卷 68, 编号 5 (2023)

A new method for the production of LuFeMgO4 based on the combustion reaction of a gel-like precursor prepared from metal nitrates and fossil fuels has been proposed. The possibility to prepare this oxide from stoichiometric compositions of metal nitrates with polyvinyl alcohol (PVA) and glycine has been studied. The adiabatic combustion temperatures Tad have been estimated for the systems under consideration. The combustion products of PVA-nitrate and glycine-nitrate compositions before and after their heat treatment have been studied using X-ray diffraction analysis and IR spectroscopy. It has been established that the combustion reaction products of the PVA-nitrate composition are an X-ray amorphous powder, while those of the glycine-nitrate composition are a mixture of nanocrystalline oxides containing 52.5 wt % LuFeMgO4. According to X-ray diffraction and SEM data, 4-h annealing of this mixture at 1300°C leads to the formation of a single-phase LuFeMgO4 powder with a layered microstructure and a grain size of about 1–2 μm.

The InSb + 1 at % Ni + 1 at % Mn alloy was studied by optical microscopy and scanning electron microscopy. A Heusler phase based on NiMnSb in the form of microinclusions on InSb dislocations was detected. The chemical composition of the microinclusions on dislocation pile-ups ranges from Ni1.1MnSb to Ni1.2MnSb, and that on individual dislocations is close to Ni1.1MnSb. However, the synthesis gives rise to bulk structural defects in the form of micropores and to elastic deformations around them, which are the main obstacles to the creation of a coherent material with unhindered movement of polarized electrons throughout the volume.

Magnesium–aluminum layered double hydroxides and mixed oxides based on them were obtained by high and low supersaturation methods and analyzed. It was shown that the phase composition and formation of nano-sized particles with a large surface area is significantly affected by the rate of introduction of magnesium–aluminum systems into the medium of the precipitated material. All of the obtained samples were studied by thermogravimetric analysis with mass-spectrometric detection, X-ray diffractometry, scanning electron microscopy, energy dispersive X-ray spectroscopy, and infrared spectroscopy.

The atmospheric pressure melting points of binary halides ABHal3, ABHal4, A2BHal4, A2BHal5, and A3BHal6 (A and B are various elements; Hal = F, Cl, Br, or I) were predicted. Calculations were made using our developed system of machine learning. Computer models were searched by analyzing information on the already known melting points of halides. The unknown melting points of the halides were predicted using only the values of the properties of the elements A, B, and Hal. It was shown that the programs based on the methodology of ensembles of machine learning algorithms make the most accurate estimates of melting points (the mean absolute errors determined by the cross-validation method in the leave-one-out cross validation mode were in the range of 29–52 K, depending on the halide composition and the chosen algorithm). The coefficient of multiple determination for the models used for prediction was no lower than 0.7.

A structure–property correlation was developed that makes it possible to choose the optimal values of the standard heat capacity of alkali metal borates, for which, according to the data of various experimental works and reference publications, wide variations are observed. This correlation enables one to estimate the standard heat capacity of unstudied alkali metal borates with sufficient validity. To ensure the reliability of the correlation, a critical analysis was made of the initial data taken from reference publications and original experimental works. Our own processing of experimental measurements of the heat capacity and the enthalpy increment was performed to verify the reliability of the literature values of the standard heat capacity of alkali metal borates.

The paper describes the thermodynamic modeling and experimental study of the synthesis of vanadium oxide films at various temperatures from the tetrakis(ethylmethylaminovanadium) V[NC3H8]4 precursor in the presence of oxygen in an argon atmosphere. The thermodynamic modeling was carried out using the calculation of chemical equilibria based on the minimization of the Gibbs energy of the system. In the experimental part of the paper, the films were synthesized by the atomic layer deposition procedure. The thermodynamic modeling and experimental results agree with each other and can be used to develop procedures for the synthesis of film coatings based on vanadium oxides.

Extraction of uranium, thorium, and lanthanide(III) ions from nitric acid solutions with mixtures of dinonylnaphthalenesulfonic acid and N-(diphenylphosphoryl)-N'-n-propylureas containing imidazolyl, diethylamino, pyrid-2-yl, and 2-oxopyrrolidine fragments has been studied in organic solvents. Considerable synergetic effect on extraction of metal ions with mixtures of dinonylnaphthalenesulfonic acid and N-(diphenylphosphoryl)-N'-[3-(2-oxopyrrolidino)propyl]urea has been revealed. Stoichiometry of extracted complexes has been determined. Effect of extractant strucuture, organic diluent nature, and HNO3 content in aqueous phase on extraction efficiency of metal cations into organic medium has been accessed.

A procedure was developed for the single-step synthesis of a metal–polymer nanocomposite based on silver nanoparticles and second-pseudogeneration superbranched polyester functionalized along the periphery with 3-[(2-aminoethyl)amino]propionate. Under the conditions of the synthesis in the medium of H2O or DMSO, hyperbranched polyester decorated with ethylenediamine moieties can act as both a reductant of the nanoscale silver state and a stabilizer of it. The synthesized composite nanomaterial is formed by aggregates of hyperbranched polyester polyamine doped with Ag(0) nanoclusters and nanoparticles of spheroidal symmetry with a face-centered cubic crystal lattice. The hydrodynamic diameter of aggregates and the diameter of particles increase with increasing molar ratio 
 and are 34–90 and 7–14 nm, respectively.

Приведены сведения о совещаниях и конференциях по физико-химическому анализу, проведенных ранее в СССР и Российской Федерации. Охарактеризована научная деятельность Н.С. Курнакова и его учеников в период работы в Петербургском политехническом университете. Рассмотрены результаты исследований различных неорганических и органических систем, направленных на синтез новых веществ и материалов и новых технологических процессов, выполненных в Российской Федерации и за рубежом в последние годы.