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In this paper the results of an examination of the surface roughness and morphology dependence of silver thin films up to 100 nm thick deposited on a microscope glass on the deposition rate and on the deposition time are presented. It was found that, for a constant deposition rate, the surface roughness exhibits minimum at a certain layer thickness. This coincides with the turning point when the influence of the substrate surface on the deposition process becomes negligible, i.e., to the change in the nature of the system substrate/deposit from Ag/glass to Ag/Ag. For a constant layer thickness, sthe surface roughness minimum, achieved at a certain deposition rate, coincides to the turning point when the average free path for vertical adatom mobility becomes zero.

The role of defects on a substrate surface during the initial stages of nucleation and growth ofAg deposited electrochemically and physically on highly oriented pyrolytic graphite (HOPG) has been observed ex situ by scanning tunneling microscopy (STM). The silver was electrodeposited under current controlled electrochemical conditions at 26μA/cm2, which corresponded to a deposition rate of 0.1 monolayers (ML) per second. For comparison, physical deposition of Ag on HOPG was performed by DC Ar + ion sputtering, at the same deposition rate and for the same deposition times. In both cases, Ag grows in an island growth mode, but the distribution of the islands appears to be quite different. In physical deposition, the Ag islands are almost homogeneously distributed over the substrate surface and a slight accumulation of islands on steps does not contribut e significantly to the overallmorphology. This indicates the crucial role of point defects on the substrate in the initial stages of nucleation. In electrochemical deposition, more line d defects are observed after a flow of current, andtheir role in the beginning of the nucleat ion is more pronounced. Lined defects are responsible for the string-like shaped domains of deposited atoms. Also, the existence of string-like shaped nucleation exclusion zones is indicated. The problem of the formation of nucleation exclusion zones,which appear only in electrochemical deposition, has been reconsidered and a new explanaton of their formation is given. A mathematical model for the calculation of the radius of the nucleati on exclusion zone has been developed.

By combining the techniques of electrochemical slow potentiodynamic, AC impedance and atomic force microscopy (AFM), it was shown that the differences in the anodic dissolution rates of Al in 0.5 NaCl solutions as measured experimentally in the potential region between the corrosion and pitting potential, are mainly due to differences in surface roughness of the electrodes used. It was shown that mechanical grinding and polishing of the electrode surface with emery paper (400 grit) and alumina polishing powder (Ø 0.25 μm) can produce surfaces differing by a factor of 6 in the roughness factor Ra. By using AFM estimates of the roughness factors a true electrode capacitance of 4.63μC cm-2 and thickness dox ≈ 2.0 nm for the barrier layer of the surface film was estamited. The outer part of the film is porous, partly as amorphous Al(OH)3, or crystalline bayerite (Al2O3∙3H2O).