Effect of Superparamagnetic Fe3O4 Nanoparticles on Schottky Barriers of Graphene

We demonstrated the effect of superparamagnetic Fe3O4 nanoparticles on Schottky barriers of graphene, in which the Fe3O4 nanoparticles were fabricated by a hydrothermal method and the single-layer graphene sheets were mechanically exfoliated from Kish graphite. The Fe3O4 nanoparticles were superparamagnetic with the saturation magnetic moment of about 32 emu/g at room temperature. We have found that the Fe3O4 nanoparticles decorated on the graphene surface can dramatically modify the Schottky barriers of the whole devices possibly due to the magnetic stray field from the Fe3O4 nanoparticles in proximity to the graphene. The Schottky barrier could be further tuned by the quantity of Fe3O4 nanoparticles.