Investigating Molecular Systems Based on Rare-Earth Metals via SX-STM

Rare-earth metals exhibit promising optical, magnetic, and catalytic properties and are used in a wide variety of energy conversion applications and emerging quantum technologies. Recently, molecular systems such as coordination complexes and supramolecular networks have attracted attention due to their potential to precisely control the location and local environment of the rare-earth atoms by incorporating them into a molecular scaffold. These molecular approaches provide an engineering control in which the metal ion, bond length, angle and functionality of the organic linker can be varied depending on the application.<br/>In this contribution, we present a synchrotron x-ray scanning tunneling microscopy (SX-STM) approach to investigate molecular systems based on various rare-earth atoms and organic linker moieties at the nanoscale. We use STM to study the inter- and intramolecular interactions of supported molecular systems at the nanoscale. Further, we use x-ray absorption near edge spectroscopy (XANES) via SX-STM to probe the local oxidation state and change in the total electron yield (TEY) depending on the rare-earth concentration. This work provides fundamental understanding of local chemical environment of rare-earth ions caged inside the molecular scaffolds and will be useful for designing novel rare-earth molecular systems for potential applications.