From Pure Oxides to Mixed Oxides: Model Systems for Structural and Catalytic Studies

As pure oxides and mixed oxide systems play an ever-increasing role in a variety of research fields ranging from catalysis over electrochemical applications to microelectronics, the present contribution aims at introducing a straightforward concept for the easy and reproducible preparation of well-defined and well-structured thin film model systems both for pure and mixed oxide systems. Exploiting the special structural and surface properties of vacuum-cleaved NaCl (001) growth templates, the concept is exemplified for the formation of nano-spheres (Ga2O3), nano-pyramids (In2O3), plates and needles (V2O5) and dendritic structures (Ga2O3-WO3). Careful tuning of the preparation conditions (substrate temperature, deposition rate, oxygen partial pressure or post-annealing temperature) allows the formation of special particle morphologies at much lower substrate temperatures (less than 400°C) than previously and usually applied.