Samarium Additive Effect onto the Nickel Electrodeposition Process

Abstract

In the present work, nickel-samarium coatings (Ni-Sm) with 1.88% of samarium were obtained by electrodeposition from a nickel electrolyte composed of (NH2HSO3, Ni(CO3)2 and H3BO3) and containing Sm2(SO4)3. The electroactivity intervals of each component of the electrolytic bath and the effect of samarium (III) on the nickel electroplating process were studied by cyclic voltammetry and by electrochemical impedance spectroscopy (EIS). The results indicate that H3BO3 and Sm2(SO4)3 added to the electrolytic bath are both reduced during the nickel electroplating. The Ni-Sm coatings were characterized using scanning electron microscopy (SEM), X-ray Diffraction (XRD), X-ray fluorescence (XRF) and X-ray photoelectron spectroscopy (XPS). The results indicate that the samarium species incorporated in the nickel coatings are found as Sm(III) and Sm(II) hydroxides or oxides.