First-principles study on the structures and electronic properties of graphene-supported Nin (n=1-6) clusters

The structural and electronic properties, such as adsorption energy, magnetic property, and charge-transferring process of Ni-n (n = 1-6) clusters interacting with pristine, strained and defective graphene were investigated by using the density functional theory calculations with the Perdew-Burke-Ernzerhof exchange-correlation energy functional. By introducing strain and defects, the stability of the cluster-graphene system was improved significantly. The magnetic moments increased monotonically for Ni-n clusters on pristine and strained graphene while exhibited an oscillating behaviour for defective graphene. On the other hand, more charges being transferred from Ni-n clusters to defective graphene were observed compared with pristine and strained graphene.