Figure 3
From: Nucleation and growth of primary nanostructures in SrTiO3 homoepitaxy
STM images for defect formations in the initial growth stage. (a) to (c) 20 × 20-nm2 STM images showing the formation of defects in the substrate surfaces of 1-, 2-, and 3-p samples, respectively. All STM images were obtained with V S = 2.0 V and I set = 50 pA. The inset of (a) shows an STM image of the same area with the same length scale that was obtained using a different tip. The gray arrows indicate large white structures, which are 1-uc-high SrTiO3 islands. The red (blue) curve in (d) shows the STM apparent height profile along the red (blue) line in (a) ((b)). (e) FT power spectrum map of (a). The yellow circles show bright spots in the FT power spectrum at (1/2 0), which are indicative of 2 × 2 RC. (f) FT power spectrum map of (c). The bright spots indicated by the green circles at (1/4 0) correspond to a periodicity of 4 uc along the directions of crystal symmetry.