Identifying Key Factors towards Highly Reflective Silver Coatings

Abstract

This paper attempts to identify key factor(s) for highly reflective silver (Ag) coatings. Investigation was made over the crystal orientation and surface roughness, using several types of surfaces, including electroplated Ag polycrystal films, physical vapour deposited polycrystal Ag films, and single crystal Ag foils with different crystal orientations. In each type of the surfaces, surface roughness was varied so that, for different combinations of crystal orientation, roughness would elucidate the key factors towards highly reflective Ag coatings. It is found that surface roughness plays a critical role in determining the reflectance, while the crystal orientation has negligible effect. The mean reflectance and one-way ANOVA analysis indicate that the single crystal Ag foils with three orientations performed statistically the same in the same roughness group at significance level = 0.05. Moreover, correlation between the surface reflectance and surface roughness has been proposed for the benefit of coating design. Refection data obtained from the polycrystalline silver samples are used to verify the accuracy of the proposed correlations. It was observed that the development surface area ratio, , is a better roughness indicator in predicting the reflectance of polycrystalline silver films than the arithmetic average roughness, .

Relation between Color and Surface Morphology of Electrodeposited Chromium for Decorative Applications

“…Therefore, if the roughness is increased during layer growth, the decrease of reflectance is higher in the blue-green range of the spectrum than in the yellow-red range, which is in good agreement with the results discussed above. Similar conclusions on roughness-dependent reflectance were drawn for electroplated nickel, 25 copper 26 and silver, 27 but with measuring the intensity of reflected light under directional illumination. In all cases, a loss of brightness was observed when the average roughness exceeded a threshold value.…”

A New Measuring System for the Determination of the Ice Adhesion Strength on Smooth Surfaces

“…The roughness values were determined over an area of 10 × 10 μm 2 . The developed interfacial area ratio (SDR) is defined as the ratio of developed 3D surface area to the planar area It represents the additional surface area contributed by the roughness compared with the area of totally flat surface, and the SDR as well as the R a and R z values were calculated by AFM package software.…”

“…The developed interfacial area ratio (SDR) is defined as the ratio of developed 3D surface area to the planar area. 38…”

Properties and Colorimetric Performance of Screen-Printed Thermochromic/UV-Visible Fluorescent Hybrid Ink Systems

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