Fabrication and characterisation of electrodeposited and magnertron-sputtered thin films

The MnO–Zn thin films were fabricated by radio frequency (RF) magnetron sputtering and compared with pulse electrodeposition (PED) Zn thin films, doped with MnO and ZrO nanoparticles. Surface morphology, structural properties, chemical composition and corrosion resistance of these coatings were investigated by using scanning electron microscopy, X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy, 3-D scanning interferometry and environmental chamber. Surface morphology and degree of crystallinity have different behaviours for different deposition methods. Pulse-coated films have polycrystalline structure with high surface roughness (Ra), whereas sputtered films are monocrystalline with reduced roughness (Ra). Corrosion tests of both RF sputter and PED films revealed that the distribution of corrosion products formed on the surface of sputter films were not severe in extent as in case of electrodeposited coatings. Results showed that the doping of ZrO nano-sized particles in Zn matrix and Mn–Zn composite films significantly improved the corrosion resistance of PED thin films. Keywords: Corrosion resistance, electro-deposition, magnetron sputtering, surface analysis, thin films.