Figure 4.

(a) Dark field TEM images of sample B indicates the formation of self-organized dislocation network. (a1) Zoom-in TEM image of area A exhibits the nucleation of half loops. (b) The schematic diagram illustrates half loop nucleation and propagation of 60° dislocation at critical thickness along (111) plane. (c) Lomer dislocation is formed with the following reaction: $\frac{a}{2}\left[011\right]+\frac{a}{2}\left[10\overline{1}\right]=\frac{a}{2}\left[110\right]$ when two 60° dislocations on $\left(111\right)$ and $\left(\overline{1}\overline{1}1\right)$ planes intersect with each other.