Phase identification in electrodeposited Ag-In alloys by ALSV technique

During electrodeposition of Ag-In alloy coatings phenomena of self-organization and formation of spatio-temporal structures can be observed. The difficulties in the determination of the local phase composition in the observed structures are mostly connected with the strong heterogeneity of the coatings consisting of several alloy phases. The results obtained with electrochemical techniques, such as anodic linear sweep voltammtery (ALSV) are compared with results obtained by X-ray analysis and SEM. In the proposed electrolyte for dissolution of Ag-In alloy coatings (12 M LiCl + 0.1 M HCl) the dissolution peaks of the pure metals, Ag and In, have a potential difference of about 650 mV. The peaks, corresponding to the alloy phases, are situated between the dissolution potentials of Ag and In, their height depending on the deposition current density, i.e. on the percentage content of the alloy. Each ALSV peak is ascribed to a separate phase as a result of very good agreement between the alloy characterization by ALSV technique and by X-ray technique. This opens the possibility for ASLV identification of the phase composition in the different regions of the microscopically observed structures.