Graphene for next generation magnetic devices: A first-principles study

Graphene, an atomic thin sheet of monolayer carbon atoms, is deemed to replace silicon and revolutionize the electronics industry. It has massless Dirac fermions and exhibits ballistic charge transport, a prerequisite for upcoming futuristic nanodevices, such as field-effect transistors, sensors, etc. However, it lacks an intrinsic electronic bandgap and thus is obsolete for use in these applications. In this work, a first principles study is used to predict the opening of a bandgap in graphene by an engineered introduction of modulations in its lattice. Moreover, it is found that the atomic modulation and the addition of hydrogen atoms at sub-lattices induce magnetism in the graphene sheets. The hydrogen-induced itinerant magnetism (ferromagnetic or antiferromagnetic) depends on the type of defects and the structure of the sheet. This hydrogen-induced spin promotes the role of graphene as a potential material for magnetic memory device applications. Furthermore, with the creation of atomic vacancies and quasilocalized states, it is deemed to allow selective permeation (water/gas) and thus paves the way for its use in-filtration (membrane technology) and hydrogen storage applications.