Nanopatterning of copper (111) vicinal surfaces by oxygen-induced mesoscopic faceting

We report the preparation of periodic nanostripes on vicinal copper surfaces. For the investigated $Cu(n,n,n−1)$ surfaces $[n=4,3,2],$ an oxygen-induced mesoscopic faceting of the regular monoatomic stepped surfaces into periodic nanostripes consisting of Cu(111) and $Cu(110)–O(2×1)$ facets is observed. The width and thermal stability of these nanostripes increase with the terrace length of the initial vicinal surfaces. Stripe widths of 50, 20, and 12 nm were obtained for Cu(443), Cu(332), and Cu(221), respectively. Whereas on Cu(221) the nanostripes disappear above 450 K, they are stable up to 800 K on Cu(443). For the latter surface, the nanostructures are found to be unusually stable and could be observed ex situ by atomic force microscopy under ambient conditions.