Titanium derivatives structural parameters

Like Al-based fluorides, the [HF] content expressed as the R = [HF]/[Ti] molar ratio, is a decisive parameter for the final crystallized forms. Using oxychloride (TiOCU.xHCl) as titanium precursor, the variation of the [HF] content leads to the stabilization of three phases (Figure 2.15) (i) for R = 0.2, the anatase-type structure, (ii) for R = 1.7, a new phase adopting a derived-HTB type structure and finally, (iii) for R = 3 a superstructure of the ReOs form. The two latter phases are obtained at T = 90 °C. On the other hand, the fluorine-doped anatase is obtained at higher temperature, that is T = 150 °C. The composition, structural features and UV-absorption properties of Ti oxy-hydroxy fluorides are detailed in chapter 8 of this book by A. Demourgues, L. Sronek and N. Penin. ... 

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