Evolution of surface roughness parameters and microstructure in two-phase nanocrystalline Co–Cu films electrodeposited onto ITO coated glass substrates at different deposition potentials

Abstract

In the present research, we have studied the effect of deposition potential on the film composition, structural, and morphological properties of the electrodeposited Co–Cu thin films grown onto indium tin oxide coated glass substrates. For this purpose, the properties of the films were analyzed by means of X-ray diffraction, energy dispersive X-ray spectroscopy (EDX), and atomic force microscopy (AFM) characterization techniques. Structural characterizations showed that all of the Co–Cu films consist of hexagonal close-packed (hcp) Co and face-centered cubic (fcc) Cu phases. The hcp Co (002)/fcc Cu (111) peak intensity ratio was found to increase as the deposition potential decreased towards more negative values. An increase in the Co content in the Co–Cu films was observed as the applied deposition potential was made more negative according to EDX analysis. The decrease of the applied deposition potential towards more negative values also induced a decrease in the average crystallite sizes of both Co and Cu particles. AFM study indicated that a granular structure of the electrodeposited Co–Cu films regardless of deposition potential. As the applied deposition potential was made more negative, the surface roughness and particle size decreased considerably. Besides, two additional roughness parameters, surface kurtosis and the surface skewness were also obtained and discussed by means of the obtained results under the study.