S1: Domain structures of the PTO film
S2: Schematic flowchart illustrating the procedures of fabricating the PTO nanodots array on the SRO/STO film.
S3: Domain structures of the PTO nanodots array acquired by aligning the cantilever at 0º, 45º and 90º to the [010] direction.
S4: Reciprocal space mapping of the PTO film and PTO nanodots array around the SrTiO3 (103) diffraction.
S5: HAADF-STEM image and GPA εxx (in-plane) map of a part of a PTO nanodots.
S6: Retention testing of the domain structure.