Sharif Digital Repository

Nickel nanostructure thin films were electrodeposited on copper plates to investigate the fractal study. Scharifker's equations were derived for instantaneous and progressive nucleation and 3D growth of hemispherical centres under diffusion-controlled condition to calculate in situ change of fractal dimension of surface. It was assumed that the layer could be formed completely when fractal dimension of surface inclined to 2. Moreover, the fractal analysis of atomic force microscopy (AFM) images has confirmed the presumed model. Also, the power values of power spectral density (PSD) of the AFM images were determined using fast Fourier transform (FFT) algorithms. The PSD plots are approximated... 

The electrodeposition of nickel was studied using electrochemical techniques in different electrolytes and various agents. The voltammetry analysis clearly showed that the electrodeposition of nickel was a diffusion-controlled process associated with a typical nucleation process. The current transients represented instantaneous nucleation with a typical three-dimensional (3D) growth mechanism. Scharifker's equations were derived for instantaneous and progressive nucleation of the 3D growth of the spherical centers under diffusion-controlled condition. The number of nucleation sites increased with the increment in overpotential and Ni 2+ concentration. Atomic force microscopy was used to... 

A 3D continuum code coupled with a kinetic Monte Carlo module has been developed for the simulation of Ni electrocrystallization in the initial stages of nucleation and growth. Mass transfer in solution was controlled by a finite-difference code which is distributed over an irregular nanoscale grid system in vertical direction to the substrate. Deposition events such as surface diffusion, chemisorption and crystallization in the system were considered in a KMC module that processes the output of a diffusion-controlled scheme in probability functions to model electrodeposition process on surface. Electrochemical data of this simulation was simultaneously generated according to analytical...