Unraveling atomic-scale edge structure of nanoscale graphene islands
Through high resolution scanning tunneling microscopy measurements and first principles Density Functional Theory based calculations, a novel atomic scale edge structure was shown to be stable for graphene islands grown on cobalt surfaces. The low-coordinated carbon atom at the Klein edge structure is stabilized by interaction with the cobalt surface. This is the first demonstration, combining experiment and theory, that the interaction of the carbon atoms with a metal substrate stabilizes the low coordinated carbon edge atoms. In models for the growth of graphene on metal substrates, such low coordinated atoms at the growing edge play a special role. These results, which demonstrate such stability, will play a significant role in further development of these models and will help guide future strategies to grow graphene nanostructures with atomic scale control of edge structure.