Tuning Molecule-Mediated Spin Coupling in Bottom-Up Fabricated Vanadium-TCNE Nanostructures

TL;DR

This study demonstrates how molecule-mediated interactions can tune spin coupling in engineered V-TCNE nanostructures, revealing controllable magnetic behaviors at the atomic scale.

Contribution

It introduces a method to manipulate spin interactions in hybrid nanostructures using atomic-scale fabrication and spectroscopy, with insights supported by theoretical calculations.

Findings

Kondo behavior can be quenched in V-TCNE complexes despite unchanged spin-polarized orbitals

Variable ferromagnetic coupling between V atoms is mediated by a single TCNE molecule

Density functional calculations support the experimental observations

Abstract

We have fabricated hybrid magnetic complexes from V atoms and tetracyanoethylene (TCNE) ligands via atomic manipulation with a cryogenic scanning tunneling microscope. Using tunneling spectroscopy we observe spin-polarized molecular orbitals as well as Kondo behavior. For complexes having two V atoms, the Kondo behavior can be quenched for different molecular arrangements, even as the spin-polarized orbitals remain unchanged. This is explained by variable spin-spin (i.e., V-V) ferromagnetic coupling through a single TCNE molecule, as supported by density functional calculations.