Switching On Magnetism in Ni-doped Graphene

TL;DR

This study investigates how Ni doping induces magnetism in graphene, revealing that curvature and strain can switch Ni impurities from non-magnetic to magnetic states, which is crucial for spintronic applications.

Contribution

It uncovers the curvature-dependent magnetic behavior of substitutional Ni impurities in graphene and predicts strain-induced magnetic switching.

Findings

Ni impurities are non-magnetic in flat graphene.

Ni impurities develop magnetic moments in metallic nanotubes.

Strain can induce magnetic transitions in Ni-doped graphene.

Abstract

Magnetic properties of graphenic carbon nanostructures, relevant for future spintronic applications, depend crucially on doping and on the presence of defects. In this paper we study the magnetism of the recently detected substitutional Ni (Ni(sub)) impurities. Ni(sub) defects are non-magnetic in flat graphene and develop a non-zero magnetic moment only in metallic nanotubes. This surprising behavior stems from the peculiar curvature dependence of the electronic structure of Ni(sub). A similar magnetic/non-magnetic transition of Ni(sub) can be expected by applying anisotropic strain to a flat graphene layer.