Optical and microstructural properties of decorative Al/Ti/TiO2 interference coatings

• Published in: Applied surface science 2017-11, Vol.421, p.794-801
• Main Authors: Skowronski, L., Wachowiak, A.A., Wachowiak, W.
• Format: Article
• Language: English
• Subjects: Aluminum; CIE Lab color space; Decorative coatings; GIMS; Interference systems; Magnetron sputtering; Titanium dioxide
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2017.03.276

•The interference color Al/Ti/TiO2 systems were produced using GIMS at industrial conditions.•The colors of samples prepared with no titanium film are not highly saturated.•A Ti layer between Al and TiO2 decreases the luminance and increases the saturation of color.•The luminance and the saturation of Al/Ti/TiO2 systems depend on the thickness of the metallic film.•The most significant changes were observed for the thickness of Ti ranging from 0nm to 20nm. This paper presents a study of the optical properties and the microstructure of interference Al/Ti/TiO2 systems obtained by gas injection magnetron sputtering (GIMS). The samples are examined by means of spectroscopic ellipsometry, atomic force microscopy and spectrophotometry combined with colorimetric measurements. The optical constants of the Al, Ti and TiO2 layers are determined and carefully studied. The thickness of dielectric films varies from 23nm to 49nm and directly determines the color of a sample from orange to blue, respectively. The thickness of Ti films ranges from 0nm to 125nm which corresponds to both the semitransparent and opaque titanium layers. The colors of the Al/TiO2 interference systems are not highly saturated because of the high reflectance of aluminum in the visible spectral range. The introduction of a Ti film between Al and TiO2 reduced the effective amount of reflected light. Moreover, the thickness of the titanium layer is associated with the color saturation of the Al/Ti/TiO2 multilayered systems.