Bismuth coatings deposited by the pulsed dc sputtering technique

Abstract

In this work we present the results obtained from the deposition of nano-structured bismuth coatings through DC pulsed unbalanced magnetron sputtering. The coatings were grown on two substrates: silicon and AISI steel 316 L. The microstructure of the Bi coatings grown on silicon and the corrosion resistance of the Bi coatings grown on AISI steel were evaluated. The microstructure was evaluated by X-ray diffraction (XRD) and the corrosion resistance was characterized by means of polarization potentiodynamic and electrochemical impedance spectroscopy. Finally the morphology of the coatings was evaluated through scanning electronic microscopy (SEM). The XRD analysis indicates that the coatings are polycrystalline; the corrosion resistance tests indicate that the films with better corrosion resistance were deposited at 40 kHz. SEM micrographs show that the coatings are grown as granular form.