Cyclopentadienyl-Benzene Based Sandwich Molecular Wires Showing Efficient Spin Filtering, Negative Differential Resistance, and Pressure Induced Electronic Transitions

TL;DR

This study uses density functional theory to explore transition metal sandwich molecular wires, revealing their potential as stable, highly spin-polarized conductors with unique electronic properties like spin filtering, NDR, and pressure-induced phase transitions.

Contribution

It introduces novel TM-cyclopentadienyl-benzene sandwich wires exhibiting high stability, ferromagnetism, and advanced spintronic functionalities not previously reported.

Findings

All SMWs are highly stable ferromagnetic half-metals.

Finite clusters exhibit spin filter properties with Au electrodes.

Some systems show negative differential resistance (NDR).

Abstract

Using density functional theory, we investigate TM-cyclopentadienyl-benzene sandwich molecular wires (SMWs) which are composites of TM-cyclopentadienyl and TM-benzene wires (TM = transition metal (V, Fe)). All the SMWs are found to be highly stable ferromagnetic half-metals, showing spin switching behavior. Transport calculations show that finite size clusters display spin filter property when coupled with Au electrodes on either side. I-V characteristics of all systems confirm the spin filter property, with Au-BzVCpVBz-Au displaying exceptionally high performance. In addition to spin filtering, the Au-BzFeCpFeBz-Au system also shows negative differential resistance (NDR). Compression causes an abrupt reduction in magnetic moment and a transition to a metallic phase, while stretching causes an increase in magnetic moment. Half-metallicity is preserved for modest amounts of stretching and compression.