▎ 摘　　要

The magnetoresistance (MR) of Fe3O4-graphene-Fe3O4 junctions has been experimentally studied at different temperatures. It is found that a barrier exists at the Fe3O4/graphene interface. The existence of the interfacial barrier was further confirmed by the nonlinear I-V characteristics and nonmetallic temperature dependence of the interfacial resistance. Moreover, spin dependent transport at the interfaces contributes -1.6% MR to the whole device at room temperature and can be regulated by an external electric field. (C) 2011 American Institute of Physics. [doi:10.1063/1.3552679]