ABSTRACT
Zero-spin density graphene implies the absence of free spins since, as mentioned earlier graphene belongs to species for which Na = Nß. In view of electron correlation, graphene presents a honeycomb structure of carbon atoms with local spins distributed over them. The variety of electron density of carbon atoms along edges of a graphene flake as well as perpendicular to them was clearly demonstrated by site-specific single-atom electron energy loss spectroscopy by using annular dark field mode of a low-voltage STEM. Despite numerous extraordinary properties and huge potential for various applications, one of the greatest challenges in using graphene as an electronic material is the lack of a sizable bandgap. Chemical modification of graphene is not only a subject of interesting chemistry but has been repeatedly suggested as an efficient tool for the semimetal-semiconductor transferring needed for high-performance electronics.
