Bias-Controlled Giant Magnetoresistance through Cyclopentadienyl–Iron Multidecker Molecules

Abstract

We investigated giant magnetoresistance (GMR) across cyclopentadienyl−iron multidecker molecules [Fe m (C 5 H 5 ) n ] using the density functional theory and nonequilibrium Green's function techniques. An oscillation behavior of the molecular magnetic moments was observed. Spin-polarized transport calculations through the lead-multidecker molecule-lead junctions predicted large biascontrolled magnetoresistive response, with the highest GMR ratio up to 2.0 × 10 4 %. The positive to negative conversion of the GMR values was also observed with bias change. The transmission spectra and eigenvalues of the molecular junctions were calculated to understand the mechanism of spin transport in these systems. Various ways to manipulate the GMR behavior are illustrated, opening up prospects of new molecular spintronic devices.

Computational insights into the concomitant changes of hollow interior evolution in [SbnAunSbn]m (n=3, 4, 5, 6; m= -3, -2, -1, -2) complex

“…41 This structure feature a short Au-Sb bond distance of 2.643 Å. It is marginally longer than the Au-Sb bonds found in stibine-gold complexes such as Au(SbMes 3 ) 2 [ClO 4 ](2.58 Å) 42 and it is almost identical to that in [Au(SbPh 3 )] 4 + ClO 4 (2.656 Å -2.658 Å). 43 44 The Sb-Sb bond distance (average 2.805 Å), spanning a narrow scope with 0.016 Å, range from 2.801 Å to 2.817 Å, which is in reasonable agreement with the available experimental data (2.812 Å -2.819 Å) in the known cyclo-Sb 5 species 45(a) and slightly shorter than the known calculation data, 2.929 Å in cyclo-Sb 5 .…”

“…1 Ferrocene and analogous organometallic species called metallocenes have seen abundant application as building blocks for new materials, 2(a) catalysts, 2 (b) nanodevices 2(c) and polymers. 2(d) For example, V n (Bz) n+1 is proposed to serve as a building block material for high-density information storage and quantum computing; 3 the [Fe m (C 5 H 5 ) n ] can be sued as a new molecular spintronic devices; 4 and [(C 5 H 5 )Ti(C 8 H 8 )] n is an excellent candidate for future molecule-based spintronic applications. 5 Sandwich compounds are not only confined within carbon-containing ligands.…”

Magnetic and Quantum Transport Properties of Small-Sized Transition-Metal-Pentalene Sandwich Cluster

“…In a previous study, however, the GMR was realized by changing the magnetization directions of two magnetic electrodes, but the spin state of the sandwich remained unchanged in the whole transport process. 28 Since TM 2n Pn n+1 has different spin states, our study shows that the GMR effect can be acquired by different mechanisms. The SFE and GMR at finite bias voltage V b were further investigated.…”

“…25 Finite sandwiches such as V 3 Bz 4 and Fe 3 Cp 4 may possess spinfilter capability, if the sandwich is placed between two proper electrodes. 12,27 Outstanding giant magnetoresistance (GMR) was observed in different types of Fe m Cp n , 28 while the spinvalve GMR effect was found in Sc 3 Bz 4 in our recent study. 21 It would be interesting to note that polycyclic-hydrocarbon ligands may also make sandwich clusters, and the ligands can hold more TM atoms in the sandwich regions.…”

“…Although the GMR effect was also found in FeCp 2 , the corresponding value at zero bias is only 992%. 28 In addition, the transport properties of the molecular junctions at zero bias voltage were also investigated at a higher theoretical level. We optimized the molecular junctions using the DFT-D method 64 and then calculated the GMR and SFE values using Meta-GGA (TB09LDA) functional.…”