biostudies-literatureUnknown16(1)Sun YThis study demonstrates the use of oxygen vacancy-induced planar defects to significantly enhance electrical polarization through a local flexoelectric effect. By introducing an appropriate level of aliovalent dopants, numerous local planar defects are induced in (Bi_0.5, Na_0.5)TiO₃-based thin films. These defects, identified as oxygen-deficient structures through direct visualization of oxygen atoms and oxygen vacancies using integrated differential phase-contrast microscopy, result in the formation of head-to-head domain structures. Geometric phase analysis confirms that these structures exhibit a substantial local strain gradient of up to 10⁹m^-1, contributing significantly to the flexoelectric polarization. Consequently, a giant maxNature communications10589https://www.ebi.ac.uk/biostudies/studies/S-EPMC12658055biostudies-literatureFlexoelectricity-driven giant polarization in (Bi, Na)TiO<sub>3</sub>-based ferroelectric thin films.PMC12658055Cazorla CYang JGeng XZhang JChang SLYHuang HWang DLou XWang HZhang SSun YNiu RChen ZTang SGuo CSong ZfalseFlexoelectricity-driven giant polarization in (Bi, Na)TiO<sub>3</sub>-based ferroelectric thin films.This study demonstrates the use of oxygen vacancy-induced planar defects to significantly enhance electrical polarization through a local flexoelectric effect. By introducing an appropriate level of aliovalent dopants, numerous local planar defects are induced in (Bi_0.5, Na_0.5)TiO₃-based thin films. These defects, identified as oxygen-deficient structures through direct visualization of oxygen atoms and oxygen vacancies using integrated differential phase-contrast microscopy, result in the formation of head-to-head domain structures. Geometric phase analysis confirms that these structures exhibit a substantial local strain gradient of up to 10⁹m^-1, contributing significantly to the flexoelectric polarization. Consequently, a giant max2025-01-01T00:00:00Z2025 Nov2026-06-05T21:31:23.621Z2026-05-22T03:14:50.812ZS-EPMC126580554129839110.1038/s41467-025-65610-5