130 nm, ~20 X & ±1 ) and SiO 2 (~15 nm) films. The deposition was performed by RF sputtering in 2.5 deposition cycles (1 cycle » 0.8 lm) at a deposition rate of 1.5 nm s ±1 and a pressure below 1.0 10 ±5 torr. Aluminum anodization was carried out in a 10 % phosphoric acid solution at 130 V and 7 C. The TiO 2 sol (Sol. A, ~5 wt.-%) was prepared with titanium tetraisopropoxide, acetylacetone, distilled water, and ethanol at a mole ratio of 1:1:3:20, and the SiO 2 ±TeO 2 sol (Sol. B, ~5 wt.-%) with tetraethyl orthosilicate, telluric acid, ethanol, H 2 O, and HCl at a mole ratio of 1:0.2:20:4:0.03. The composite TiO 2 ±SiO 2 ±TeO 2 sol was produced by adding 5±20 wt.-% of Sol. B to Sol. A. Other details of the sol synthesis are the same as in reference [21]. The morphology and the structural characteristics of the specimens were investigated by field emission scanning electron microscopy (FESEM) (S-5000, Hitachi), TEM (JEOL-100 kV), XRD (RINT-2200 V/PC, Cu Ka, 40 V/40 mA), and UV-vis spectrometry (U-3500, Hitachi). For TEM observation, the alumina/titania composite layers stripped from the substrates were embedded into epoxy resin and cut using an ultramicrotome (LKB-2088 /V) with a diamond knife into ~60 nm thick slices. The sliced samples were set on carbon-coated copper micro-grids and observed in the bright field mode along with the corresponding diffraction patterns.