Nucleation and Growth of a Binary Electrodeposited Ni-Co Thin Film

Document Type : Original Article


Bio-Geosciences and Materials Engineering Laboratory, Higher Normal School, Hassan II University of Casablanca, Casablanca, Morocco


The microscopic arrangement of alloys has a significant influence on their electrical, thermal, mechanical, and catalytic properties. In this respect, we have developed nickel-cobalt alloy films by electrodeposition on an ITO glass substrate while examining nucleation and growth processes during the first steps of electrocrystallization. Energy Dispersive X-ray Spectroscopy (EDX) approved stoichiometry (1,1) of the alloy elaborated. X-ray diffraction (XRD) showed that the Co-Ni binary electrodeposited at different potentials crystallizes in a cubic structure that belongs to the Pm3̅m space group. From chronoamperometry and cyclic voltammetry curves, we concluded that the Co-Ni/ITO system is quasi-reversible, with diffusion of Ni2+ and Co2+ cations being the controlling step.  The ascending part of the current-time transients investigation has shown that the Ni-Co electrodeposition mechanism is characterized by instantaneous nucleation in line with 3D growth.  This result is confirmed by comparison of the experimental chronoamperometry data with the theoretical models of Scharifker and Hills on the one hand, and Bewick, Fleischmann, and Thirsk on the other.


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