Temperature Influence on the Morphology and Roughness of Silver Deposit Formed by Cementation

Abstract The morphology and surface roughness of silver deposits formed by cementation in 0.5 M H 2 SO 4 solution containing 0.5 M CuSO 4 was investigated at various temperatures. The influence of O 2 on the morphology of deposited Ag on the Cu surface was studied in solutions containing 20 or 100 mg/dm 3 initial Ag + . Surface‐height‐distribution diagrams were calculated from scanning‐electron‐microscopic (SEM) images. For the lower Ag + concentration, the formation of granular deposits occurred in the presence of O 2 . In contrast, under anaerobic conditions, rather flat deposits with tiny Ag crystals were observed. For the higher Ag + concentration, the presence of O 2 did not significantly affect the morphology of the Ag deposit, but increasing temperature resulted in more‐compact and denser dendrites. Differences in the Ag‐deposit morphology and surface roughness were attributed to a different mechanism in the absence of O 2 . Under anaerobic conditions, a competitive reaction between Ag + and Cu + occurs in bulk solution, which consumes additional Ag + ions. The SEM images and, especially, distribution diagrams of the surface height provided useful information on the formation and expansion of anodic sites on the Cu surface at various temperatures.