STRUCTURAL AND ELECTRONIC PROPERTIES OF REDUCIBLE OXIDE THIN FILMS AND NANOSTRUCTURES
WG2 members: Jan Ingo Flege, Jan Höcker, Marc Sauerbrey, Julian Cambeis, Jens Falta
Reducible oxides intrinsically offer a wide range of structural, electronic, and chemical properties. In many circumstances, these materials properties may exhibit spatial variations even down to the nanometer scale, which poses a formidable challenge for the intentional growth of extended homogeneous oxide phases and nanostructures as well as their subsequent characterization, e.g., during surface chemical reactions. At the University of Bremen, we address these issues by employing low-energy electron microscopy (LEEM), a full-field imaging technique that allows monitoring of dynamic surface processes with nanometer resolution at video rates.
The figure shows the growth of nanoscale CeO2(111) on a Ru(0001) substrate during evaporation of metallic Ce in molecular oxygen ambient. After initial nucleation at the step edge, the islands grow in size. Interestingly, permanent domain boundaries are formed between CeO2(111) domains of different registry to the substrate while islands of identical azimuthal lattice orientation are seen to coalesce upon further growth.