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.
@article{arxiv.0907.0490,
title = {Tuning Molecule-Mediated Spin Coupling in Bottom-Up Fabricated Vanadium-TCNE Nanostructures},
author = {Daniel Wegner and Ryan Yamachika and Xiaowei Zhang and Yayu Wang and Tunna Baruah and Mark R. Pederson and Bart M. Bartlett and Jeffrey R. Long and Michael F. Crommie},
journal= {arXiv preprint arXiv:0907.0490},
year = {2013}
}