One-Dimensional Iron−Cyclopentadienyl Sandwich Molecular Wire with Half Metallic, Negative Differential Resistance and High-Spin Filter Efficiency Properties

Abstract

We present a theoretical study on a series of novel organometallic sandwich molecular wires (SMWs), which are constructed with alternating iron atoms and cyclopentadienyl (Cp) rings, using DFT and nonequilibrium Green's function techniques. It is found that that the SMWs are stable, flexible structures having half-metallic (HM) properties with 100% negative spin polarization near the Fermi level in the ground state. Some SMWs of finite size show a nearly perfect spin filter effect (SFE) when coupled between ferromagnetic electrodes. Moreover, their I-V curves exhibit negative differential resistance (NDR), which is essential for certain electronic applications. The SMWs are the first linear molecules with HM, high SFE, and NDR and can be easily synthesized. In addition, we also analyze the underlying mechanisms via the transmission spectra and spin-dependent calculations. These findings strongly suggest that the SMWs are promising materials for application in molecular electronics.

Mixed‐Metal Lanthanide–Iron Triple‐Decker Complexes with a cyclo‐P5 Building Block

“…[11] Although some heavier Group 15-lanthanide compounds, such as phosphides (Ln À PR 2 ), [12] arsenides (Ln À AsR 2 ), [12d, 13] stibides (Ln À Sb 3 ), [14] and bismutides (LnÀBiÀBiÀLn) [15] are known, the first molecular polyphosphide of the rare-earth elements, [(Cp* 2 Sm) 4 P 8 ] (Cp* = h 5 -C 5 Me 5 ), was recently synthesized. [16] The structure of the complex is very rare and can be described as a realgartype P 8 4À ligand trapped in a cage of four samarocenes.…”

“…[3] It was calculated that these compounds have half-metallic properties with 100 % negative spin polarization near the Fermi level in the ground state. [4] In contrast to this investigation in the gas phase, studies on related organometallic triple-and multidecker sandwich complexes containing f-block elements (lanthanides or actinides) in condensed phase remain rare; [5] studies were mostly on the cyclooctatetraene ligand and its derivatives. The only rare-earth-element triple-decker complex with heterocycles is the low-valent scandium 1,3,5-triphosphabenzene complex [{(h 5 -P 3 C 2 tBu 2 )Sc} 2 (m-h 6 :h 6 -P 3 C 3 tBu 3 )], which was obtained by cocondensation of scandium vaporized in an electron beam with an excess of the phosphaalkyne tBuCP.…”

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

“…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.…”

Length and end group dependence of the electronic transport properties in carbon atomic molecular wires

“…28 Generally speaking, the transmission coefficient can be related to the molecular orbitals which have been modified by the electrodes. These modified molecular orbitals can be obtained from the molecular projected self-consistent Hamiltonian ͑MPSH͒, 29,30 where the self-consistent of molecular junction is projected onto the molecule, and this MPSH matrix is diagonalized. The mapping of the infinite open twoprobe system into a finite system using the Green's function formalism is accomplished via evaluation of the following matrix: central scattering region, and the right region ͑including several gold layers from the right electrode͒ shown in Fig.…”