Nanostructuring and wettability of ion treated Au thin films

Abstract

The formation of Au nanostructures (NSs) under 8 keV Ne+ ion treatment of Au thin film is investigated to explore the involved mechanism using experimental and theoretical approaches. This study is based on atomic force microscopy, Rutherford backscattering spectrometry, and contact angle measurements. The results are discussed in the light of the thermal spike model and tridyn simulation. It is observed in the simulations that Ne ion treatment results in ejection of atoms from the surface due to elastic collision induced transfer of energy and increase in lattice temperature due to the formation of thermal spikes. The effect of ion dose on the surface morphology is also explored using a two-dimensional detrended fluctuation analysis (DFA).The DFA gives information about the fractal dimension (Df) and Hurst exponent (H) of the surface. The fractal dimension (Df) shows that irregularity of a surface is significantly influenced by ion treatment. The contact angle of the water droplet with the surface is discussed with the interface width and fractal dimension. The competition among nuclear sputtering, de-wetting, and diffusion processes results in the formation of NSs. It also demonstrates that the experimental findings are in good agreement with the theoretical results.