Spin transport of dibenzotetraaza[14]annulene complexes with first row transition metals

Based on spin-polarized first-principles density functional theory in conjunction with the nonequilibrium Green's function method, the spin transport properties of transition metal (TM)-dibenzotetraaza[14]annulene (DBTAA) complexes (TM = Ti, V, Cr, Mn, Fe, Co, Ni, and Cu) sandwiched between two Au electrodes are investigated. The results show that Fe- and Co-DBTAA can display perfect spin filtering behavior in a wide bias voltage region. Moreover, it is found that the connected position of anchoring groups on the complexes affect significantly the spin filtering efficiency. The observed spin filtering behavior is explained by the spin-resolved transmission spectrum and molecular projected self-consistent Hamiltonian state analyses.