Real-space investigation of polarons in hematite FeO.

In polarizable materials, electronic charge carriers interact with the surrounding ions, leading to quasiparticle behavior. The resulting polarons play a central role in many materials properties including electrical transport, interaction with light, surface reactivity, and magnetoresistance, and polarons are typically investigated indirectly through these macroscopic characteristics. Here, noncontact atomic force microscopy (nc-AFM) is used to directly image polarons in FeO at the single quasiparticle limit.

Effect of Different InO(111) Surface Terminations on CO Adsorption.

InO-based catalysts have shown high activity and selectivity for CO hydrogenation to methanol; however, the origin of the high performance of InO is still unclear. To elucidate the initial steps of CO hydrogenation over InO, we have combined X-ray photoelectron spectroscopy and density functional theory calculations to study the adsorption of CO on the InO(111) crystalline surface with different terminations, namely, the stoichiometric, reduced, and hydroxylated surface. The combined approach confirms that the reduction of the surface results in the formation of In adatoms and that water dissociates on the surface at room temperature.

Actinide Coordination Chemistry on Surfaces: Synthesis, Manipulation, and Properties of Thorium Bis(porphyrinato) Complexes.

Actinide-based metal-organic complexes and coordination architectures encompass intriguing properties and functionalities but are still largely unexplored on surfaces. We introduce the in situ synthesis of actinide tetrapyrrole complexes under ultrahigh-vacuum conditions, on both a metallic support and a 2D material. Specifically, exposure of a tetraphenylporphyrin (TPP) multilayer to an elemental beam of thorium followed by a temperature-programmed reaction and desorption of surplus molecules yields bis(porphyrinato)thorium (Th(TPP)) assemblies on Ag(111) and hexagonal boron nitride/Cu(111).