Vanadium oxide nanostructures: from zero- to three-dimensional

Oxide structures with nanometric dimensions exhibit novel physical and chemical properties, with respect to bulk oxide materials, due to the spatial confinement and the proximity of the substrate. They derive their atomic structure and morphology, on the one hand, from the interactions at the interface between the oxide overlayer and the substrate and, on the other hand, from kinetic constraints during the growth process. Here we describe the formation of vanadium oxide nanostructures on a single-crystal metal surface and their characterization by scanning tunnelling microscopy (STM) and ab initio density functional theory (DFT) calculations. We show that vanadium oxide nanostructures can be formed on Rh(111) with morphologies ranging from quasi-zero- to three-dimensional and that the oxide growth can be tuned into a particular dimensionality by careful adjustment of experimental parameters. These 'artificial oxide phases' display new physical and chemical properties, which make them potentially interesting materials for nanotechnology applications.