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.

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.

We describe a process for the preparation of sols from water-alcohol solutions of tetraethyl orthosilicate and SnCl4. The kinetics of this process have been studied by measuring the electrical...

In this study, we designed two types of gas-sensor chips with silicon–carbon film, doped with CuO, as the sensitive layer. The first type of gas-sensor chip consists of an Al₂O₃ substrate with a conductive chromium sublayer of ~10 nm thickness and 200 Ω/□ surface resistance, deposited by magnetron sputtering. The second type was fabricated via the electrochemical deposition of a silicon–carbon film onto a dielectric substrate with copper electrodes formed by photoelectrochemical etching. The gas sensors are sensitive to the presence of CO and CH₄ impurities in the air at operating temperatures above 150 °C, and demonstrated p- (type-1) and n-type (type-2) conductivity. The type-1 gas sensor showed fast response and recovery time but low sensitivity, while the type-2 sensor was characterized by high sensitivity but longer response and recovery time. The silicon–carbon films were characterized by the presence of the hexagonal 6H SiC polytype with the impurities of the rhombohedral 15 R SiC phase. XRD analysis revealed the presence of a CuO phase.

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.

The processes of fractal structure formation have been considered in SiO₂ · SnO _x · CuO _y nanofilms prepared 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 dimensions 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.