Spin transport through graphene/molecules-based magnetic tunnel junctions*

Spin transport through organic molecules is motivated by the ability to tune at the atomic scale the spin injection/detection properties. This property is barely achievable in inorganic systems and it is due to the possibility of designing molecules atoms by atoms. With this respsct, ferromagnetic metal/molecules interfaces has focused most of the attention.
A common issue remains the quality of such complex interfaces. Ferromagnetic metals like Co, Fe, Ni are transition metals and are easily oxidizable. The presence of oxygen atoms is known to completely modify the magnetic and electronic properties of magnetic surfaces.The recently proposed Ni/graphene electrodes for spintronics applications is very appealing due to their protected character. Moreover, graphene is more and more viewed as a good platform for the absorption of molecules.
In this talk, I will describe the fabrication process of magnetic tunnel junctions made of Ni/graphene/nitrobenzene molecules/Co/Au. I will especially detail the electrografting procedure to attach molecules over the grahene surface. I will then present the magnetotransport measurements performed at low temperatures. I will also discuss the bias voltage dependence of the magnetoresistance.