First-principles study of the magnetic properties of Ti-coated graphene sheets and carbon nanotubes

Abstract

We perform first-principles pseudopotential calculations to investigate the magnetic properties of Ti-coated graphene sheets and carbon nanotubes. We examine the dependence of the magnetic property on pseudopotential and exchange-correlation functional. We find the magnetic properties are similar, although the magnetic moments and stability of ferromagnetic solutions depend on pseudopotential and exchange-correlation functional. For one monolayer coverage of Ti, both graphene sheet and carbon nanotube are found to be ferromagnetic, with the magnetic moments of 1.62 and $1.46 \mu_{\vcy}$ per Ti atom, respectively. On the graphene sheet, however, the magnetic moment decreases very rapidly with increasing of the Ti coverage. Based on the analysis of the localized states near the Fermi level, we discuss the origin of ferromagnetic solution in Ti films and nanowires.