Spin preservation of a Ni adatom on amorphous graphene

Two-dimensional amorphous materials can be regarded as electronic systems with a combination of amorphous and dimensional confinement effects that contributes to the discrete localized tail states near the Fermi level. In general, the magnetic properties of magnetic atoms may not be preserved upon doping into nonmagnetic metals or adsorbing onto their surfaces, e.g., Ni atoms adsorbed onto nonmagnetic metal or semiconductor surfaces. Earlier experimental and theoretical studies showed that as a Ni atom adsorbed on pristine graphene, the magnetic moment completely disappeared. Here, using first -principles calculations, we investigate the structural and magnetic properties of Ni single atom and dimer adsorbed on amorphous graphene (AG). We find that the carbon eight -member ring in AG gives rise to the most stable adsorption site for Ni adatoms and that the spin moments of adsorbed Ni single atom and dimer can be partially preserved. The mechanism of this spin preservation of Ni adatoms can be understood in terms of the disorder -induced localization and its tight -binding model. Such a localization effect due to the disordered lattice of AG weakens the hybridization between the Ni d- and graphene pi orbitals, thereby leading to a preservation of spin moment in Ni adatoms. Our findings offer promise for many applications such as single -atom catalysis and spintronic devices.