Gradual and selective achievement of Rutile-TiO2 by thermal annealing amorphous TixOyNz films

•Amorphous (and nano/micro-crystalline) TixOyNz films prepared by sputtering served as the basis for the efficient production of TiO2 in the Rutile phase.•The structural and optical characteristics of the films (as provided by Raman scattering and optical transmission spectroscopy) show the gradual change of TixOyNz into TiO2.•The experimental results demonstrate the influence of nitrogen atoms in the TixOyNz → TiO2 transformation as well as the suitability of the proposed method in achieving crystalline TiO2 films with very well-defined structural and optical characteristics.