On-Surface Structural and Electronic Properties of Spontaneously Formed Tb$_2$Pc$_3$ Single Molecule Magnets
Abstract
The single molecule magnet (SMM) bis(phthalocyaninato)terbium (III) (TbPc) has attracted steady research attention as an exemplar system for realizing molecule-based spin electronics. In this paper, we report on the spontaneous formation of TbPc species from TbPc precursors via sublimation in ultrahigh vacuum (UHV) onto an Ag(111) surface. The molecules on the surface are inspected using combined scanning tunneling (STM) and non-contact atomic force microscopies (nc-AFM) at 5 Kelvin. Submolecular resolution and height dependent measurements supported by density functional theory (DFT) calculations unambiguously show the presence of both TbPc and TbPc species. The synthesis of TbPc species under UHV conditions is independently confirmed by chemical analysis. The high-resolution AFM imaging allows us to register the orientation of the topmost Pc ligand in both TbPc and TbPc relative to the underlying Ag(111) surface. Measurements of the electronic structure reveal the selective appearance of a Kondo signature with temperature 30K in the TbPc species, localized to the Pc ligand lobes. We attribute the presence of the Kondo resonance on select TbPc molecules to the orientation of internal molecular ligands. High-resolution AFM imaging identifies geometric distortions between TbPc molecules with and without the Kondo effect, the result of the complex interplay between structural and electronic differences.
Keywords
Cite
@article{arxiv.1805.03913,
title = {On-Surface Structural and Electronic Properties of Spontaneously Formed Tb$_2$Pc$_3$ Single Molecule Magnets},
author = {Jack Hellerstedt and Aleš Cahlík and Martin Švec and Bruno de la Torre and María Moro-Lagares and Barbora Papoušková and Giorgio Zoppellaro and Pingo Mutombo and Mario Ruben and Radek Zbořil and Pavel Jelinek},
journal= {arXiv preprint arXiv:1805.03913},
year = {2018}
}
Comments
29 pages, 8 figures; additional supplementary information in /anc directory