Appropriate deposition parameters for formation of fcc Co–Ni alloy nanowires during electrochemical deposition process

The effect of deposition potential on the crystal structure and composition of Co–Ni alloy nanowires is studied by XRD, FE-SEM and EDX. The alloy nanowires deposited at −3.2 V are metastable fcc phase Co–Ni. The alloy nanowires deposited at −1.8 V are hcp phase Co–Ni. The formation of the metastable fcc alloy nanowires can be attributed to smaller critical clusters formed at the high potential as the smaller critical clusters favor fcc structure because of the significant surface energy effect. The content of Co inside nanowires increases with increasing potential. This can be understood by the polarization curves of depositing Co and Ni nanowires, which show that the current density ratio of Ni to Co at low potential has larger value than that at high potential.