Vol 42, No 5 (2016)

It has been found that the temperature dependence of the intensity of the polarized V_v and depolarized H_v components of light scattering by a boron oxide melt in the range of 300–450°C is characterized by the existence of hysteresis: the specific feature of the change in the polarized V_v component is the formation of a minimum, while the specific feature in the behavior of the depolarized H_v component is associated with the appearance of a maximum in the sample heating mode; the cooling mode is accompanied by a monotonic change in the intensity of the light-scattering components. It has been found also that in the process of a low-temperature stabilization of the melt at 300°C, the polarized V_v component after reaching its minimum values increases up to the initial level, while the depolarized H_v component after passing its maximum decreases to the values smaller than the initial one. The characteristic time of the change in the intensity of the V_v component at 300°C is determined; its value was found to be ~100 min. It has been shown that an insignificant change in the melt synthesis conditions affects the detected features of the intensity change in the range of 300–450°C.

The strength of dual-display glass surfaces 0.64 mm (Corning 1737 glass) and 0.70 mm (Eagle²⁰⁰⁰ glass) thick is measured in the initial state and after annealing. Large dispersion of the strength of the glass before and after annealing is found. It is suggested that the low values of the strength are caused by the adverse conditions of storing and handling glass samples.

The recent accomplishments in using Sn or Ge, Mn and Ti-doped hematite photoanodes for solar water splitting are highlighted in this paper. Magnetron sputtering and hydrothermal methods were applied for depositing the alloyed films on Fluorine doped Tin Oxide (FTO) glasses. Results were compered by structural and morphology analysis using scanning electronic microscopy (SEM) images and XRD. Similarly, a comparison was done by using optical properties and photocatalytic activities. Doping elements for all samples illustrated higher photocurrent density to compare un-doped hematite. This research confirms that doped elements enhance the charge carriers and reduce the recombination losses, and it emphasizes that these treatment results in better photoelectrochemistry performance of Fe₂O₃ nanostructured photoanodes.

The analysis of the stochastic model of a nanocluster of a smoky quartz composition (cairngorm) is performed at low temperature relaxation. The structure and coordination characteristics of the cairngorm’s nanoparticles as one of the most likely scenarios for the relaxation by the Monte Carlo method are determined.

Thermodynamic modeling of the deposition of condensed phases of complex composition has been carried out in the Si–C–N–Fe–H–(He) system in the temperature range of 500–1300 K under total pressure of 10^–2–10^–1 Torr in the system using initial gas mixture of tris(diethylamino)silane HSi[N(C₂H₅)₂]₃, ferrocene (C₅H₅)₂Fe, and helium. Derived from the results of thermodynamic modeling, the method for the preparation of SiC_xN_yFe_z films using the high-temperature decomposition of the gas mixture of TDEAS, ferrocene, and helium at low pressure in the temperature range of 1073–1273 K has been developed. The dependence of the chemical and phase composition of the films on the conditions of synthesis has been determined using various methods of chemical analysis such as IR spectroscopy, Raman scattering, scanning electron microscopy, energy dispersion spectroscopy, X-ray phase analysis using synchrotron radiation, and X-ray photoelectron spectroscopy (XPS). The magnetic properties of the films have been studied by Faraday’s method and electron paramagnetic resonance. It has been shown that the films are paramagnetic at the temperature of synthesis of 1123 K, while at the deposition temperature of 1273 K they are ferromagnetic. The mechanical properties of the films were characterized by nanoindentation technique.

A highly dispersive powder with a (ZrO₂)_0.92(Y₂O₃)_0.03(Gd₂O₃)_0.03(MgO)_0.02 composition and specific surface area of 150 m²/g has been synthesized via a method of coprecipitation of hydroxides with the subsequent cryochemical treatment of the gel. Nanoceramics based on the cubic modification of zirconium dioxide with the grain size of ~40–45 nm have been obtained. The temperature dependence of the specific electrical conductance of the nanoceramics within a temperature range of 350–870°C in air has been studied, and the ratio of the ionic and electronic parts of the conductance has been determined. Recommendations for the use of the obtained oxide nanocomposite as an electrolyte for a high-temperature fuel cell have been given.

Zeolite of the calcium-containing gmelinite type was synthesized based on the halloysite, dolomite, and obsidian minerals. The cation-exchange, dehydrating, and rehydrating properties of zeolite were studied and the oxygen exchange was calculated.