Composition control of multicomponent electrodeposited alloy films is very challenging. For example, non-linearity between the deposit composition and bath constitution could occur in alloy electrodeposition systems containing Fe and Ni, due to the anomalous codeposition phenomena (which usually means electrodeposition kinetics is controlled by the reduction of intermediates at the surface of cathode rather than the mass-transfer in the diffusion layer). On the other hand, it is still uncertain if the composition of alloy electrodeposition system is chaotic within the experimental errors in the electrolyte preparation and electrodeposition cell setup.

In this presentation, we will introduce some recent explorations in the composition control of the quaternary alloy Cu-Co-Fe-Ni. The initial stage composition will be investigated with cross-section SEM-EDS line-scans, whereas the nonlinearity will be explored with electrodeposition at a fixed duration but different applied potentials, concentrations of depositing species, and supporting electrolytes with different pH buffer capability.