Association Between Gold Grain Orientation and Its Periodic Steps Formed at the Gold/Substrate Interface

Nanoscale step structures have attracted recent interest owing to their importance in both fundamental and applied research, for example in adsorption, in catalysis, and in directing nanowire growth. Here, using a template stripping method to obtain vicinal-like surface structures on grains of polycrystalline gold, we investigated the effect of annealing temperature on the formation of these surfaces. Our experimental results revealed a clear correlation between the grain orientation angle (GOA) and the step periodicity along (112) crystallographic direction on the grain/substrate interface. The GOA was measured by using the electron backscatter diffraction with respect to the sample's normal direction. Using scanning tunneling microscopy to examine the same given grains, we found that their step periodicity decreases with increasing GOA. Formation of low-index terraces detaching from the substrate are considered as a kind of solid-solid dewetting. These results provide further understanding of the periodic step structure formation at the gold/substrate interface in a given grain.