First-principles study of epitaxial strain in perovskites

TL;DR

This study uses first-principles calculations to analyze how in-plane epitaxial strain influences the structure and polarization of various perovskite oxides, aiding in the prediction of thin film properties.

Contribution

It extends a first-principles method to systematically examine strain effects on multiple perovskites, providing insights into their structural and polarization responses.

Findings

Epitaxial strain significantly alters perovskite structures.

Polarization can be tuned via strain in these materials.

Normal stress effects are also characterized.

Abstract

Using an extension of a first-principles method developed by King-Smith and Vanderbilt [Phys. Rev. B {\bf 49}, 5828 (1994)], we investigate the effects of in-plane epitaxial strain on the ground-state structure and polarization of eight perovskite oxides: BaTiO$_3$, SrTiO$_3$, CaTiO$_3$, KNbO$_3$, NaNbO$_3$, PbTiO$_3$, PbZrO$_3$, and BaZrO$_3$. In addition, we investigate the effects of a nonzero normal stress. The results are shown to be useful in predicting the structure and polarization of perovskite oxide thin films and superlattices.