CuI growth on copper surfaces under molecular iodine action: influence of the surface anisotropy in the iodine monolayer

Halide nucleation and growth on monocrystalline copper substrates under molecular halogens action was studied by means of Auger Electron Spectroscopy (AES) and Scanning Tunnelling Microscopy (STM). It was found that copper iodide grows on Cu(1 0 0) and Cu(1 1 1) in a layer-by-layer mode with its outer hexagonal plane parallel to the substrate surface. The STM images of copper iodide demonstrate Moiré-like superstructures. The nature of these superstructures is explained in terms of superposition of the copper iodide layer and the underlying “interface” monolayer. It was found that the interface layer preserves geometrical and electronic structure of the saturated chemisorbed iodine monolayer for both copper planes.