| Popis: |
The small-signal impedance of chemical cells with “blocking” electrodes is dominated at low frequencies ( f Hz ) by the impedance of the metal-electrolyte interfaces, which is accurately represented by Z rmi = A (j ω ) − n . The frequency exponent n , n n to the fractal dimension d of the rough interface. However, we have found no correlation between n and d from experiments using aqueous electrolytes and metal and semiconductor electrodes. A new model for the transient response of a rough electrode-electrolyte interface to a constant voltage pulse is proposed. Computer simulations, similar to the diffusion limited aggregation model, using measured profiles as fixed (non-growing) clusters, gave exponent n in good agreement with experiments. |
