Preparation and Annealing-Induced Structural Transition of Self-Organized Nanostripes on the Electropolished Aluminum Surface

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