Environmental durability of protected silver mirrors prepared by plasma beam sputtering.

Various overcoat layers have been developed to protect silver mirrors from tarnish and corrosion. However, the mechanisms by which these protective layers improve mirror durability are not fully understood. Mixed flowing gas exposure was used to investigate the corrosion behavior of plasma beam sputtered silver mirrors with different adhesion layer materials. A small amount of nickel in the adhesion layer had a significant impact on the silver-dielectric interface. Additionally, lateral transport of silver was found to be an important factor in the corrosion process. Better stability at all layer interfaces is suggested to improve mirror durability.

[1]  Maxime Boccas,et al.  Protected-silver coatings for the 8-m Gemini telescope mirrors , 2006 .

[2]  S F Pellicori.  Scattering defects in silver mirror coatings. , 1980, Applied optics.

[3]  G. Hass,et al.  Reflectance and preparation of front-surface mirrors for use at various angles of incidence from the ultraviolet to the far infrared , 1982 .

[4]  Chung-Tse Chu,et al.  Control of stress in protected silver mirrors prepared by plasma beam sputtering. , 2011, Applied optics.

[5]  Andreas Tünnermann,et al.  Description of particle induced damage on protected silver coatings. , 2015, Applied optics.

[6]  Chung-Tse Chu,et al.  Corrosion characterization of durable silver coatings by electrochemical impedance spectroscopy and accelerated environmental testing. , 2006, Applied optics.

[7]  David A. Sheikh.  Improved silver mirror coating for ground and space-based astronomy , 2016, Astronomical Telescopes + Instrumentation.

[8]  Mark E. Orazem,et al.  Interpretation of Electrochemical Impedance for Corrosion of a Coated Silver Film in Terms of a Pore-in-Pore Model , 2014 .

[9]  W. Abbott.  The development and performance characteristics of mixed flowing gas test environment , 1988 .

[10]  Harold E. Bennett,et al.  Formation and Growth of Tarnish on Evaporated Silver Films , 1969 .

[11]  David P. Taylor,et al.  Accelerated atmospheric corrosion testing of electroplated gold mirror coatings , 2010 .

[12]  Thomas E. Graedel,et al.  Corrosion Mechanisms for Nickel Exposed to the Atmosphere , 1989 .

[13]  Nobuhiko P. Kobayashi,et al.  Corrosion barriers for silver-based telescope mirrors: comparative study of plasma-enhanced atomic layer deposition and reactive evaporation of aluminum oxide , 2015 .

[14]  H. E. Bennett,et al.  Effect of atmospheric exposure on the infrared reflectance of silvered mirrors with and without protective coatings. , 1973, Applied optics.

[15]  Norman L. Thomas,et al.  UV-shifted durable silver coating for astronomical mirrors , 2000, Astronomical Telescopes and Instrumentation.

[16]  J. Daniel,et al.  Progressive changes in microstructure and composition during degradation of solar mirrors , 1980 .

[17]  H A Macleod,et al.  Progress in the development of a durable silver-based high-reflectance coating for astronomical telescopes. , 1985, Applied optics.

[18]  James D. Barrie,et al.  Optical Properties and Corrosion Resistance of Durable Silver Coatings , 1998 .