Investigation and evaluation of structural color of TiO2 coating on stainless steel

Titanium dioxide (TiO2) thin films were deposited on the stainless steel substrates by RF magnetron sputtering. In order to prevent film delamination and cracking caused by thermal mismatch between the stainless steel and TiO2 thin film, Ti thin film was initially deposited on the stainless steel as buffer layer. The experimental results have indicated that optical characteristic in the visible region were strongly influenced by the thickness of TiO2 thin film. In order to estimate and compare with the experimental results, the simulation program, the Essential Macleod Program was adopted. Based on the simulation results, 4 different colors such as dark goldenrod, medium orchid, medium blue and dark green were fabricated with various deposition times respectively. The color of the multilayer film indicating (L*, a*, b*) = (52.93, −40.69, 7.69) deposited for 209 nm thickness was visually observed as dark green color with the maximum peak of 31.54% spectral reflectance at a wavelength of 510 nm, corresponding to the simulation results.