title: Highly Ordered Surface Self-Assembly of Fe₄ Single Molecule Magnets.
abstract: Single molecule magnets (SMMs) have attracted considerable attention due to low-temperature magnetic hysteresis and fascinating quantum effects. The investigation of these properties requires the possibility to deposit well-defined monolayers or spatially isolated molecules within a well-controlled adsorption geometry. Here we present a successful fabrication of self-organized arrays of Fe4 SMMs on hexagonal boron nitride (h-BN) on Rh(111) as template. Using a rational design of the ligand shell optimized for surface assembly and electrospray as a gentle deposition method, we demonstrate how to obtain ordered arrays of molecules forming perfect hexagonal superlattices of tunable size, from small islands to an almost perfect monolayer. High-resolution low temperature scanning tunneling microscopy (STM) reveals that the Fe4 molecule adsorbs on the substrate in a flat geometry, meaning that its magnetic easy axis is perpendicular to the surface. By scanning tunneling spectroscopy (STS) and density functional theory (DFT) calculations, we infer that the majority- and minority-spin components of the spin-split lowest unoccupied molecular orbital (LUMO) can be addressed separately on a submolecular level.
authors.affiliation: †Department of Physics and ‡Department of Chemistry, University of Konstanz, 78457 Konstanz, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Erler
authors.forename: Peter
authors.initials: P
authors.lastname: Schmitt
authors.affiliation: †Department of Physics and ‡Department of Chemistry, University of Konstanz, 78457 Konstanz, Germany.
authors.forename: Nicole
authors.initials: N
authors.lastname: Barth
authors.affiliation: †Department of Physics and ‡Department of Chemistry, University of Konstanz, 78457 Konstanz, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Irmler
authors.affiliation: †Department of Physics and ‡Department of Chemistry, University of Konstanz, 78457 Konstanz, Germany.
authors.forename: Samuel
authors.initials: S
authors.lastname: Bouvron
authors.forename: Thomas
authors.initials: T
authors.lastname: Huhn
authors.forename: Ulrich
authors.initials: U
authors.lastname: Groth
authors.affiliation: †Department of Physics and ‡Department of Chemistry, University of Konstanz, 78457 Konstanz, Germany.
authors.forename: Fabian
authors.initials: F
authors.lastname: Pauly
authors.affiliation: †Department of Physics and ‡Department of Chemistry, University of Konstanz, 78457 Konstanz, Germany.
authors.forename: Luca
authors.initials: L
authors.lastname: Gragnaniello
authors.affiliation: †Department of Physics and ‡Department of Chemistry, University of Konstanz, 78457 Konstanz, Germany.
authors.forename: Mikhail
authors.initials: M
authors.lastname: Fonin
keywords: Single-molecule magnet; density functional theory; electrospray deposition; hexagonal boron nitride; scanning tunneling microscopy; scanning tunneling spectroscopy