fig8

Figure 8. Flexoelectricity-driven polarization switching and domain tailoring in ferroelectrics. (A) Schematic illustration of AFM-tip-induced strain gradients in epitaxial BaTiO₃ thin films. (B) Free-energy landscape under a strain gradient. (C and D) AFM writing experiments for (C) creation and (D) erasure of nanoscale domain patterns using only mechanical force. (A-D) Reproduced with permission^[25]. Copyright 2012, American Association for the Advancement of Science; (E) Domain evolution in metastable CaTiO₃ after mechanical writing at an ultralow force (~100 nN). (F and G) PFM signal analysis of domain stability and storage density. (F) Cross-sectional PFM phase profiles measured after 120 min. (G) Time-dependent PFM amplitude as a function of time. (E-G) Reproduced with permission^[67]. Copyright 2022, American Physical Society; (H) Atomic-resolution strain mapping at ferroelastic twin walls in WO₃ films. (I) Scanning-tip-controlled reorientation of ferroelastic walls. (H and I) Reproduced with permission^[32]. Copyright 2020, Springer Nature. AFM: Atomic force microscopy; PFM: piezoresponse force microscopy.