Site selective Cu deposition on Au microcrystallites: corners, edges versus planar surfaces

Abstract

Among epitaxially grown metal over metal systems, Cu on a Au surface forms a notable exception given the large lattice mismatch (similar to 11.2%). Although widely observed, Cu growth on Au is less understood at both nano and bulk length scales. In this work, we have relied on Au microcrystallites which provide adequate platform to access both the length scales and thus have examined Cu electroless deposition using electron microscopy techniques, on planar as well as corner and edge regions distinctly. Amazingly, the growth at different regions was found to be highly varied; the corners were found to be most active, followed by edges and planar regions. Interestingly, the sharper the corner, the higher the Cu deposition is. Importantly, both Au{111} and Au{100} facets could be explored simultaneously, using a routine electron microscope.