The Effect of Copper and Silver Substrates on the Structure, Internal Stress, and Electrode Potential during the Initial Stages of Gold Electrodeposition

Abstract

The initial stage of epitaxial electrocrystallization of gold from an additive‐free, alkaline, sulfite solution on polycrystalline copper and silver substrates was found to be three‐dimensional crystallite formation. The crystallites on the copper substrates were laterally considerably smaller than those on silver. This effect is attributed to the larger lattice mismatch between gold and copper. On silver, substrate coverage occurred earlier and was followed by the formation of smaller, secondary crystallites. The internal stress in the gold deposits on silver was initially very small and tensile due to the small lattice mismatch and the large crystallite size. The stress rose to a maximum during secondary crystallite formation. On copper substrates, the stress was initially compressive because of the negative lattice‐mismatch component and then changed to tensile when crystallite coalescence became predominant.