Fig. 2: Deformations at superdomain junctions.

a Lattice schematic of a twin wall. The twin domains are indicated in red and blue, respectively, with their polarization labeled by arrows. The original lattice without twinning is shown in dashed blue lines, illustrating a 5° mismatch of the [110] directions. b The difference of diffraction patterns from neighboring stripe domains, confirming the 5° rotation. c, d Ferroelastic strain (c) and rotation (d) maps at a superdomain boundary where both needle tip morphology and “T” junctions coexist. Polarization directions are indicated by arrows in (c), and a deformed “T” junction is circled. Between two dotted lines is a transition zone where both needle tips and “T” junctions are observed. The black and blue arrows in (d) highlight the differences in lattice rotation between needle tip structures and “T” junctions. (Scale bar: 200 nm) (e) Line profiles of the continuous lattice rotation from the black and blue arrows in (d) respectively. f Statistics of deformed length depending on the in-plane width ratio (b/a) of the stripe domains. The gray dotted lines show the transition zone. Inset: schematics of the measurements on widths (a and b) and deformed lengths (d).