title: Growth of metalloid aluminum clusters on graphene vacancies.
abstract: Ab initio simulations are used to show that graphene vacancy sites may offer a means of templated growth of metalloid aluminum clusters from their monohalide precursors. We present density functional theory and ab initio molecular dynamics simulations of the aluminum halide AlCl interacting with a graphene surface. Unlike a bare Al adatom, AlCl physisorbs weakly on vacancy-free graphene with little charge transfer and no hybridization with carbon orbitals. The barrier for diffusion of AlCl along the surface is negligible. Covalent bonding is seen only with vacancies and results in strong chemisorption and considerable distortion of the nearby lattice. Car-Parrinello molecular dynamics simulations of AlCl liquid around a graphene single vacancy show spontaneous metalloid cluster growth via a process of repeated insertion reactions. This suggests a means of templated cluster nucleation and growth on a carbon substrate and provides some confirmation for the role of a trivalent aluminum species in nucleating a ligated metalloid cluster from AlCl and AlBr solutions.
authors.affiliation: Department of Physics, Naval Postgraduate School, Monterey, California 93943, USA.
authors.forename: Sufian
authors.initials: S
authors.lastname: Alnemrat
authors.affiliation: Naval Surface Warfare Center, Indian Head, Maryland 20640, USA.
authors.forename: Dennis H
authors.initials: DH
authors.lastname: Mayo
authors.affiliation: Department of Chemistry, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: Samantha
authors.initials: S
authors.lastname: DeCarlo
authors.affiliation: Department of Physics, Naval Postgraduate School, Monterey, California 93943, USA.
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Hooper