First-principles studies on graphene-supported transition metal clusters

摘要

Theoretical studies on the structure, stability, and magnetic properties of icosahedral TM_(13) (TM=Fe, Co, Ni) clusters, deposited on pristine (defect free) and defective graphene sheet as well as graphene flakes, have been carried out within a gradient corrected density functional framework. The defects considered in our study include a carbon vacancy for the graphene sheet and a five-membered and a seven-membered ring structures for graphene flakes (finite graphene chunks). It is observed that the presence of defect in the substrate has a profound influence on the electronic structure and magnetic properties of graphene-transition metal complexes, thereby increasing the binding strength of the TM cluster on to the graphene substrate. Among TM_(13) clusters, Co_(13) is absorbed relatively more strongly on pristine and defective graphene as compared to Fe_(13) and Ni_(13) clusters. The adsorbed clusters show reduced magnetic moment compared to the free clusters.