Tunneling effect of graphite is studied by atomic force microscopy. The tunneling current in the gap between a conductive tip and a newly cleaved graphite surface at a given voltage keeps almost constant when the gap-distance varies within 1 μm, which cannot be explained by the commonly...

Spin-polarized density functional theory has been used to study the effects of vacancy defects on the magnetic properties of graphene. Structural optimization shows that introducing a carbon vacancy cluster into a graphene sheet changes the spatial distribution of the neighbor atoms,...