Preparation and annealing-induced structural transition of self-organized nanostripes on the electropolished aluminium surface

Self-organized nanostripe patterns with a wavelength of 100 nm and an amplitude of 4 - 5 nm were formed on the surface of high-purity aluminium by electropolishing. The thermal stability of the nanostripe patterns was investigated experimentally by using a needle-sensor atomic force microscope in an ultra-high vacuum after annealing the sample in a high vacuum. We found that the originally highly ordered nanostripe structures transformed into many domains separated by various boundaries, and different nanostripe patterns formed, the belt-like boundaries especially formed "cross" patterns on the surface. We also found that the vacuum annealing had the tendency to efface the nanostripe structures.