fig2

Figure 2. (A) Low magnification BF-STEM image of a ($$\overline{1}$$10) FIB-prepared lamella. The dark arrow at the thin edge of the lamella points towards increasing thickness. The width of the straight dark lines is independent of specimen thickness, showing that they correspond to planes seen edge-on. The crystal orientation applies to all images in this figure. (B) Ideal ($$\overline{1}$$10) projection of BiFeO₃, where Bi atoms are presented in red, Fe blue, and O grey. The direction of the -δ_FB vector is also shown. (C) A high-resolution ABF-STEM image of a flat wall. White lines are aligned horizontally and vertically, allowing the rigid-body displacement of the domains along [110] and [001] to be seen. (D) An ADF-STEM image taken simultaneously with C). Arrows in (D) show local -δ_FB vectors, indicating the magnitude and direction of polarisation in each unit cell.