Figure 5 : Free energy change of a vacancy along inter-facet diffusion paths.

From: In-situ atomic-scale observation of irradiation-induced void formation

Figure 5

(a,b) Diffusion paths A-B-C and D-E-F with void thickness N=1, respectively. (c,d) Diffusion path A-B-C and D-E-F-G with N=3, respectively. (e,f) N=5. The vacancy inter-facet diffusion barrier along the whole diffusion path is estimated as the difference between maximum potential energy and that of the initial configuration. For example, the overall barrier for A→B→C path is determined as 0.20 eV (blue arrow), and the barrier for the reverse path C→B→A is 0.41 eV (red arrow). Note that when a void is one-atomic-layer thick (N=1), position G does not exist in the atomic configuration.