Ts

Fig. 5. COM vs. t plots for silver electrodissolution. (a) Constant current density 30 (xA. cm"2, (b) Constant current density 4 pA cm'2 at 298 K.

On the other hand, the fact that the experimental value of ยก3 is higher than j3 = 0.200.25 as expected for a simple surface diffusion model [8], may reflect again either the influence of the electric field on surface diffusion processes for metal atoms at the electrochemical interface [20] or the existence of energetic barriers at step edges [16] enhancing the growth of instabilities normal to the electrode surface. Presumably, the presence of additional contributions to the energy barriers at step edges could account

Fig. 6. 85x85 nm2 in-situ STM images obtained during the electrodissolution of silver in 1 M HC104. Constant current density 30 nA cm"2 at 298 K.

for the dependence of on the potential applied to the working electrode, as in the case of roughness relaxation of column-structured gold electrodes in acids [24].

Fig. 6. 85x85 nm2 in-situ STM images obtained during the electrodissolution of silver in 1 M HC104. Constant current density 30 nA cm"2 at 298 K.

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