Stability, Electronic and Magnetic Properties of In-Plane Defects in Graphene: A First-Principles Study

The electronic and magnetic properties of graphene can be modified through combined transition-metal and nitrogen decoration of vacancies. In this study, we used density functional theory to investigate the following defect motifs: nitrogen doping, nitrogen decoration of single and double vacancies (SVs and DVs), TM doping (TM = Co, Fe), TM adsorption on nitrogen-doped graphene, and combined TM–nitrogen chemistries in SV and DV (TM–Nx) configurations. The results show that the highest magnetic moments are supported in TM–Nx defect motifs. Among these defects, Co–N3, Fe–N3, and Fe–N4 defects are predicted to show ferromagnetic spin structures with high magnetic moments and magnetic stabilization energies, as well as enhanced stability as expressed by favorable formation energies, and high TM binding energies.