Edge-mediated dislocation processes in multishell carbon nano-onions?

We report in situ electron microscopy observations of dislocation dissociation and annihilation processes in individual nanometer-sized carbon onions. Essential for these processes is the counterintuitive motion of the 1/2 0001 edge from the outer surface to the inner region, which cross-links or unlinks a large number of shells. The correlation with atomistic simulations and analysis of the energy which separates the strain and edge components indicates that this inward glide originates in the reduction of edge with each inwards glide step, an effect specific to the spherical topology.