First-principles bulk-layer model for dielectric and piezoelectric responses in superlattices

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, PbTiO3/BaTiO3, BaTiO3/SrTiO3 and PbTiO3/SrTiO3, 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.

Structural and electronic properties of monodomain ultrathin PbTiO3/SrTiO3/PbTiO3/SrRuO3 heterostructures: A first-principles approach

“…22 For the first PbTiO 3 layer (between the SrTiO 3 spacer and the SrRuO 3 electrode), the tetragonality is almost constant, independent of the value of Q. This is in good agreement with the bulk calculations by Bonini et al 45 where, within this regime of electric displacements, the out-of-plane lattice constant of bulk PbTiO 3 does not change appreciably (see the top panel of Fig. 1 of Ref.…”

“…1 of Ref. 45). For the second PbTiO 3 layer (between the SrTiO 3 spacer and vacuum), the average tetragonality drops from the undoped system to the charged configuration with Q ¼ +0:05 and then progressively increases with the external charge, as the polarization-induced effect become more dominant over the surface-induced influence.…”