The influence of citrate and tartrate on the electrodeposition and surface morphology of Cu-Ni layers

This study examined the influence of citrate and tartrate as complexing agents on the electrodeposition and surface morphology of Cu-Ni layers. The alloys obtained in the tartaric acid and sulphate baths were nobler than those obtained in the citric acid/citrate and citric acid/citrate/tartaric acid media. The results indicated that the complexing medium influences the nobility and the type of mass transport of the alloy formed. The morphology of the electrodeposited Cu-Ni layers changed from a rather porous appearance in the absence of the complexing agents to nodular, cracked mud and cauliflower appearances for the citric acid/sodium citrate/sodium sulphate medium, tartaric acid/sodium sulphate medium and citric acid/sodium citrate/tartaric acid/sodium sulphate medium, respectively. The chemical composition of the Cu-Ni layers revealed the preferential deposition of copper. The ultraviolet-visible spectrophotometry measurements indicated the occurrence of the d-d type transition, regardless of the complexing medium employed.