Figure 2.

Preferential directionality of graphitic planes. (a,b) Cross-sectional TEM images of an NG carbon film directly on SiO₂ at two different magnifications. The Ni clusters inside the NG carbon film are marked with dashed yellow lines. (c) Cross-sectional TEM image of an NG carbon film on hBN, showing ring-like graphitic planes with random orientations within the film. Scale bars in TEM images are 20 nm. Example optical images of amorphous carbon islands on (d) SiO₂ and (f) hBN. The optical images of the same islands after graphitization on (e) SiO₂ and (g) hBN. Scale bars in optical images are 30 µm.