findings

Bulk-layer model closely matches first-principles calculations for superlattices.

Model effectively captures interface and finite size effects.

Foundation for data-driven superlattice design methods.

Abstract

In the first-principles bulk-layer model the superlattice structure and polarization are determined by first-principles computation of the bulk responses of the constituents to the electrical and mechanical boundary conditions in an insulating superlattice. In this work the model is extended to predict functional properties, specifically dielectric permittivity and piezoelectric response. A detailed comparison between the bulk-layer model and full first-principles calculations for three sets of perovskite oxide superlattices, PbTiO$_3$/BaTiO$_3$, BaTiO$_3$/SrTiO$_3$ and PbTiO$_3$/SrTiO$_3$, is presented. The bulk-layer model is shown to give an excellent first approximation to these important functional properties, and to allow for the identification and investigation of additional physics, including interface reconstruction and finite size effects. Technical issues in the generation of the necessary data for constituent compounds are addressed. These results form the foundation for a powerful data-driven method to facilitate discovery and design of superlattice systems with enhanced and tunable polarization, dielectric permittivity, and piezoelectric response.