Tunnel magnetoresistance of a C n BN (n = 58 and 68) molecular junction

Abstract

This research considers a system consisting of C n BN (n = 58 and 68) attached by single and multiple atoms to two ferromagnetic electrodes with finite cross sections. The effects of the contacts, the position of the doped atom, the cage type and the gate and bias voltages on the coherent spin-dependent transport was studied by applying the non-equilibrium Green's function technique. The results show that pure spin currents are obtained. Also, the tunnel magnetoresistance (TMR) can reach as high as about 60% with appropriate selection of the bias and gate voltages, the type and position of the doped atoms and the cage type. A negative TMR is observed with a change of gate voltage when B and N atoms are substituted in C60 and C70 molecules.