Fabrication of stable nanopatterns on metals

Nanopatterns on metal surfaces can be easily created by ion sputtering. However, due to the fast diffusion processes characterizing these materials, the nanostructures are often unstable at room temperature and above. This effect prevents the use of such patterned substrates in nanotechnology applications. In this letter, we present a simple oxidation process able to stabilize these features durably. The method has been tested on Cu, but its generality suggests that it can be applied to many other metals.