Atomically smooth CeO2(001) films on YSZ(001)

CeO2 is a non-inert support material for heterogeneous catalysis applications. Here, we present a facile growth procedure for the preparation of CeO2(0 0 1) thin films supported by YSZ(0 0 1) suitable for combined catalytic and structural investigations. Detailed structural and chemical analysis of the films was conducted directly after UHV preparation and after a tube furnace annealing step giving rise to significant restructuring of the film. Complete characterization using AFM, cross-section HR-STEM, GIXRD, XPS, and polarization-resolved IRRAS showed that the film is fully oxidized and atomically flat with a coherent crystal lattice over the full film thickness. A dislocation network at the interface compensates the lattice mismatch between film and the YSZ support, yielding a film with bulk in plane lattice parameters and small tensile out of plane strain. The surface of the CeO2 film is bulk terminated, and stabilized by the presence of hydroxyl groups for polarity compensation.