High spin-filter efficiency and Seebeck effect through spin-crossover iron–benzene complex

Abstract

Electronic structures and coherent quantum transport properties are explored for spin-crossover molecule iron-benzene Fe(Bz)2 using density functional theory combined with non-equilibrium Green's function. High- and low-spin states are investigated for two different lead-molecule junctions. It is found that the asymmetrical T-shaped contact junction in the high-spin state behaves as an efficient spin filter while it has a smaller conductivity than that in the low-spin state. Large spin Seebeck effect is also observed in asymmetrical T-shaped junction. Spin-polarized properties are absent in the symmetrical H-shaped junction. These findings strongly suggest that both the electronic and contact configurations play significant roles in molecular devices and metal-benzene complexes are promising materials for spintronics and thermo-spintronics.

Computational demonstration of isomer- and spin-state-dependent charge transport in molecular junctions composed of charge-neutral iron(ii) spin-crossover complexes

“…This displacement could take the aforementioned molecular states into energy regions where the electrodes DOS drastically drops, decreasing the coupling with the electrodes and, thus, reducing the transmission. Also, both complexes exhibit a high SFE, in line with the values obtained for other iron(II)-based single-molecule junctions, 22,23,60,73 in contrast to devices based on different transition metal-Co(II), Cr(II)-complexes that display much lower SFE values. 74,75 Finally, we report the results obtained for the ligands L1 and L2, and their respective complexes in the LS configuration.…”

Spin-Crossover and Coherent Transport Behaviors of a Six-Coordinate Iron(II) Complex with a N4O2 Donor Set

“…Recently, by combination of the electron and spin degrees of freedom at the single-molecule level, molecular spintronics has attracted much research attention since it is promising for the next generation of nanoelectronic devices in high-density information storage and quantum computing. , On the basis of magnetic molecules, various functional molecular devices, such as spin-filter, , molecular switch, rectification, and molecular memory, , as well as negative differential resistance effect, , have been prepared or demonstrated. Among the existing magnetic molecular systems, spin-crossover (SCO) complexes are one of the most popular and are possible building blocks due to their magnetic bistability between the HS and LS states. − In general, SCO compounds can be switched between the LS and HS states upon the application of external stimuli, such as temperature, light, field, and pressure. , One of the remaining challenges limiting the long-term development of molecular spintronics is to find appropriate single-molecule magnets used to design functional molecular devices.…”

Spin crossover and high spin filtering behavior in Co-Pyridine and Co-Pyrimidine molecules

“…By calculating the absorption energies, we conclude that the SCO cobalt complex prefers to be absorbed on the top sites of Gold (1 1 1) surface. The Au-S bond length is fixed to be 2.187 Å [7].…”

“…Large numbers of transition mental (TM) complexes, which include the transition metal and organic ligand such as benzene, pyrene and anthracene, have been studied over the last few years [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][29][30][31]. Most investigations of TM complexes are focused on their electronic, magnetic and optical properties for their potential applications on the spintronic materials [14][15][16][29][30][31].…”

“…So far, a large number of experimental and theoretical investigations are focusing on the Fe(II) or Fe(III) SCO complex [1][2][3][4][5][6][7][8][9][10], and researches on cobalt-based SCO complex are rare. Moreover, transport investigations of SCO complexes at the single molecular level are scarcely reported.…”