Artificial piezoelectricity in centrosymmetric SrTiO3

TL;DR

This paper demonstrates that defect engineering, specifically oxygen vacancy migration, can induce significant piezoelectricity in centrosymmetric SrTiO3, opening new avenues for designing smart materials.

Contribution

It reports the creation of a defect-induced piezoelectric layer in SrTiO3, a centrosymmetric material, verified by time-resolved X-ray diffraction, a novel approach in this context.

Findings

Piezoelectricity is induced by oxygen vacancy migration.

The effect's magnitude is comparable to ferroelectric materials.

Artificial defect-mediated piezoelectricity offers new material design strategies.

Abstract

Defect engineering is an effective and powerful tool to control existing material properties and create completely new ones, which are symmetry-forbidden in a defect-free crystal. This letter reports on the creation of piezoelectrically active near-surface layer of centrosymmetric SrTiO3, modified by the electric field-induced migration of oxygen vacancies. We provide the unequivocal proof of piezoelectricity through the stroboscopic time-resolved X-ray diffraction under alternating electric field. The magnitude of the discovered piezoelectric effect is comparable with the bulk piezoelectric effect in commercial ferroelectric materials. Such artificially formed defect-mediated piezoelectricity can be important as an alternative road for smart materials design.