FIG. 4: (a) SEM image showing textures near sample edge; (b) zoom-in SEM image in red rect- angular in (a); (c) STM image showing the observation of dislocations (horizontal arrow), which were also seen in (a) and (b); (d) and (e) STM images of corresponding positions indicated with dashed arrows in (a) and (b) respectively. All the STM images, (c)-(e), have the same dimensions of 300 nm × 300 nm. 6