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.
@article{arxiv.1605.07490,
title = {Artificial piezoelectricity in centrosymmetric SrTiO3},
author = {B. Khanbabaee and E. Mehner and C. Richter and J. Hanzig and M. Zschornak and U. Pietsch and H. Stöcker and T. Leisegang and D. C. Meyer and S. Gorfman},
journal= {arXiv preprint arXiv:1605.07490},
year = {2016}
}