Preferential Nucleation of Metallic Clusters on a Nanotemplate: Co on Oxygen-Faceted Re(12(3)over-bar1)

Preferential nucleation of cobalt nanoclusters at specific sites on oxidized faceted Re(12 (3) over bar1) is investigated by means of Auger electron spectroscopy (AES), low energy electron diffraction (LEED), and scanning tunneling microscopy (STM). An oxygen terminated nanofaceted Re surface containing ridges and valleys is used as the nanotemplate in this study. Deposition of cobalt onto this surface, followed by annealing to similar to 800 K, results in preferential cobalt nanocluster nucleation and growth within the valleys of the nanofaceted surface. Decreasing the nanofacet width, cobalt coverage, and annealing temperature lead to the same preferential cobalt nanocluster self assembly, an increase in nanocluster density, and a decrease in nanocluster volume. The preferential nucleation and growth observed for Co nanoclusters on faceted Re makes this a model system for future studies of different substrates and metallic overlayers more relevant to catalytic reactions.