Enhanced polarization and abnormal flexural deformation in bent freestanding perovskite oxides.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 36045121.
- Also identified by DOI 10.1038/s41467-022-32519-2 and PMC identifier 9433432.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Recent realizations of ultrathin freestanding perovskite oxides offer a unique platform to probe novel properties in two-dimensional oxides. Here, we observe a giant flexoelectric response in freestanding BiFeO<sub>3</sub> and SrTiO<sub>3</sub> in their bent state arising from strain gradients up to 3.5 × 10<sup>7</sup> m<sup>-1</sup>, suggesting a promising approach for realizing ultra-large polarizations. Additionally, a substantial change in membrane thickness is discovered in bent freestanding BiFeO<sub>3</sub>, which implies an unusual bending-expansion/shrinkage effect in the ferroelectric membrane that has never been seen before in crystalline materials. Our theoretical model reveals that this unprecedented flexural deformation within the membrane is attributable to a flexoelectricity-piezoelectricity interplay. The finding unveils intriguing nanoscale electromechanical properties and provides guidance for their practical applications in flexible nanoelectromechanical systems.