Magnetism of Substitutional Co Impurities in Graphene: Realization of Single $\pi$-Vacancies

TL;DR

This paper uses ab initio calculations to explore the magnetic properties of cobalt substitutional impurities in graphene, revealing complex magnetism that can be modeled by simple theoretical frameworks, and suggests experimental fabrication methods.

Contribution

It demonstrates that Co substitutional impurities induce spin-polarization in graphene and can be effectively modeled by $\pi$-vacancy and Heisenberg models, linking theory and potential nanostructure engineering.

Findings

Co impurities induce spin-polarization in graphene.

Magnetism can be mapped to $\pi$-vacancy and Heisenberg models.

Potential fabrication methods include electron irradiation and ion bombardment.

Abstract

We report {\it ab initio} calculations of the structural, electronic and magnetic properties of a graphene monolayer substitutionally doped with Co (Co$_{sub}$) atoms. We focus in Co because among traditional ferromagnetic elements (Fe, Co and Ni), only Co$_{sub}$ atoms induce spin-polarization in graphene. Our results show the complex magnetism of Co substitutional impurites in graphene, which is mapped into simple models such as the $\pi$-vacancy and Heisenberg model. The links established in our work can be used to bring into contact the engineering of nanostructures with the results of $\pi$-models in defective graphene. In principle, the structures considered here can be fabricated using electron irradiation or Ar$^+$ ion bombardment to create defects and depositing Co at the same time.