Controlled Smooth Edge Formation of Graphene Nanoribbons
  We report energy estimated to dissociate a C-C bond of a graphene sheet to form nanoribbons of armchair and zigzag configurations using first principles calculations. For the ground state energy calculations, the configurations considered are with spin, and without spin polarization. It is observed that the energy required to dissociate a C-C bond of a graphene sheet to form zigzag configuration is higher than that of armchair configuration for both spin polarized state, as well as non-spin polarized state. Therefore, formation of smooth edged graphene nanoribbons along the crystallographic directions might be engineered by a control over energy. 
Deepika, T.J. Dhilip Kumar, Nitin K. Goel, Rakesh Kumar
cond-mat.mtrl-sci cond-mat.mes-hall