Growth of Ag rows on Si(5 5 12)

Our scanning tunneling microscopy studies show that Ag deposited onto Si(5 5 12) and annealed to moderate temperatures (400–450 °C) forms well-ordered overlayer rows. These rows have aspect ratios up to 150:1 and therefore are possible candidates as “nanowires.” As the Ag coverage is increased, the rows grow in length and number until the surface forms a periodic array of such structures at ∼0.25 monolayer (ML). A statistical analysis of these rows reveals a linear increase in median row length as a function of coverage with a median length of 67 nm at full coverage (∼0.25 ML). At higher annealing temperatures (>500 °C), Ag continues to form row-like structures, but the rows are wider and cause local faceting of the underlying Si substrate. We can therefore conclude that the lower temperature Ag rows are actually a metastable arrangement of the surface.