Extended Data Fig. 1: Microstructure of as-grown ScGaN on GaN template.
From: Electric-field-induced domain walls in wurtzite ferroelectrics
a, Schematic of the sample structure. b, Cross-sectional STEM image and corresponding elemental map, indicating uniform elemental distribution. Scale bar, 50 nm. c, The wurtzite lattice group of the ScGaN layer is further evidenced by the nanobeam electron diffraction patterns. d, High-resolution STEM images of as-grown ScGaN on GaN. Magnified images with HAADF and iDPC contrast (scale bar, 1 nm) are taken from different regions in the heterostructure as indicated in the low-magnification STEM image on the left (scale bar, 20 nm), showing uniform metal polarity in the ScGaN film before ferroelectric switching. This further supports that the N-polar regions in switched capacitors result from electric-field-induced polarity switching rather than being attributable to localized defects inherent to the material.
