Controlling the magnetic anisotropy of Ni cluster supported on graphene flakes with topological defects

Enhancing the magnetic anisotropy of transition metal (TM) clusters remains one of the primary objectives for applications of cluster assembled materials in high-density magnetic data storage devices. In this regard, graphene supports with topological disorder are considered as promising substrate materials for the TM clusters as defects can act as anchoring centers. Based on density functional theory for Ni clusters deposited on graphene nanoflakes, we show that magnetic anisotropy of Ni clusters can be tuned by specific topological defects in the graphene substrate. Systematic studies performed on pentagonal and heptagonal defects in graphene flakes show that Ni13 deposited on heptagonal defected graphene flake is a promising candidate with a large magnetic anisotropy energy of about ∼16 meV.