Surface breakdown dynamics of carbon nanocapsules.

The structural variation in a single-molecule junction consisting of a hollow multi-walled carbon nanocapsule sandwiched between two gold electrodes during the breakdown of the outermost wall layer was observed in situ by high-resolution transmission electron microscopy. Simultaneously, the current-voltage curve of the junction was measured. The differential conductance of the junction decreased discontinuously from 1G(0) (where G(0) = 2e(2)/h is the conductance quantum, e is the electron charge and h is Planck's constant) to 0.5 G(0) and then to 0.2G(0) when the total number of wall layers decreased from four to three owing to the breakdown of the outermost layer. The maximum current decreased by 19 microA when the differential conductance decreased discontinuously. Our direct observation of the correlation between the atomistic structure and the conductance provides evidence for electron transport through several layers of the multi-walled nanocapsule, similar to that through carbon nanotubes with their surface in contact with electrodes.