Chronopotentiometry-driven electrodeposition of Cu–Ni–W thin films on indium tin oxide substrates: a comprehensive study of microstructure and corrosion behaviour

Cu–Ni–W thin films were deposited by varying the current density from –5 to –60 mA cm^–2 using the galvanostatic chronopotentiogram method on indium tin oxide (ITO) coated glass substrates. X-ray diffraction analysis revealed that Cu–Ni–W thin films exhibited face-centered cubic structures with the presence of specific crystallographic planes, particularly (111), (200) and (220) at 2θ values of 43.4°, 50.7° and 74.7°, respectively. The additional peaks observed at other 2θ values correspond to the NiW and Ni₄W phases. The scanning electron microscopy micrographs of the films demonstrated a uniform structure characterized by a compact and dense morphology. The surface of the films displayed a metallic lustre attributed to the presence of Cu, Ni and W. The cross-sectional micrographs of the films indicated an average thickness of 1.1 to 1.2 µm. The energy dispersive X-ray spectroscopy analysis have shown that an increase in deposition current density leads to a rise in the relative concentration of Ni and W within the films, whereas the concentration of Cu decreased. The XPS survey spectrum also confirmed the presence of metallic Cu, Ni and W in the deposits. It was found that film deposited at higher current densities favours the growth of a smaller crystalline size of 17 nm and a higher degree of texture coefficient of 2.48. The maximum micro-strain of approximately 16% was calculated from the peak broadening of the X-ray diffractograms. The strong (111) texture and nano-crystallites as confirmed by XRD, resulted in an outstanding corrosion resistance of 16.22 kΩ-cm² for the film deposited at –60 mA cm^–2.