Electronic and Magnetic Properties of Co‐Decorated Molecular Organic Network Adsorbed on Graphene

Abstract

First‐principles calculations based on density functional theory (DFT) are performed for investigating the electronic and magnetic properties of a heterostructure formed by Co‐decorated trimesic acid (TMA) self‐assembling network (SAN) adsorbed on graphene. The concentration and spatial position of Co adatom on graphene is regulated by the architecture of SAN. The obtained optimized geometry shows that Co adatom ends up at the top of a C atom on graphene in the heterostructure. The spin‐polarized calculations upon Co‐SAN/G, illustrate that Co adsorption on top site, which is favored by the self‐assembling network, causes an alternating change in the local density of states (LDOS) of graphene that consequently gives rise to sublattice symmetry‐breaking effects reflected in the different gap opening at K valleys. It is demonstrated that a single Co atom adsorbed on top of a C atom on graphene generates similar physical properties as Co‐SAN/G and, in fact, the SAN acts as a template for patterning Co on graphene without interfering with the magnetic properties originated from the adsorbate. Furthermore, Co atoms in the Co‐SAN/G structure, which are localized on just one sublattice type and separated by 10 Å in a triangular lattice, constitute ferromagnetically aligned spin centers.