Vibrational properties of graphene nano-flakes

One of the most fascinating property of carbon (a Group IV element) is its unique chemical bonding flexibility which is able to produce many different molecular compounds and crystalline solids. Carbon has four valence electrons which tend to interact with each other to produce various kinds of carbon allotropes. Therefore, the allotropes of carbon span all three spatial dimensions from 0D fullerenes, 1D carbon nanotubes, 2D graphene to 3D graphite and diamond with very different physical properties, e.g. graphite is an insulator while diamond is a conductor