Xiao-Jie LIU
Beijing Computational Science Research Center
Abstract:  We present a systematic study of metal adatom adsorption on graphene by ab initio calculations. The calculations cover alkali metals, sp-simple metals, 3d and group 10 transition metals, noble metals, as well as rare earth metals. The correlation between the adatom adsorption properties and the growth morphology of the metals on graphene is also investigated. We show that the growth morphology is related to the ratio of the adsorption energy to the bulk cohesive energy (Ea/Ec) of the metals and the diffusion barrier (E) of the metal adatom on graphene. The growth morphology is also affected by long rang interactions such as dipole-dipole interaction, elastic interaction or indirect electron interaction induced by metal adsorption on graphene. We also show that most of the metal nanostructures on graphene are thermally stable against coarsening. The bonding character and electron transfer between the metal adatoms and graphene were also analyzed using the recently developed quasi-atomic minimal basis set orbitals (QUAMBOs) approach. The calculations showed that the interaction between alkali-metal adatoms and graphene is ionic. For group-III metal adatom adsorptions, mixed covalent and ionic bonding is demonstrated. In comparison, transition-metal adsorption on graphene exhibits strong covalent bonding with graphene.
Location: 606 Conference Room
Date and time: Feb 17, 2012   14:30