Chemical Bonding of Transition-metal Co$_{13}$ Clusters with Graphene

TL;DR

This study uses density functional calculations to analyze how Co$_{13}$ clusters bind to graphene, revealing a preference for icosahedron-like structures with chemical bonding characteristics and stable isomer arrangements.

Contribution

It provides new insights into the preferred structures and bonding nature of Co$_{13}$ clusters on graphene, emphasizing chemical interactions over ionic bonds.

Findings

Co$_{13}$ clusters favor icosahedron-like structures on graphene.

Charge transfer between clusters and graphene is minimal, indicating chemical bonding.

The stability order of isomers remains consistent on doped graphene.

Abstract

We carried out density functional calculation to study Co$_{13}$ clusters on graphene. We deposit several free isomers in different disposition respect to hexagonal lattice nodes, studying even the $hcp$ $2d$ isomer recently obtained as the most stable one. Surprisingly, Co$_{13}$ clusters bonded to graphene prefer $icosahedron-like$ structures where the low lying isomer is much distorted, because it is linked with more bonds than in previous works. For any isomer the most stable position binds to graphene by the Co atoms that can lose electrons. We find that the charge transfers between graphene and clusters are small enough to conclude that the Co-graphene binding is not ionic-like but chemical. Besides, the same order of stability among the different isomers on doped graphene is well kept. These findings could also be of interest for magnetic clusters on graphenic nanostructures such as ribbons and nanotubes.