Effects of pH Value of the Electrolyte and Glycine Additive on Formation and Properties of Electrodeposited Zn-Fe Coatings
Environmentally friendly and cyanide-free sulfate bath under continuous current and the corrosion behavior of electrodeposits of zinc-iron alloys were studied by means of electrochemical tests in a solution of 3.5% NaCl in presence and absence of glycine. The effects of pH on the quality of Zn-Fe coatings were investigated in order to improve uniformity and corrosion protection performance of the coating films. The deposit morphology was analyzed using scanning electron microscopy (SEM), and X-ray diffraction (XRD) was used to determine the preferred crystallographic orientations of the deposits. It was found that the uniformity and corrosion resistance of Zn-Fe coating films were strongly associated with pH of the coating electrolyte. To obtain the effect of pH on the film quality and corrosion performances of the films, the corrosion test was performed with potentiodynamic anodic polarization method. It was also observed that uniformity and corrosion resistivity of the coating films were decreased towards pH = 5 and then improved with increasing pH value of the electrolyte. The presence of glycine in the plating bath decreases the corrosion resistance of Zn-Fe coatings.
On the role of surface active agents in the nucleation step of metal electrodeposition on a foreign substrate
Abstract The effect of surface active agents on the thermodynamics and kinetics of electrochemical nucleation has been analysed on the basis of the classical and atomistic theories of phase formation. The theoretical predictions were compared with experimental results obtained by studying the nucleation kinetics of mercury on platinum in both the absence and the presence of potassium nitrate, which proved to be a surface active agent with respect to the bulk mercury phase. The overpotential dependence of the stationary nucleation rate was measured at different potassium nitrate concentrations. It was shown that surface active agents which change the properties of the new bulk phase may not significantly affect the state of small clusters during the process of nucleus formation.
Investigating the Optical properties of cd1-xznxs thin films deposited by the Dip Technique
A Thesis submitted to the Department of Physics, Kwame Nkrumah University of Science and Technology, in partial fulfillment of the requirement for the degree of 
Master of Science (Solid State Physics)