Reversible faceting of the copper (110) surface: X-ray Fresnel reflectivity

Abstract

We have investigated the thermodynamic stability of copper surfaces with small misalignments from the [110] direction using x-ray Fresnel reflectivity. We find that the misaligned orientation is stable only at high temperatures. At low temperatures the surface breaks up into a hill-and-valley structure of predominantly (110) facets. This process is reversible. Exposure of the surface to ${\mathrm{O}}_2$ increases the stability of the (110) facets, counter to simple theoretical ideas.