Electrochemical Impedance Spectroscopy Studies of Protected Silver Reflectors Deposited by Magnetron Sputtering

摘要

Dielectric protected silver reflectors were deposited by magnetron sputtering on highly polished stainless steel substrates to obtain high reflectivity in the visible range. In this paper, we focused on the ageing of the reflectors and their durability. Electrochemical Impedance Spectroscopy experiments were carried out to test the protective layer. An equivalent electric circuit models the coating. With this method, we can quantify the ability of protection against corrosion for the dielectric film by a resistance value R_f. We compared results with accelerated ageing experiments in order to establish some correlations between both methods.