Modulation of the spin transport properties of the iron-phthalocyanine molecular junction by carbon chains with different connection sites
Graphical abstract
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%.
Introduction
In recent years, the single-molecule device has been an interesting topic due to the progress in experimental techniques for manipulating individual molecules [1], [2], [3] and the availability of first-principles method to describe the electrical properties of devices [4], [5], [6]. Many novel and promising physical properties have been demonstrated in various kinds of molecular systems, including rectifying [7], [8], switching [9], [10], negative differential resistance (NDR) [11], [12], field effect transistors [13], [14], and spin filtering [15], [16]. Of particular interests among the large number of single-molecule devices are the molecule spintronic device due to its importance in next-generation electronics systems, and the search for suitable spintronic materials is a basic but crucial task. The metal phthalocyanines (MPcs) and its derivatives display a surprising variety of functions due to their tunable electronic and magnetic properties by changing the central transition metal atom. The spin transport properties of MPcs (M = Mn, Fe, Co, Ni, Cu, and Zn) sandwiched between two single-walled carbon nanotubes were investigated, but only MnPc and FePc can act as nearly perfect spin filters [17].
The symmetry-matched interaction between CuPc and the electrodes is important to enhance the electron transmission [18], Liu et al. found that the adsorbed small molecules show diverse effects which depend on the connecting position between the metalloporphyrin and the electrodes [19]. Generally, the single-molecule magnet as stated above was set to be connected to gold electrodes with sulfur atoms [20], [21], also connected to carbon nanotube (ACNT) electrodes or graphene nanoribbons (GNR) electrodes by carbon atoms [22], [23]. In addition, carbon atomic chains have been achieved recently via chemical methods [24] and studied widely [25], [26], [27], [28], and the magnetic and electronic properties of the carbon chain complex system with GNRs can be tuned by the shape of graphene edges (armchair or zigzag) [25] and hybrid structures [26]. Zeng et al. proposed that carbon chain bridging GNR electrodes can be as a good spin-filter, but the bias region for such spin-filtering is less than 0.2 V [27]. On the other hand, the connection between chain and electrode such as paralinkage and meta-linkage in benzene also can lead to different conductance and spin effect [28].
In this paper, we examine the spin transport properties of FePc molecule sandwiched between two gold electrodes through carbon chain by employing the non-equilibrium Green's function method combined with the density functional theory, and three kinds of connect position between FePc molecule and carbon chain are considered. Our calculated results clearly reveal that the efficiency and the bias region of spin filtering are affected significantly by the connecting position between the FePc and carbon chain.
Section snippets
Model and method
The molecular device we study is illustrated schematically in Fig. 1, where the FePc molecule is bridged between two Au (111) electrodes through the carbon chain consisting of nine carbon atoms. Three models, M1 ∼ M3, are considered depending on the connecting position between the FePc and the carbon chain. For M1, the left and right carbon chains are symmetrically connected to the two carbon atoms of the left and right benzenes of FePc, respectively, but connected to its one carbon atom of the
Results and discussion
Fig. 2 demonstrates the magnetism for M1∼M3 with the isosurface of spin density (∇ρ = ρup − ρdown) at zero bias. The cyan and magenta colors stand for the up-spin and down-spin components, respectively. One can see that all the Fe atoms for three models are strong spin-polarized, which shows an antiparallel feature as compared with the adjacent nitrogen (carbon) atoms. In other word, the magnetism of FePc molecule mainly origins from Fe atom and carbon atoms of the carbon chain which are strong
Conclusions
Using the non-equilibrium Green's function method combined with the density functional theory, we have calculated the spin transport properties of an iron-phthalocyanine (FePc) molecule connected to two Au electrodes by carbon chains. Our calculated results clearly reveal that the efficiency and the bias region of spin filtering for such a device is affected significantly by the connecting position between the FePc and carbon chains. These findings indicate that the carbon-chain-modified FePc
Acknowledgments
This work was supported by the National Natural Science Foundation of China (Grant Nos. 61371065, 51302022), the Hunan Provincial Natural Science Foundation of China (Grant No 2015JJ3002, 2015JJ2009, 2015JJ2013), the Scientific Research Fund of Hunan Provincial Education Department (Grant No. 14A013).
References (34)
- et al.
Org. Electron.
(2011) - et al.
Carbon
(2014) - et al.
Phys. Lett. A
(2015) - et al.
Science
(1999) - et al.
Nature
(2002) - et al.
J. Am. Chem. Soc.
(1997) - et al.
Phys. Rev. Lett.
(2012) - et al.
Sci. Rep.
(2014) - et al.
Appl. Phys. Lett.
(2012) - et al.
Nano Lett.
(2004)
Appl. Phys. Lett.
Nature
J. Chem. Phys.
Appl. Phys. Lett.
Nano Lett.
J. Mater. Chem. C
J. Chem. Phys.
Phys. Chem. Chem. Phys.
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