Electronic structure and transport properties of early transition metal tripledeckers

Abstract

The electronic structure and transport properties of the Cp(2)BzM(2) (M = Sc, Ti, and V) tripledeckers are studied by spin polarized density functional theory and nonequilibrium Green's function method considering high-spin and low-spin states. Total energy calculations show that the sandwich structured Cp(2)BzSc(2) exists in a singlet state with no local magnetic moment on the Sc atoms. Cp(2)BzTi(2) in triplet state exists as a distorted tripledecker and is more stable than singlet and quintet states. Cp(2)BzV(2) stabilizes in the quintet state with a spin density of 2.4 on each vanadium atom. Hund's coupling plays a vital role in stabilizing the higher multiplets in case of titanium and vanadium clusters. In bigger clusters like Cp(3)Bz(2)M(4), Sc multidecker has one unpaired spin, Ti multidecker has five unpaired spins, and V multidecker has seven unpaired spins in total. Spin polarized electronic transport is found for all states of vanadium tripledecker and one state of the titanium tripledecker when connected to a gold two probe junction. Moderate to high-spin filter efficiencies are calculated for these states. Cp(2)BzSc(2) shows spin-independent electronic transport for all electronic states when introduced in the gold two probe junction. Current versus voltage curves are reported for selected clusters in the two probe setup.

Magnetothermoelectric Properties of Ferrocene-Based Compounds Sandwiched by Transition Metals in the Presence of Gold Electrodes

“…The increase of molecular size increases the spin multiplicity linearly which is very important to make a wire that transmits spin signals over large distances. 26 Hence, we increase the size of the molecules by repeating Fc and connected them through one of the transitional metal: V, Cr, Mn, Fe, Co, and Ni. The molecules are coupled to the Au(111) electrode through Co atoms (Figure 1).…”

“…Following the work of Ormaza et al, we extend the CoFc molecule to CoFcCo and study the thermoelectric and magnetothermoelectric properties of the molecule in the presence of the gold (Au(111)) electrodes, theoretically. The increase of molecular size increases the spin multiplicity linearly which is very important to make a wire that transmits spin signals over large distances . Hence, we increase the size of the molecules by repeating Fc and connected them through one of the transitional metal: V, Cr, Mn, Fe, Co, and Ni.…”

‘All-Metal’ Aromatic Sandwich Molecules: An Electronic Structure and Transport Study

“…Both the configurations have been previously studied for sandwich type double/multidecker molecules. [40][41][42][43][44] While it is understood that there may be many more coupling configurations in reality, but the cases studied here are two typical ones which capture the essence of molecule electrode bondings in sandwich systems. In the perpendicular case, two 4 × 4 electrodes of Ag(100)/Au(100) clusters are positioned ∼ 7.8 Å apart and Al 4 MAl 4 is inserted in between such that the Al Ag distances are all 2.8 to 3.00 Å and Al Au distances are 2.5-2.7 Å.…”

Transition‐Metal‐Based Multidecker Complexes as Hydrogen Storage Materials: A Theoretical Study

“…These complexes offer fast hydrogen adsorption and desorption, making them suitable candidates for usage. Amongst organometallic complexes multidecker complexes have been a topic of interest both for chemists and physicists and a lot of work has been performed on them both experimentally and theoretically . The first synthesized complex was ferrocene followed by other cyclopentadienyl complexes ,.…”