Ion Beam Sputtering (IBS) is known to produce surface nanopatterns over macroscopic areas on a wide range of materials. However, in spite of the technological potential of this route to nanostructuring, the physical process by which these surfaces self-organize remains poorly under- stood. We have performed detailed experiments of IBS on Si substrates that validate dynamical and morphological predictions from a hydrodynamic description of the phenomenon. Our results elucidate flow of a nanoscopically thin and highly viscous surface layer, driven by the stress created by the ion-beam, as a description of the system. This type of slow relaxation is akin to flow of macroscopic solids like glaciers or lead pipes, that is driven by defect dynamics.
@article{arxiv.1203.1167,
title = {Solid flow drives surface nanopatterning by ion-beam irradiation},
author = {M. Castro and R. Gago and L. Vázquez and J. Muñoz-García and R. Cuerno},
journal= {arXiv preprint arXiv:1203.1167},
year = {2015}
}