A new design of decorative tungsten oxide coatings is presented. The coatings were deposited with gradient refraction index by magnetron sputtering from a tungsten target and pulsing the reactive gas. The controlled injection of the reactive gas can produce a gradient concentration profile from pure tungsten to tungsten trioxide determining the final apparent colour of the coating. A dynamic sputtering model was built to simulate the coating growth during the reactive gas pulsing which was validated by the direct measurement of the oxygen content gradient in the deposited coatings. Finally these results were used for an optical model allowing describing the optical properties of the deposited tungsten oxide layer, again validated by experimental analysis. This procedure allows depositing coatings with a desired colour by using the models for finding the optimal oxygen pulse parameters. This proposed method can be easily applied to almost any metal/metal oxide system.
