AFM Spectral Analysis of Self–Agglomerated Metallic Nanoparticles on Silica Thin Films

Stochastic parameters of self–agglomerated metallic nanoparticles on a dielectric film surface were studied using atomic force microscopy (AFM) analysis. In this regard, the rough surfaces including the nanoparticles were analyzed and characterized using structure function, roughness exponent and power spectrum density of the AFM profiles and their gradients, for different metal concentrations and heat treatment temperatures. The diffusion parameters, such as activation energy, of the nanoparticles initially accumulated on the surface into a porous and aqueous silica thin film were obtained using the AFM spectral analysis of the profiles and their gradients. It was found that the tip convolution effect can dramatically change the diffusion parameters obtained using the surface roughness analysis of the normal profiles. However, use of the surface roughness analysis of gradient of the profiles resulted in a nearly independent tip convolution effect procedure to study the kinetics of the nanoparticles into the silica film. Based on the obtained results, a brief discussion on the mechanism of diffusion process was also proposed. Keywords: Silver nanoparticles, silica thin film, AFM, diffusion, tip convolution