Potential Distribution Of Graphene/3d Magnetic Planar Junction :first-principles Study

Graphene has great potential in the field of nanoelectronics due to its excellent electronic properties. In this paper, We have studied the electronic properties of a metal/graphene/metal(Nickel and Cobalt) sandwich-like magnetic plane junction and the modulating effects of the magnetic properties of the Co and Ni electrode on the contact barrier of the junction are systematically investigated using first-principles method, the main works are as follows:(1) We have studied the electronic properties of Co/graphene/Co sandwich-like magnetic planar junction and the modulating effects of the magnetic properties of the Co electrode on the contact barrier of the junction using first-principles method. Dependence of the contact barrier of the junction on thickness of the electrodes, stacking configuration between electrode and graphene, and magnetic orders of the Co electrodes are obtained.We find that, in both C-s and M-s staking configurations, the charge transfer between graphene and Co electrodes tends to saturation with the increase of the thickness of the Co electrodes no matter the electrode is ferromagnetic(FM) state or antiferromagnetic(AFM) state, which are helpful to understand the stabilizations of the magnetic moments and the contact barrier of the interface. Interestingly, we find that the magnetic order between the two electrodes can effectively control the stacking configuration between the electrode and graphene.(2) We have studied the electronic properties of a Ni/graphene/Ni sandwich-like magnetic tunneling junction. Dependence of the contact barrier of the junction on thickness of the electrodes, stacking configuration between electrode and graphene, and magnetic orders of the Ni electrodes are obtained. We find that, no matter the electrode is FM state or AFM state, the most stability structure of Ni/graphene/Ni is C-s staking configurations, which are constent to the analysis of the system energy and the charge transfer between graphene and Ni electrodes and the contact barrier of the interface.(3) We have studied the electronic properties of a Ni/graphene/Co sandwich-like magnetic planar junction. Dependence of the contact barrier of the junction on thickness of the electrodes, stacking configuration between electrode and graphene, and magnetic orders of the Ni/Co electrodes are obtained. We find that, in both C-s and M-s staking configurations, the charge transfer between graphene and Ni electrodes more than the charge transfer between graphene and Co electrodes and tends to saturation with the increase of the layer of the Ni/Co electrodes no matter the electrode is FM state or AFMstate, which are helpful to understand the difference of contact barrier of the interface between graphene and Ni electrode and Co electrode.