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Titanium dioxide (TiO2) thin films were deposited by RF magnetron sputtering on glass and silicon substrates at different substrate temperatures (20, 100, 200 and 300 °C). The structural and morphological characteristics of the films were investigated by X ray Diffractometry (XRD) and Atomic Force Microscopy (AFM) while the optical properties of the films were studied by optical spectroscopy. It was shown that at room temperature, TiO2 films grown on glass were amorphous following the substrate structure. At higher temperatures, XRD detected only a nanocrystalline rutile TiO2 structure. This indicated that the transition temperature toward the most stable TiO2 phase was obtained from 100 °C and the crystallinity was enhanced at higher growth temperature. For TiO2 films grown on Si substrates, only a nanocrystalline anatase TiO2 structure was obtained at room temperature. At higher temperatures, we noticed the appearance of other secondary phases related to rutile, anatase and brookite structures. From AFM images, we noticed that at room temperature, the films were porous. With increasing the temperature, the structure of the films became crystallized showing a columnar structure. Film growth and structural properties were discussed in terms of the Thornton model. From optical analysis, the films were transparent with an indirect band gap and a refraction index which reached 3.09 eV and 2.7, respectively. The reflectance and transmittance spectra showed, not only that there was a little translation from UVB to UVA and near‐visible range, but also a decrease of reflection with a temperature increase indicating that the films could be used as anti‐reflection coatings. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

A biomimetic cellulose I nanolayer with a parallel chain alignment was successfully designed through the chemoselective modification of cellulose and self‐assembly of its thiosemicarbazone on a gold substrate (see figure). This is the first time replication of the crystalline structure of native cellulose, that is, cellulose I, in the layer state has been achieved.

TiO2 films were prepared using radio frequency (RF) magnetron sputtering and were deposited on glass and Si substrates. We varied deposition time at room temperature with RF density of 3.7 W/cm2 and argon flow rate of 4 sccm. The morphological, structural, optical and electrical properties were studied by Atomic Force Microscope (AFM), X ray Diffractometer (XRD) and UV-VIS-NIR spectrophotometer. The transmittance is maintained in the range of 70- 90% in the visible and near-infrared range, high refractive index of 2.4 and large direct band gap of about 3.5 eV are obtained. These films are annealed at 300°C during 2 hours. The annealing effect is investigated in this work. The results of this study suggest that the variation of the deposition time allow the control of the structural, optical and electrical properties of the films.