SILVER NUCLEATION DURING THE ELECTROLYSIS OF PASSIVATING SILVER-NITRATE MELTS POTENTIOSTATIC CONDITIONS

The nucleation of a single silver crystal on a platinum microcathode w as studied potentiostatically during the electrolysis of passivating s ilver nitrate melts. The histograms of the times of appearance of the first nucleus exhibit a maximum. The fraction of nuclei forming prior to the maximum is 0. 3-0.4, both in passivating and nonpassivating mel ts. The maximum indicates that the nucleation process is a transient p rocess even in passivating melts. The nucleation constants in the Volm er equation are much larger for passivating than for nonpassivating me lts, which is to be explained by the passivating agent influencing, no t only the material being deposited (silver) but also the state of the platinum substrate.