Bonding and charge transfer by metal adatom adsorption on graphene

TitleBonding and charge transfer by metal adatom adsorption on graphene
Publication TypeJournal Article
Year of Publication2011
AuthorsLiu XJ, Wang CZ, Yao YX, Lu WC, Hupalo M, Tringides MC, Ho KM
Journal TitlePhysical Review B
Volume83
Pages235411
Date Published06/10
ISBN Number1098-0121
Accession NumberISI:000291462100012
Keywordsatoms, augmented-wave method, basis-set, initio, total-energy calculations
Abstract

Adsorption of the alkali-, group-III, and 3d-transition-metal adatoms (Na, K, Al, In, V, Fe, Co, and Ni) on graphene was studied systematically by first-principles calculations. The bonding character and electron transfer between the metal adatoms and graphene were 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 and has minimal effects on the lattice and electronic states of the graphene layer, in agreement with previous calculations. For group-III metal adatom adsorptions, mixed covalent and ionic bonding is demonstrated. In comparison, 3d-transition-metal adsorption on graphene exhibits strong covalent bonding with graphene. The majority of the contributions to the covalent bonds are from strong hybridization between the d(x2-y2) and d(yz) orbitals of the 3d-transition-metal adatoms and p(z) orbitals of the carbon atoms. The strong covalent bonds cause large in-plane lattice distortions in the graphene layer. Charge redistributions upon adsorptions also induce significant electric dipole moments and affect the magnetic moments.

URL<Go to ISI>://000291462100012
DOI10.1103/PhysRevB.83.235411
Alternate JournalPhys Rev BPhys Rev B