Figure 6: Domain switching kinetics in the absence of APBs in CSTO.

(a) In-plane DF-TEM images show two ferroelastic (FA(i) and FA(ii)) regions. Domain states 2− (light yellow arrow) and 1+ (red arrow) are assigned based on diffraction patterns and the assumption of a non-charged head-to-tail wall. (b) Polarization domain evolutions across a FA_tr boundary. Election beam focused at the end of a FA boundary close to the sample edge induces an electric field indicated by a red/white arrow. A polarization switching (dark grey contrast) from 1+ → 2+ in FA(i) and 2−→2+ in FA(ii) is observed. The right-side cartoon shows a schematic of the domain switching via a splitting/merging of FA_tr → FA_t+FE_r DWs. A high energy FA_tr DW becomes two DWs with lower energies; one ferroelectric FE_r DW and the other ferroelastic FA_t DW, which is consistent with our energy hierarchy. Both FA_t and FE_r DWs tend to be mobile and highly curved, which is again consistent the low energy nature of FA_t and FE_r DWs in our energy hierarchy. Cyan and blue circles denote Z₃ vortex (V) and antivortex (AV), respectively. Scale bar, 500 nm.