Tuning the magneto-optical response of TbPc2 single molecule magnets by the choice of the substrate

In this work, we investigated the magneto-optical response of thin films of TbPc2 on substrates which are relevant for (spin) organic field effect transistors (SiO2) or vertical spin valves (Co) in order to explore the possibility of implementing TbPc2 in magneto-electronic devices, the functionality of which includes optical reading. The optical and magneto-optical properties of TbPc2 thin films prepared by organic molecular beam deposition (OMBD) on silicon substrates covered with native oxide were investigated by variable angle spectroscopic ellipsometry (VASE) and magneto-optical Kerr effect (MOKE) spectroscopy at room temperature. The magneto-optical activity of the TbPc2 films can be significantly enhanced by one to two orders of magnitude upon changing the molecular orientation (from nearly standing molecules on SiO2/Si substrates to nearly lying molecules on perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) templated SiO2/Si substrates) or by using metallic ferromagnetic substrates (Co)

Self-Assembled Two-Dimensional Molecular Host-Guest Architectures from Trimesic Acid

The adsorption of 1,3,5-Benzenetricarboxylic (Trimesic) Acid (TMA) to a single crystal graphite surface has been studied under Ultra High Vacuum conditions. This work focuses on inducing a particular self-assembly structure by OMBE (Organic Molecular Beam Epitaxy), characterized by periodic non-dense-packing of the molecules. Two coexisting phases could be imaged with sub-molecular resolution by STM. Induced by directed hydrogen bonding, the organic molecules built in both cases a two-dimensional grid architecture with molecular caves. This two-dimensional host structure can accept single trimesic acid guest molecules in different positions

Room-Temperature Scanning Tunneling Microscopy Manipulation of Single C60 Molecules at the Liquid-Solid Interface: Playing Nanosoccer

This scanning tunneling microscopy (STM) study uses a supramolecular two-dimensional architecture of trimesic acid molecules adsorbed on a graphite substrate as a host for the incorporation of C60 as a molecular guest. By choosing a proper solvent, it was possible to verify that self-assembly of the host-guest structure can be accomplished at the liquid solid interface. Because of the ideal steric match with the molecular bearing of the host structure, C60 buckminster fullerenes are feasible guests. It was possible to coadsorb C60 within cavities of the open TMA structure from the liquid phase, and lateral manipulation of the molecular guest by the STM tip was demonstrated at room temperature. Because of the increased tip-sample interaction as a result of lower tunneling resistance, a transfer of a C60 molecule from one cavity of the host structure to an adjacent one was achieved