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Vol 44, No 1 (2018)
- Year: 2018
- Articles: 9
- URL: https://journals.rcsi.science/1087-6596/issue/view/13459
Article
X-ray Fluorescence of Eu3+ Ions in Glassy and Polycrystalline Lithium Tetraborate
Abstract
The X-ray-luminescence spectra of glassy and polycrystalline lithium tetraborate Li2B4O7 activated by europium oxide Eu2O3 are studied in the spectral range of 200 to 800 nm. The luminescence observed in the wavelength region of 570 to 720 nm is caused by intraconfiguration f–f electron transitions between the levels of the first excited multiplet 5D and the main multiplet 7F of the Eu3+ ion.
1-6
One-Dimensional Photonic SiO2–TiO2 Crystals: Simulation and Synthesis by Sol–Gel Technology Methods
Abstract
The approach to synthesize one-dimensional photonic SiO2–TiO2 crystals by sol–gel methods is developed. Using the method of transfer matrices, structures consisting of 13 layers of alternating materials having the properties of one-dimensional photonic crystals with the minimal transmission coefficient of 7% in the photonic band gap range and that of 97.5% in the remaining spectrum parts are calculated and experimentally created. The positions of the photonic band gaps change along with the thicknesses of the layers of the materials composing the photonic crystal. The possibility of creating an optical filter as a result of introducing a structural defect in the form of a layer of doubled thickness is demonstrated.
7-14
Impurity Phases in Polycrystalline Films of Ferroelectric Oxides of the Perovskite-Type on the Basis of Bi2SrTa2O9 and Pb(Zr,Ti)O3
Abstract
Processes of the formation of inclusions of impurity phases in lead zirconate titanate and strontium bismuth tantalate (SBT) films by changing the excess concentration of the most volatile cation component and temperature-time regimes of their formation are studied. The conditions in which the introduction of an excess Pb content does not lead to the formation of impurity phases are selected.
15-20
Formation of Cobalt Ferrite Nanoparticles via Glycine-Nitrate Combustion and Their Magnetic Properties
Abstract
Cobalt ferrite nanoparticles, whose degree of crystallinity and particle size depends on the molar ratio of glycine to cobalt and iron nitrates, are produced by the glycine-nitrate combustion method. The highest values of the particles’ degree of crystallinity (94%) and size (77–79 nm) are observed in samples produced at a molar ratio of 0.84 of glycine to nitrates. The values of the coercive force and residual magnetization increased, together with the glycine to nitrate ratio: at 1.12, they reached 33.8 emu/g and 1350 Oe, respectively. The saturation magnetization attained the maximal value (80 emu/g) at the molar ratio of glycine to nitrates of 0.56.
21-25
Using the Sol–Gel Technology for the Treatment of Barley Seeds
Abstract
Silica sols obtained by acidic or alkaline hydrolysis of tetraethoxysilane in an excess of water or ethanol in the presence of a number of salts and/or acids are used to treat the surface of barley seeds. The surface state and the elemental composition of the seeds are studied before and after their treatment in silica sols. The conditions of the sol–gel synthesis of silica sols, their effect on the state and chemical composition of the seed surface, and the sowing characteristics are analyzed. The plant’s resistance to phytopathogen, the causative agent of root rot is studied.
26-32
RietveldToTensor: Program for Processing Powder X-Ray Diffraction Data under Variable Conditions
Abstract
The RietveldToTensor program is designed to study crystal lattice deformations using the Rietveld method from the X-ray powder diffraction data gathered under varying physical and chemical conditions. Using the program, it is possible to determine the tensor of thermal expansion, compressibility, or chemical deformations of the material. The program runs on the Microsoft Windows 7 and higher platforms.
33-40
Short Communications
Iron(III) Ion Adsorption on Macroporous Glass
Abstract
Adsorption of iron ions from diluted solutions (10−5–10−4 mol/L) of iron(III) chloride on macroporous glass (average pore radius 14.5 ± 0.6 nm) produced from sodium borosilicate glass is investigated. It is shown that the adsorption isotherm in the studied concentration range is in compliance with the Langmuir type. The limiting adsorption in the monomolecular layer and the adsorption equilibrium constant are determined.
41-46
Effect of the Nature of the Binder on the Formation Temperature of Glass-Ceramic Coatings Based on Si–B–ZrB2 for Graphite Protection
Abstract
This work is devoted to fabricating and studying the properties of coatings based on the Si–B–ZrB2 systems used in graphite protection. The kinetics of the oxidation of graphite with coatings at different temperatures in air are investigated. The optimal conditions for the thermal treatment of the material with the coating are suggested.
47-50
Preparation of Pure Amorphous As2S3 Films of a Stoichiometric Composition
Abstract
The results of studying the composition of arsenic trisulphide (As2S3) films obtained by adding finely dispersed copper or silver powders to the starting materials for sputtering or by using triple compositions As–S–As and As–S–Cu are presented. The issues of preserving the composition of the films obtained and the degree of their purity are discussed.
51-53