1 research outputs found
Ultrasmooth Ru(0001) Films as Templates for Ceria Nanoarchitectures
Single crystalline magnetron sputter-deposited
Ru(0001) epitaxial thin films on c-plane sapphire were prepared and
used as a template for reactive CeO<sub>2</sub> growth. Low-energy
electron microscopy and diffraction, as well as transmission electron
microscopy and atomic force microscopy, experiments were performed
to investigate the crystallinity and morphology of the prepared films.
Multiple cycles of Ar<sup>+</sup> sputtering and high-temperature
annealing produces films of exceptional surface quality. High-temperature
reactive ceria growth leads to perfectly aligned triangular single-crystalline
CeO<sub>2</sub>(111) islands of extraordinary morphological and structural
homogeneity. At the chosen growth conditions, ceria nucleation takes
place only at V-shaped surface defects on the otherwise atomically
flat Ru terraces, opening up the possibility to influence the nucleation
by introducing artificial surface defects using standard etching techniques.
Due to their high crystallinity and extraordinary surface quality,
these substrates present a low-cost alternative to Ru single crystals
for model studies in heterogeneous catalysis and also allow for the
use of destructive investigation techniques and irreversible surface
modifications