Long-range and strong ferromagnetic graphene by compensated n-p codoping and π-π stacking

Generating magnetism in graphene and preserving its extraordinary properties are essential to the development of graphene-based spintronics. By using first-principles calculation methods, we propose a new scheme based on compensated n-p codoping and non-covalent pi-pi stacking with F4-TCNQ, to engineer some hybrid structures of Fe/graphene/F4-TCNQ. Our results firstly show that F4-TCNQ adsorption on graphene can preserve the original electronic properties of graphene by minimizing the distortion of carbon-carbon lattices due to non-covalent pi-pi interaction between graphene and F4-TCNQ. Moreover, F4-TCNQ adsorption on graphene can lead it to p-type, which is in agreement with experimental finding. Then, n-type Fe adatom on F4-TCNQ/graphene system forms very stable hybrid Fe/graphene/F4-TCNQ system due to compensated n-p codoping interaction. Further calculations reveal that a long-range and strong ferromagnetic coupling of two Fe adatoms is realized by F4-TCNQ exchange interaction in the hybrid Fe/graphene/F4-TCNQ system. This study provides a new method to realize ferromagnetic graphene and preserve its extraordinary properties, which will open a promising way to tailor the electronic properties and magnetic properties of graphene so as to be suited for future application in nanoelectronics and spintronic devices. (C) 2015 Elsevier Ltd. All rights reserved.