Electrolytic Migration of Ag-Pd Alloy Wires with Various Pd Contents

Abstract

During Ag ion migration in an aqueous water drop covering a pair of parallel Ag-Pd wires under current stressing, hydrogen bubbles form first from the cathode, followed by the appearance of pure Ag dendrites on the cathodic wire. In this study, Ag dendrites with a diameter of 0.2–0.4 μm grew toward the anodic wire. The growth rate (v) of these dendrites decreased with the Pd content (c) with a linear relationship of: $$ v = 10.02 - 0.43 \, c $$ . Accompanying the growth of pure Ag dendrites was the formation of a continuous layer of crystallographic Ag2O particles on the surface of the anodic wire. The deposition of such insulating Ag2O products did not prevent the contact of Ag dendrites with the anodic Ag-Pd wire or the short circuit of the wire couple.