Modulation of the spin transport properties of the iron-phthalocyanine molecular junction by carbon chains with different connection sites

• The hybridization between FePc molecule and carbon chain.
• The spin filtering effect can be obtained.
• The different bias region of spin filtering.
• The efficiency is affected significantly by the connecting position.

Based on the non-equilibrium Green's function method combined with the density functional theory, the spin transport properties of an iron-phthalocyanine (FePc) molecule connected to two Au electrodes by carbon chains are investigated, and three kinds of connecting position between FePc molecule and carbon chains are considered. It is found that the spin filtering effect and the negative differential resistance (NDR) behavior in these systems can be achieved in the calculated bias region. However, the efficiency and the bias region of spin filtering are affected significantly by the connecting positions. The above results are explained by the spin-resolved transmission spectrum, electron transmitting path, molecular projected self consistent Hamiltonian state, and the local density of states (LDOS) analyses. Our calculations demonstrate a promising modification for developing molecule spintronic devices.

It is notable that the spin-filter efficiency is very large when the bias is less than 0.7 V, then decrease significantly to zero at 1.0 V for M1. M2 shows the unstable SFE between 17% and 85% in the whole bias range. However, M3 exhibits a perfect spin-filtering effect in the largest bias range and the smallest spin filter efficiency is found to be 90%.Figure optionsDownload as PowerPoint slide