The SiO2ZrO2 composite films were prepared by means of sol-gel technology and characterized by scanning electron microscopy, energy dispersive X-ray (EDX) analysis, and X-ray diffraction. The presence of the stable monoclinic ZrO2 with an impurity of tetragonal phases is shown. The film surface is characterized by the presence of ZrOCl2·6H2O or ZrCl(OH)/ZrCl(OH)2 grains. The crystallite size negligibly depends on the annealing temperature of the film and amount to 10–12 nm and 9–12 nm for the films thermally treated at 200 °C and 500 °C, respectively. The film’s resistance is rather sensitive to the presence of NO2 impurities in the air at a low operating temperature (25 °C). Accelerated stability tests of the initial resistance showed high stability and reproducibility of the sensor based on the SiO2ZrO2 film thermally treated at 500 °C.

The processes of fractal structure formation have been considered in SiO 2 ⋅ SnO x ⋅ CuO y nanofilms pre pared by the sol-gel method from a tetraethoxysilane alchohol solution modified by metal salts. The atomic force microscopy images of these films have been obtained. The surface morphology has been analyzed using the Takens embedding method and Grassberger-Procaccia algorithm. The correlation and fractal dimen sions of the film samples and the coefficient of surface area increase have been calculated. The effects of the annealing temperature and concentration of the doping component on the formation of fractal structures in the materials under study have been estimated.

Silicon-carbon films have been deposited on silicon and Al2O3/Cr-Cu substrates, making use of the electrolysis of methanol/dimethylformamide-hexamethyldisilazane (HMDS) solutions. The electrodeposited films were characterized by Raman spectroscopy and scanning electron microscopy, respectively. Moreover, the nucleation and growth mechanism of the films were studied from the experimental current transients.

Phone: þ7 928 771 66 57, Fax: þ7 863 297 51 20Copper-containing thin films were synthesized by a citrate sol-gel method using ethylene glycol. The evolution of the shape and local atomic structure of the copper-containing fractal crystallites at different stages of growth was investigated by the combination of experimental and theoretical techniques. A surface morphological study of the deposited film samples was carried out using SEM. It revealed the evolution of the crystallite structures as a function of annealing temperature. To describe this mechanism diffusion-limiting aggregation and cluster-cluster models were used. X-ray absorption spectroscopy (XANES) was applied to show the dynamics of the local atomic structure of Cu ion and the copper oxidation state at different stages of crystallites formation. It was found that at temperatures up to 250 8C the Cu 2 Cl(OH) 3 (atacamite phase) and chelate complex are formed. With temperature increases changes in the local atomic structure as well as in morphology take place and at 500 8C CuO formed. As a result of these processes, the fractal organization of the other level was observed.

The citrate sol–gel method was utilized for the fabrication of copper-containing films sensitive to NO2 gas. Effect of annealing temperature on the film phase composition, morphology, and sensor response was studied. X-ray diffraction reveals the formation of Cu2Cl(OH)3 phase at 250 °C and the CuO phase at 350 and 500 °C. It was found out that the films annealed at 250 °C and 350 °C showed the best sensor characteristics. The influence of thermal degradation on the probability of percolation effect in films and its connection to a decrease of gas sensitivity was studied. The kinetics of the NO2 gas adsorption on the film’s surface was described following the Elovich model. Activation energy estimated from the ln(S) vs. 1/T plots was 252 and 30 kJ/mol for the films annealed at 250 and 350 °C, respectively.