10.1007/s11124-008-1002-1

Abstract

Based on the model taking into account the appearance of a morphological instability and the evolution of a surface with time during the selective anodic dissolution of a homogeneous A-B alloy with the predominant content of the electrochemically negative metal A, equations for the critical potential E cr and overpotential η cr of the surface development are derived. Criteria of the nature of chemical hindrances of the selective dissolution in the over-critical range are formulated. The E cr and η cr values corresponding to the breakage of the morphological stability of the A-B alloy surface (with the atomic silver part X Ag = 0.65 to 0.95) in an acidic nitrate solution containing diverse amounts of silver ions ( 10 -4 to 10 -2 M) are experimentally found. The character of the effect of the atomic gold content in the alloy and the concentration of silver ions in the solution on η cr and E cr values of the alloys is determined. The nature of the kinetic limitations of the selective dissolution in the over-critical potential range is clarified. PACS numbers: 82.45.Q