INVESTIGATION OF CHARGE-TRANSPORT ACROSS THE AG AGI-INTERFACE - (II) - DILATOMETRIC STUDY OF THE ANODIC-DISSOLUTION OF SILVER/

The anodic dissolution of silver at the solid-solid interface Agl alph a-AgI has been studied by means of a high precision (capacitive) dilat ometer. The dilatometer signal corresponds to the change of the anode thickness during the dissolution experiment. Under galvanostatic condi tions and in a definite pressure range the dilatometer signal oscillat es periodically, i.e., the length change of the anode with time is not a simple and linear function of the current density. The mean length change is, as expected, proportional to the electric current. The osci llation modes of the dilatometer signal are correlated with simultaneo us electrochemical oscillations at the anode and give evidence for the influence of morphological effects on the interface kinetics. From th e combination of both electrochemical and dilatometric (mechanical) ex periments, we draw conclusions on a possible mechanism of the observed oscillatory kinetics.