Kinetics of the initial stage of electrolytic deposition of metals: II. Potentiostatic conditions

Abstract

The kinetics of the initial stage of electrolytic deposition of a thin metal film onto an inert cathode are considered with the assumptions that nucleation is completed and the overvoltage is kept constant with time. The process is studied separately in the cases of pure ohmic control, volume diffusion control and phase boundary transition control of the growth of the crystallites. Expressions are derived for the radius of a single crystallite, the mean crystallite radius and the strength of the electric current through the electrolytic cell as functions of time and overvoltage for each of the above types of growth control. The analysis shows that taking the Gibbs-Thomson effect of crystallite curvature into account leads to (i) the appearance of an intercept in the asymptotic linear dependences of the current and the crystallite radius on the square root of time for ohmic and volume diffusion control, and (ii) violation of the linear dependences on time of the square root of the current and of the crystallite radius for phase boundary transition control.