Structural characterization, optical response, and corrosion resistance of bismuth coatings

We present the results obtained from the deposition of nanostructure bismuth coatings through DC pulsed unbalanced magnetron sputtering. The Bi coatings were deposited simultaneously on common glass, silicon, and Ti6AL4V substrates in order to evaluate the optical properties, morphology, and microstructure as a function of the pulsed frequency deposition, and to establish the relationship between these properties and corrosion resistance. The microstructure was evaluated via X-ray diffraction (XRD), and the morphology of the coatings was evaluated through scanning electron microscopy (SEM) and atomic force microscopy (AFM). Optical properties were characterized through absorbance and transmittance spectra. The XRD analysis indicated that the coatings are polycrystalline. The SEM micrographs showed that the coatings are grown as droplets form. AFM revealed roughness values from 20.0 to 28.8 nm. Finally, from the optical measurements, it was possible to establish the band-gap energy of the Bi coatings.