bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies of Dynamics of Neutral Component of Current Sheet Plasma, Based on Spectral Broadening of Helium Line He I 5876 Å
Authors: Kyrie N. P. , Kharlachev D. E. , Shpakov K. V.
Published: April 2024

Spectroscopy methods were used for studying the dynamics of neutral plasma component in current sheets formed in two-dimensional (2D) and three-dimensional (3D) magnetic configurations during discharge in helium. It has been ascertained that when the current sheet is formed in the 2D magnetic field, flows of fast suprathermal helium atoms appear in it, which are directed along the current sheet width (the largest of the sheet transverse dimensions). It is shown that helium atoms can acquire the directed energy Wx due to the resonance charge exchange of accelerated ions in the current sheet plasma. The energy of directed motion of helium atoms can reach Wx ≈ (480 ± 120) eV, which is ~20 times higher than the temperature of helium atoms Ta ≈ (20 ± 2) eV at the same times. During the current sheet formation in the 3D magnetic configuration, fast helium atoms were not observed.
Neutral Injection Complex for Globus-M2 Spherical Tokamak
Authors: Shchegolev P. B. , Minaev V. B. , Tel’nova A. Yu. , Varfolomeev V. I. , Gusev V. K. , Esipov L. A. , Zhil’tsov N. S. , Kolmogorov V. V. , Kondakov A. A. , Kurskiev G. S. , Miroshnikov I. V. , Panasenkov A. A. , Sorokin A. V. , Shikhovtsev I. A.
Published: April 2024

The injection complex that heats plasma of Globus-M2 spherical tokamak consists of two injectorswhich supply high-energy beams of hydrogen (deuterium) atoms into the device’s plasma. Injectors areautonomous and allow for preparing and setting up the device and measuring the parameters of the atomicbeam independently of the other injector and of the tokamak. The authors provide detailed analysis of eachinjector’s configuration, substantiate their selection of the experiment layout for introducing beams into thetokamak plasma, set forth characteristics of both injectors’ atomic beams injected into the tokamak plasma,and discuss the results of experiments on additional heating of Globus-M2 tokamak plasma obtained byinjecting two atomic beams.
Effect of the Platinum Mass Content in a Catalyst and the State of the Support Surface on the Path of the Oxygen Reduction Reaction in Alkaline Electrolyte
Authors: Vernigor I. E. , Bogdanovskaya V. A. , Radina M. V. , Andreev V. N.
Published: April 2024

The effect of the support nature and the mass of platinum on the stability, electrochemical characteristics of monoplatinum catalysts, and the reaction path of electrochemical oxygen reduction in alkaline electrolyte is studied. Catalysts with the Pt mass content of 10, 20, 40, 60 wt % are synthesized by the polyol method on carbon nanotubes functionalized in NaOH and doped with nitrogen. The activity, the percentage of hydrogen peroxide formed, and the number of electrons participating in the oxygen reduction reaction are determined from the data obtained by the rotating ring-disk electrode method. For catalysts synthesized on the nitrogen-doped carbon nanotubes, the highest selectivity in the reaction of oxygen reduction to water is observed; the higher Pt surface area at the electrode, the greater is the selectivity, because the contribution of the support surface to the total oxygen reduction reaction decreased. Both the presence of hydrogen peroxide and a decrease in stability result from the decrease in the platinum content in the catalyst.
Comparative Study of Biocatalytic Oxidation of Some Organic Substrates Using Shewanella xiamenensis and Escherichia coli Microorganisms on Mediator and Non-Mediator Bioanodes
Authors: Kazarinov I. A. , Meshcheryakova M. O.
Published: April 2024

In the work, a comparative assessment of the effectiveness of Shewanella xiamenensis and Escherichia coli microorganisms used as a biocatalyst in the process of bioelectrochemical oxidation of various substrates in neutral media on mediator-free and mediator bioanodes was carried out. It was shown that the rate of bioelectrochemical oxidation of the studied organic substrates (citric acid, glucose, sucrose) with the help of S. xiamenensis cells does not depend on the concentration of the mediator introduced into the system (methylene blue)—electron transfer from cells to the electrode occurs as a result of direct contact of cells with the electrode’s surface. A comparative kinetic analysis showed that S. xiamenensis cells are a less effective biological catalyst for the process of glucose oxidation compared to the E. coli microorganism (in the presence of a mediator). The kinetic characteristics of the glucose oxidation reaction in the “mediator–substrate–E. coli cells” system were determined. It was found that the order of the oxidation reaction with respect to glucose at the anode is equal to one, the rate constant of this reaction is 0.0214 min–1, and the half-life of glucose is 33 min. It is shown that the model system under study makes it possible to lower the concentration of glucose in the working solution to the value of the background current, which indicates an almost complete purification of the solution from the organic substrate. It is shown that in solving practical problems in order to increase the efficiency of wastewater treatment from organic substances using mediator-free bioanodes, it is necessary to search for new cells, including other cells of the Shewanella genus, with mandatory immobilization of cells on the electrode surface in order to increase electrical contact.
Transport Properties of In3+- and Y3+-Doped Hexagonal Perovskite Ba5In2Al2ZrO13
Authors: Andreev R. D. , Anokhina I. A. , Korona D. V. , Gilev A. R. , Animitsa I, E.
Published: April 2024

A complex oxide Ba5In1.9Y0.1Al2ZrO13 with hexagonal perovskite structure (a = 5.971(4) Å, с = 24.012(1) Å) is prepared for the first time. The phase is found to dissociative-absorb water from gas phase, the degree of hydration being as high as 0.39 mol Н2О. It was found by using IR-spectroscopy that protons are present therein as energetically nonequivalent ОН–-groups involved in hydrogen bonds of diverse strength. Isovalent yttrium-doping of the Ba5In2Al2ZrO13 phase is shown not to lead to any valuable change in the oxygen-ion-conductivity as compared with the Ba5In2.1Al2Zr0.9O12.95 acceptor doping that allows increasing the oxygen-ion-conductivity by a factor of 1.3. Both types of doping lead to increase in the proton conductivity and, as a corollary to this, an increase in the proton concentration. For these phases the degree of hydration depends on the cell parameters, hence, is determined by space availability for ОН–-groups in the barium coordination. Proton transport dominates in the Ba5In2Al2ZrO13, Ba5In2.1Al2Zr0.9O12.95, and Ba5In1.9Y0.1Al2ZrO13 phases below 600оС in humid atmosphere (pH2О = 1.92 × 10–2 atm).
Nanosized Complex of Metal–Ion-Exchanger Composites in the Oxygen Electrochemical Reduction
Authors: Kravchenko T. A. , Krysanov V. A. , Golovin I. A.
Published: April 2024

The role of primary (the particles’ size) and secondary (the particles’ content in the material) size effects of metal–ion-exchanger composites in the oxygen electrochemical reduction is elucidated. To this purpose, metal–ion-exchanger particulate composites with different grain size and the metal (Cu) particles’ content are prepared as spherical grains, based on macroporous sulfonic cation-exchange matrix (Lewatit K 2620). X-ray diffraction analysis showed the deposited metal basic particles to be nanosized. A special feature of the metal particles is that during the repeated cycles of their chemical deposition into the ion-exchange matrix pores both the capacity ε, and the particles’ radius r0 increased. On this reason, the primary and secondary size effects appeared being interconnected in a common nanosized complex f=ε/r0. With the increasing of the capacity the complex increased up to certain limiting value, which is connected with percolation transition from separate metal clusters to collective associates. Correspondingly, the reduced oxygen specific amount also reached its constant value. The oxygen electroreduction process reached quasi-steady-state regime.
Properties of Li1.3Al0.3Ti1.7(PO4)3 Lithium-Conducting Ceramics Synthesized by Spark Plasma Sintering
Authors: Kunshina G. B. , Shichalin O. O. , Belov A. A. , Papynov E. K. , Bocharova I, V. , Shcherbina O. B.
Published: April 2024

Results on the synthesis of lithium-conducting ceramics Li1.3Al0.3Ti1.7(PO4)3 by the method of spark plasma sintering (SPS) are presented. In the first stage, the monophase Li1.3Al0.3Ti1.7(PO4)3 solid-electrolyte powder is synthesized from the nitrate-peroxide precursor. Its subsequent consolidation by the SPS method provides the formation of ceramics with the high Li-ionic conductivity and the density on the level of 97–98%. The microstructure and the electrochemical properties of the Li1.3Al0.3Ti1.7(PO4)3 ceramics are studied.
Oxygen-Ionic Conductivity in Isovalent-Doped Layered BaLaInO4-Based Perovskites
Authors: Bedarkova A. O. , Cheremisina P. V. , Abakumova E. V. , Fedorova I. S. , Davletbaev K. G. , Tarasova N. A. , Animitsa I. E.
Published: April 2024

The oxygen-ionic conductivity of isovalent-doped complex oxides characterized by the Ruddlesden–Popper structure is studied. The BaLa0.9Nd0.1InO4 sample was obtained for the first time by substitution in the La sublattice, and its transport properties are studied. A comparing of the results with the data for samples obtained earlier by isovalent substitution in the In-sublattice of BaLaInO4 is presented. The introducing of a dopant is shown to lead to increase in the contribution from oxygen-ionic conductivity and also in the total conductivity by ~2 orders of magnitude.
Specific Features of the Electronic Structure of Oxygen-Deficient Perovskites SrFe1 – xMoxO3 – y
Authors: Gainutdinov I. I.
Published: April 2024

By using the VASP package, within the framework of the DFT approach, the properties of the ground state of the SrFe1 – xMoxO3 – y oxide with the perovskite structure are calculated for the various values of molybdenum content and oxygen nonstoichiometry. It is shown that the doping procedure as well as the procedure of varying the oxygen content give rise to changes in the charge stage of oxygen ions in the system, which is accompanied by a shift of the Fermi level with respect to the invariant band structure (rigid band model) and the transition to the semimetal conduction type.
A New Desiccant Based on Graphene Oxide for Deep Dehydration of Electrolytes for Electrochemical Cells
Authors: Puntusova L. A. , Kornilov D. Yu.
Published: April 2024

A material based on graphene oxide is considered as a desiccant of aprotic solvents in nonaqueous electrolytes containing lithium salts. Three methods are proposed for preparation of final materials with different number and volume of pores. The effect of the initial parameters of hydrogel such as its pH and the concentration of solid substance is studied. Dependences of the adsorption capacity of desiccant on its porosity are plotted. The prospects of this new desiccant in dehydration of lithium electrolytes are discussed as compared with commercial molecular sieves.
The Effect of the Working Electrode Material Based on Pt/SnO2(Sb) on the Properties of Hydrogen and Carbon-Monoxide Sensors
Authors: Shmygleva L. V. , Starkov A. V. , Leonova L. S.
Published: April 2024

The effect of the platinum content (3–10 wt %) in the Pt/SnO2(Sb)-based working-electrode material on the properties (sensitivity, high-speed performance, recovery time) of solid-state potentiometric gas sensors for hydrogen and carbon monoxide including their simultaneous presence in air is studied. Sensors with 5% Pt demonstrate the best characteristics: the efficient carbon-monoxide detection for its concentration from 0.01 to 1 vol %; no effect of hydrogen present in the CO + air mixture in concentrations comparable with the CO concentration; the shortest relaxation time (~30 s at 1% CO).
THE INFLUENCE OF MECHANO ACTIVATION ON THE STRUCTURE AND ELECTRICAL CONDUCTIVITY IN THE SYSTEM KNO3-Al2O3
Authors: Akhmedov M. A. , Gafurov M. M. , Rabadanov K. Sh. , Ataev M. B. , Amirov A. M. , Kubataev Z. Yu. , Kakagasanov M. G.
Published: April 2024

In this paper, the effect of mechanical activation on the structure and electrical conductivity of the KNO3-Al2O3 composite was studied. Based on the analysis of DSC curves measured during heating and cooling of the sample, it was found that the enthalpy of phase transitions decreases with increasing time of mechanical activation of the 0.5KNO3-0.5Al2O3 composite. X-ray diffraction analysis shows that mechanical activation leads to a decrease in the grain dimension and an increase in the defectiveness. Based on the electrochemical impedance spectroscopy data, it was determined that for the KNO3-Al2O3 system subjected to mechanical activation, the values of specific ionic conductivity are 3.8×10-5 S/cm at T = 373 K and 2×10-3 S/cm at T = 473 K and the energy value activations of 0.19 eV are comparable with the parameters of a composite of the same chemical composition obtained by the ceramic technique. Raman spectroscopy revealed the formation of a metastable γ-phase KNO3during the mechanoactivation of the composite, which is stable at temperatures above 397 K. It is proposed that an increase in electrical conductivity in the KNO3-Al2O3 composite at 373-403 K is due to the presence in the composite of an additional metastable γ-phase KNO3.
THE INFLUENCE OF NANO-SIZED OXIDE FILLER ON THE STRUCTURE AND CONDUCTIVITY OF COMPOSITE (1–x) (LiClO4 –NaClO4) + xAl2O3
Authors: Kubataev Z. Yu. , Gafurov M. M. , Rabadanov K. Sh. , Amirov A. M. , Akhmedov M. A. , Kakagasanov M. G.
Published: April 2024

The physicochemical properties of the eutectic system 78.2LiClO4-21.8NaClO4 and its heterogeneous composites with nanosized aluminium oxide powder at various temperatures, phase states and concentrations of Al2O3 were studied by methods of Raman spectroscopy, differential scanning calorimetry (DSC) and impedance spectroscopy. The addition of Al2O3 leads to an increase in ionic conductivity and a decrease in activation energy. By the method of KRS spectroscopy it is shown that the addition of aluminum oxide leads to the formation of an amorphous phase due to the "destruction" of the crystalline phase of sodium perchlorate.
Analysis of Effect of Concentration Dependence of Exchange Current on the Metal Electrodeposition into Template Nanopores
Authors: Bograchev D. A. , Kabanova T. B. , Davydov A. D.
Published: April 2024

Metal electrodeposition into the nanopores of template of porous anodic alumina type under the conditions of mixed kinetics is studied theoretically using analytical and numerical methods. Two main stages of the process are studied: the non-steady-state formation of diffusion layer in the template pores and much longer process of pore filling with metal. The effect of nonlinearity of the concentration dependence of exchange current density of metal electrodeposition on the current density of the diffusion layer formation and pore filling with metal is studied.
ELECTROCHEMICAL PARAMETERS OF MICROBIAL FUEL CELLS BASED ON THE MICROCOCCUS LUTEUS STRAIN, NEW ION-EXCHANGE MEMBRANES AND VARIOUS SUGARS
Authors: Chesnokova A. N. , Zakarchevsky S. A. , Zhdanova G. O. , Stom D. I.
Published: April 2024

We studied the physicochemical and electrochemical characteristics of microbial fuel cells (MFCs) with a new proton-exchange membrane. It was synthesized on the basis of zeolite-doped polyvinyl alcohol cross-linked with sulfosuccinic acid (PVA-SSA-BEA). An MF-4SK industrial membrane (Plastpolymer, Russia) was used as a comparative sample. Various sugars were added as substrates (glucose, arabinose, galactose, xylose). The role of the bioagent was performed by the strain Micrococcus luteus 1-i. MFCs with PVA-SSA-BEA and MF-4SK membranes showed rather close electrochemical characteristics. A higher electricity output was performed with the addition of glucose, galactose, the lowest - with the use of xylose. The data obtained indicate that the proposed PVA-SSA-BEA membrane is promising for use as an alternative to proton-exchange membranes widely used in fuel cell technology.
FEATURES OF THE ELECTROCHEMICAL BEHAVIOR OF CHLOROPHENOXY SUBSTITUTED COBALT AND COPPER PHTHALOCYANINATES IN NON-AQUEOUS MEDIA
Authors: Kovanova M. A. , Tikhomirova T. V. , Sakhapov I. F. , Gafurov Z. N. , Yakhvarov D. G. , Vashurin A. S.
Published: April 2024

The electrochemical behavior of tetra-4-[4-(2,4,5-trichlorophenoxy)]phthalocyaninates of cobalt(II) (CoPc) and copper(II) (CuPc) in N,N-dimethylformamide 0.1 M nBu4NBF4 was studied by cyclic voltammetry. It has been experimentally established that both metal complexes are capable of irreversible reduction. In the reverse part of the CV curve for CoPc, an oxidation peak is observed, which is absent during anodic scanning, and corresponds to the cathodic reaction product. The metal complexes themselves do not oxidize under the conditions.
Diamond Compact Electrodes with Increased Electroactivity: Anodic Oxidation of Ethylenediaminetetraacetic Acid
Authors: Pleskov Yu. V. , Кrotova M. D. , Еkimov E. A.
Published: April 2024

The diamond electrodes-compacts with extreme high boron-doping level, added with platinum, were prepared at a pressure of 8―9 GPa and temperature ~2500 К from growth mixtures В–С, Pt–C, and Pt–C–B. They are highly electroactive in the reaction of ethylenediaminetetraacetic acid electrooxidation. The oxidation current is a linear function of the ethylenediaminetetraacetic acid concentration over the 0.001–0.05 g-equ/L range. This system can be basic to an electroanalytical method for the ethylenediaminetetraacetic acid determination.
ELECTROTRANSPOT CHARACTERISTICS OF POLYANILINE-MODIFIED CATION EXCHANGE MEMBRANES IN SOLUTIONS OF NICKEL AND CHROMIUM SULFATES AND SULFURIC ACID
Authors: Falina I. V. , Loza N. V. , Kononenko N. A. , Kutenko N. A.
Published: April 2024

The electrotranspot and structural characteristics of the MK-40 and MF-4SK sulfocationic membranes modified with polyaniline in an electrodialysis apparatus were studied in solutions of nickel and chromium sulfates and sulfuric acid. The decrease in the conductivity of membranes and the increase in their diffusion permeability in solutions of all electrolytes after modification with polyaniline were estimated. The key effect of the charge of the counterion on the electrical conductivity of the initial and modified membranes was confirmed, and an unusual effect of reducing the electrical conductivity of the MF-4SK/PANI membrane with an increase in the concentration of a solution containing multi-charged counter-ion was found. The information on the effect of multi-charged ions on the structure of a homogeneous and heterogeneous membranes, obtained by the method of standard contact porometry, is supplemented by the estimation of transport and structural parameters of microheterogeneous model. Based on the analysis of the parameters of current-voltage curves in solutions of nickel and chromium sulfates and sulfuric acid, the prospects of using the polyaniline-modified membranes in the processes of electrodialysis treatment of acid solutions containing multi-charged ions are evaluated.
ELECTROCATALYTIC SYNTHESIS OF p-AMINOPHENOL
USING Fe-Ag-COMPOSITES
Authors: Ivanova N. M. , Vissurkhanova Ya. A. , Soboleva E. A. , Muldakhmetov Z. M.
Published: April 2024

p-Aminophenol was prepared by electrocatalytic hydrogenation of p-nitrophenol using Ag + Fe + Fe3O4 (or Fe2O3) composites as catalysts formed during heat treatment and electrochemical reduction of silver ferrite, AgFeO2. AgFeO2 samples were synthesized by co-precipitation method without and in the presence of a polymer (polyvinyl alcohol, polyvinylpyrrolidone). The effect of the polymers on the phase constitutions of metal composites formed at the stage of synthesis, during the heat treatment and electrochemical reduction was established. The high electrocatalytic activity of prepared Fe-Ag-containing composites in electrohydrogenation of p-nitrophenol with an increase of hydrogenation rate by 2.2-2.7 times in comparison with its electrochemical reduction in similar conditions was shown.
UNIVERSAL ELECTROCATALYTIC SYSTEM FOR CONVERSION OF ALCOHOLS INTO CARBONYL COMPOUNDS AND CARBOXY ACID FUNCTIONAL DERIVATIVES
Authors: Kashparova V. P. , Shubina E. N. , Tokarev D. V. , Antropov G. P. , Zhukova I, Yu.
Published: April 2024

A universal catalytic system 4-acetamido-2,2,6,6-tetramethylpiperidine-1-oxyl/KI/pyridine base for the conversion of alcohols into carbonyl compounds and derivatives of carboxylic acids has been developed. The use of pyridine, 2,6-lutidine or collidine made it possible to obtain carbonyl compounds (yield up to 100%) after 2-2.2 F/mol. In the presence of pyridine, aliphatic alcohols are converted to esters (yield up to 35%) after 3-4 F/mol. Acid anhydrides (yield up to 80%) are formed using 2,6-lutidine or collidine after 5-6 F/mol. Nitriles were obtained in the presence of 2,6-lutidine and a source of nitrogen (yield up to 99%) after 3-4 F/mol.
ELECTROCHEMICAL REDUCTION OF CARBON DIOXIDE TO FORMATE IN ACID ELECTROLYTE IN ACETYLENE BLACK GAS DIFFUSION ELECTRODE WITH A LEAD CATALYST
Authors: Kolyagin G. A. , Taran O. P.
Published: April 2024

The possibility of electrosynthesis of formate from CO2 at a current density of 50–190 mA/cm2 in sulfuric acid aqueous solutions (pH 2–2.5) in a gas diffusion electrode with a lead electrocatalyst deposited on acetylene black was studied. It is shown that with an appropriate selection of the electrolyte composition, it is possible to carry out the electrosynthesis process with parameters that practically differ little from those in alkaline solutions. The highest current efficiency of 74% was obtained at a potential of -1.89 V, a current density of 150 mA/cm2 in an electrolyte of 0.5 M K2SO4 + 0.083 M H2SO4.
Oxidation of Formaldehyde on PdNi Nanowires Synthesized in Superfluid Helium
Authors: Manzhos R. A. , Kochergin V. K. , Krivenko A. G. , Khodos I. I. , Karabulin A. V. , Matyushenko V. I.
Published: April 2024

The possibility of using a boron-doped diamond electrode with a net structure of PdNi alloy nanowires deposited on its surface by laser ablation in superfluid helium as a formaldehyde sensor is considered. High sensitivity of such an electrode to trace amounts of formaldehyde was shown.
ELECTROCHEMICAL REDUCTION DOPING OF TiO2 NANOTUBES TO INCREASE THE EFFICIENCY OF PHOTOELECTROCHEMICAL WATER SPLITTING
Authors: Zos’ko N. A. , Kenova T. A. , Taran O. P. , Zhizhaev A. M.
Published: April 2024

TiO2 films being a 1D nanotube structure were obtained by electrochemical anodic oxidation of titanium foil. Electrochemical reduction activation of electrodes based on TiO2 nanotubes was carried out using the method of cyclic voltammetry (CV). The activated electrodes showed significantly higher current density and quantum efficiency of the photoelectrochemical water splitting compared to native TiO2 nanotubes. Electrochemical treatment of electrodes by the CV method leads to an increase in the photocurrent density from 4 to 14 times, depending on both the wavelength used and the applied potential. The analysis of electrochemical impedance spectra showed that the increase in the photoelectrochemical process performance is due to an increase in the charge transfer rate at the semiconductor/electrolyte interface, as well as improved electronic conductivity of the oxide layer, which contributes to better charge carrier separation and a decrease in their recombination rate.
ELECTROCHEMICAL BEHAVIOR OF DIMETHYLSULPHONE ON A PLATINUM ELECTRODE
Authors: Akhmedov M. A. , Khidirov Sh. Sh. , Suleymanov S. I.
Published: April 2024

In this work, we studied the effect of dimethylsulfone concentrations on the rate of anodic oxygen evolution and cathodic hydrogen evolution on a platinum electrode in acidic and alkaline media. By the method of calculating the DFT electron density functional at the level of the B97-3c theory using the Orca 4.2.0 program, the dimethyl sulfone bond breaking energy on the surface of platinum will be preferable through C-S bonds, according to the ion-radical mechanism. It has been confirmed by NMR and Raman spectroscopy that the end products of the anodic oxidation of dimethylsulfone in an acidic medium are methanesulfonic acid and dimethyldisulfone, in an alkaline medium - only dimethyldisulfone; the end products of cathodic reduction of DMSO2 are dimethylpolysulfides. Based on the obtained experimental results, a scheme of the electrocatalytic behavior of dimethylsulfone on a platinum electrode is proposed.
ELECTROSYNTHESIS OF CATALYTIC ACTIVE Pd-Cu AND Pd-Au BIMETALLIC NANOPARTICLES NANOCOMPOSITES WITH POLY(N-VINYLPYRROLIDONE) AND NANOCELLULOSE
Authors: Fazleeva R. R. , Nasretdinova G. R. , Evtyugin V. G. , Gubaidullin A. T. , Yanilkin V. V.
Published: April 2024

It was investigated the preparation in an undivided cell of Pd-Cu and Pd-Au bimetallic nanoparticles (NPs) by methylviologen (MV2+) -mediated electrochemical reduction of equimolar amounts of Cu(II), Pd(II) and Au(I) in the presence of poly(N-vinylpyrrolidone) (PVP) and nanocellulose (NC) at controlled potential of generating MV cation radical in aqueous medium at room temperature. Electrosyntheses were performed by sequential or joint reduction of metal ions by passing a theoretical amount of electricity. When Pd(II) ions are added to CuNPs, as well as Au(I) ions are added to PdNPs, a galvanic replacement process is observed, namely oxidation of Cu0 by Pd(II) and Pd0 Au(I) ions. The results of complete reduction are nanocomposites of mainly spherical MNPs, dispersed in the solution bulk, and stabilized by PVP on the surface of the NC. In the sequential synthesis of CuNPs and then PdNPs, the nanocomposite is presented as Cu2O nanoroses coated with fine PdNPs. Nanocomposites of Pd NPs with Cu2O or Au shows the mainly formation of spherical particles with the size of 4 to 50 nm depending on the production method. X-ray powder diffraction (XRD) data of nanocomposites confirm the formation of a mixture of PdNPs (0.8 - 10 nm) with large gold crystallites (until 24 nm), as well as the oxidation of CuNPs to cuprite (Cu2O). The size of metal crystallites and copper oxide varies in the range from 0.8 to 24 nm. In the test reaction of p-nitrophenol reduction with sodium borohydride in aqueous medium, all tested nanocomposites showed time-increasing catalytic activity. When Cu is added to Pd, the catalytic reduction reaction is maintained, while the addition of Au to Pd decreases the catalytic activity of PdNPs by an order of magnitude.
ELECTROCHEMICAL BEHAVIOR OF Er-DOPED LITHIUM TITANATE IN WIDE POTENTIAL RANGE
Authors: Kornev P. V. , Kulova T. L. , Kuz’mina A. A. , Skundin A. M. , Chirkova E. V. , Koshel’ E. S. , Klimova V. M.
Published: April 2024

The effect of lithium titanate doping by erbium on reversible lithium insertion in a widened potential range (3.00 to 0.01 V vs Li/Li+) was studied for the first time. Er-doped lithium titanate was manufactured with high-temperature solid-state synthesis. Er-doping (as doping with other lanthanides) was found to allow rather stable cycling in a wide potential range, discharge capacity being depended on the dopant content and is maximal at 2% Er. Upon discharge at 12 C the specific capacity amounted to 71 mAh/g, which is higher than that for other rare-earth dopants.
ELECTROCHEMICAL PHOSPHORYLATION OF TERMINAL ACETYLENES
Authors: Tarasov M. V. , Khrizanforova V. V. , Gryaznova T. V. , Budnikova Yu. G.
Published: April 2024

Electrocatalytic phosphorylation of terminal acetylenes with diarylphosphine oxides in the presence of a bpyCo(BF4)2 catalyst was first implemented under electro-reducing conditions with yields up to 75%. The nature of the solvent and the background electrolyte, the presence of oxygen and water determine the formation of certain products of phosphorylation of acetylenes. The variation of the above factors was carried out in order to select optimal conditions for electrosynthesis to achieve stereo and chemoselectivity. Voltammetric studies were used to establish the redox properties of participants to optimize processes involving a cobalt catalyst.
INFLUENCE OF THE METHOD OF FORMING A Pr2CuO4-BASED CATHODE ON THE ELECTROCHEMICAL CHARACTERISTICS OF
A PLANAR ELECTROLYTE-SUPPORTED SOFC
Authors: Dobrovolsky Yu. O. , Lyskov N. V. , Mazo G. N.
Published: April 2024

The influence of the method of organising the cathode microstructure based on Pr2CuO4 (PCO) on the electrochemical characteristics of a model electrolyte-supported solid oxide fuel cell (SOFC) has been investigated. It is shown that an increase in the thickness of the PCO cathode layer and the introduction of a pore-forming agent contribute to an increase in the power density of the SOFC test cell compared to a sample with an initial unmodified cathode structure, whose power density at 850°C was 34 mW/cm2. It was found that the optimum thickness of the cathode layer to achieve maximum electrochemical performance was in the range of 40-50 μm, while the power density achieved was 116 mW/cm2 at 850°C. At the same time, the transition from a single-phase PCO cathode to a composite of PCO-Ce0.9Gd0.1O1.95 (60/40 wt. %) provides an increase in power density up to 130 mW/cm2 at 850°C, while the dynamics of its decrease with reducing temperature is slower compared to the single-phase cathode. The analysis of the changes in the values of the total electrode polarisation resistance of the model SOFC, determined by impedance spectroscopy, as a function of the method of cathode formation, showed that during the transition from the initial sample to the samples with increased thickness of the cathode layer and the composite cathode, a twofold (in the first case) and threefold (in the second case) decrease in the level of polarisation losses is observed, which correlates with an increase in the power density. The proposed methods of modifying the initial cathode microstructure based on PCO show a positive dynamic of increasing the electrochemical activity of the cathode/electrolyte interface and the power density characteristics of the fuel cell as a whole.
COMPOSITE MATERIALS BASED ON THERMALLY EXPANDED GRAPHITE FOR BIPOLAR PLATES OF FUEL CELLS
Authors: Eroshenko V. D. , Andreeva V. E. , Tokarev D. V. , Medennikov O. A. , Klushin V. A. , Fesenko L. N. , Smirnova N. V.
Published: April 2024

Composite materials based on a thermosetting binder and thermally expanded graphite with a filler content of 50-70% were obtained by hot pressing. The influence of the method of introducing the filler into the composite on its physical, mechanical and electrochemical characteristics has been studied. Materials obtained by mixing air-dry components are characterized by high electrical conductivity (up to 195 S/cm) and strength properties (more than 25 MPa), low interfacial contact resistance (less than 10 mΩ cm2) and a corrosion current not exceeding 1 μA/cm2, which will allow ensure high efficiency of energy conversion in PEM FC.
THE INFLUENCE OF THE SYNHTETIC WAY OF LAYERED-TYPE MANGANSESE DIOXIDE ON THE PROPERTIES OF CATHODE MATERIALS FOR AQUEOUS ZINC-ION BATTERIES
Authors: Kamenskii M. A. , Popov A. Ju. , Eliseeva S. N. , Kondratiev V. V.
Published: April 2024

This research presents an analysis of physico-chemical, structural and electrochemical properties of cathode materials for aqueous zinc-ion batteries based on manganese dioxide with birnessite-type structure in dependence on the conditions of hydrothermal synthesis. The manganese oxides obtained are capable to the reversible zin ions intercalation into the crystal lattice because of large interlayer distances. They were considered two approaches of synthesis: a reaction between manganese sulfate and potassium permanganate at 160 °С (MnO2-I) and a hydrothermal treatment of potassium permanganate solution at 220 °С (MnO2-II). From the structural analysis it was shown that both methods allow obtaining the birnessite-type manganese dioxide. At the same time, electrochemical properties of cathodes obtained differ in the models of aqueous zinc-ion batteries. MnO2-II material demonstrate higher initial specific capacity (180 mAh∙g-1 at current density 0.3 A∙g-1) while its cyclic stability is on 40% lower than for MnO2-I material. This can be explained with higher surface area of the active material and lower crystallinity.
REACTIVITY OF ANION RADICAL AND DIANION OF ORGANIC COMPOUNDS (REVIEW)
Authors: Mendkovich A. S. , Rusakov A. I.
Published: April 2024

The results of experimental and theoretical studies of π*-anion radicals and π*-dianions reactions are analyzed. Particular attention is paid to their role in electrochemical reduction processes. By the example of three most typical reactions for these particles, the main factors determining their reactivity are considered.
TRANSPORT PROPERTIES OF La2(WO4)3-Al2O3 COMPOSITES
Authors: Pestereva N. N. , Guseva A. F. , Vasilenko N. A. , Beketov I. V. , Selezneva N. V.
Published: April 2024

Composites (1-φ)La2(WO4)3 – φAl2O3 (φ is the volume fraction of nanodispersed aluminum oxide) were obtained by the solid-phase method, their thermal properties, morphology, electrical conductivity depending on temperature, oxygen pressure in the gas phase, and composition were studied. It was found that the conductivity of composites (1-φ)La2(WO4)3 – φAl2O3 passes through a maximum at φ ~ 0.1 and reaches a value of 7 10-3 S/cm at 1000°C, which is 7 times higher than the conductivity of La2(WO4)3 at given temperature. Using the EMF method and measuring the dependence of electrical conductivity on oxygen pressure in the gas phase, the ionic nature of the conductivity of (1-φ)La2(WO4)3 – φAl2O3 composites was established.
STUDY OF ELECTROCHEMICAL SYNTHESIS FEATURES OF CNTS THIN FILMS ON TITANIUM AND TANTALUM FOIL SUBSTRATES
Authors: Rakitin V. V. , Feoktistova L. S. , Gapanovich M. V. , Stanchik A. V. , Sedlovets D. M.
Published: April 2024

The features of electrochemical deposition of copper layer on titanium and tantalum flexible substrates, as well as modes of sequential electrochemical deposition of tin layer on Cu/Ti and Cu/Ta and nickel layer on Sn/Cu/Ti and Sn/Cu/Ta from corresponding electrolyte solutions were studied by cyclic voltammetry. Deposition potentials for each metal layer were determined taking into account the type of substrate, and a wide set of the Cu-Sn-Ni/Ti and Cu-Sn-Ni/Ta stable precursor films were synthesized. The stage of annealing in an active sulfur atmosphere (sulfurization) has been optimized in order to obtain the Cu2NiSnS4 stable compounds. Based on the obtained XRD and Raman spectroscopy data, it was found that annealing in active sulfur atmosphere at 550 °C for 60 minutes is necessary to synthesize the Cu2NiSnS4 stable single-phase compounds with polycrystalline structure on Ta and Ti substrates
INFLUENCE OF THE POSITIVE ELECTRODE PROPERTIES ON THE ACTIVATION TIME OF THE RESERVE CHEMICAL POWER SOURCES OF THE SYSTEM LEAD – PERCHLORIC ACID – LEAD DIOXIDE
Authors: Shcheglov P. A. , Samsonov D. A. , Pavlenkov A. B. , Kulova T. L. , Rychagov A. Yu. , Nikolskaya N. F. , Shiryaev A. A. , Skundin A. M.
Published: April 2024

The influence of the positive electrode properties on the activation time of the reserve chemical power sources of the system lead – perchloric acid – lead dioxide has been studied. Coatings of cathodes with lead dioxide obtained under various conditions are characterized by scanning electron spectroscopy, X-ray spectral microanalysis, X-ray photoelectron spectroscopy, standard contact porosimetry. The improvement of the performance characteristics of power sources including the ensuring of a short time of their activation at a low temperature has been shown to be possible with the use of a nanoporous coating of lead dioxide. To estimate the applicability of cathodes for the manufacture of power sources having minimal activation time a diagnostic principle has been used that it based on testing of cathodes by the method of chronopotentiometric measurements during galvanostatic discharge. Pilot industrial samples of small-sized reserve power sources of the mentioned electrochemical system with unprecedented short activation time (less than 30 ms at temperarure –50°С) were manufactured and tested.
LiAsF6 SOLUTIONS IN THE MIXED SOLVENTS OF PROPYLENE CARBONATE – DIMETHYL SULFOXIDE: ELECTRIC CONDUCTIVITY AND ELECTROCHEMICAL STABILITY
Authors: Tyunina E. Yu. , Chekunova M. D.
Published: April 2024

The specific conductivities of LiAsF6 solutions in a mixed solvent of propylene carbonate (PC) –dimethyl sulfoxide (DMSO) were measured at temperatures of 253.15, 263.15, 273.15, 283.15, 293.15, 303.15, 313.15, 323.15 and 333.15 K being a ionophore concentration of 0.2 to 1.4 mol / kg. The portion of DMSO in the mixed solvent was varied in the range of (0.2 - 0.75) mole fractions. The specific conductivities of LiAsF6 in DMSO were studied in the temperature range of (293.15 – 333.15) K. Concentration dependences of specific conductivity of the system can be described by the Casteel-Amis equation. The contributions of the solvent and ionophore to the activation energy of the ionic conduction process are determined on the base of the transition state theory. It has been found that the LiAsF6 solutions in a mixed PC – DMSO solvent have a narrower electrochemical window compared to the solutions of this ionophore in pure PC and DMSO solvents.
SYNTHESIS AND PPOPERTIES OF ZNO/ZNWO4 NANOCOMPOSITES FOR PHOTOELECTROCHEMICAL APPLICATIONS:
Authors: Ulyankina A. A. , Tsarenko A. D. , Molodtsova T. A. , Gorshenkov M. V. , Smirnova N. V.
Published: April 2024

A series of ZnO/ZnWO4 nanocomposites with different ZnWO4 content based on ZnO and WO3 nanopowders electrochemically synthesized under pulse alternating current was obtained. A complex of physicochemical methods (X-ray diffraction, Raman spectroscopy, transmission electron microscopy, energy dispersive X-ray microanalysis) was used to study the composition and structural characteristics of the obtained materials. The nanocomposite with optimal composition (ZnO 90%, ZnWO4 ~6%) was used as a photoanode material for a flow photocatalytic fuel cell with sulfate electrolyte with the addition of organic and inorganic fuel. The maximum values of Eoc and Pmax, which were 850 mV and 85.8 μW/cm2, respectively, were achieved using Na2SO4 with the addition of glucose as a fuel.
Calculation of the Electric Field Strength and Current Density Inside a Thin Metal Layer, Taking into Account the Skin Effect
Authors: Zavitaev E. V. , Rusakov O. V. , Chukhleb E. P.
Published: April 2024

For the first time, the problem of the distribution of the electric field and electric current inside a thin metal layer in the presence of the skin effect is solved, taking into account the mirror-diffuse nature of the reflection of electrons from the inner surfaces of the layer. Limiting cases are considered and the results obtained are discussed.
PROBE AND SPECTRAL DIAGNOSTICS OF PLASMA GAS ENVIRONMENT: BCl3-Cl2
Authors: Murin D. B. , Chesnokov I. A. , Gogulev I. A. , Grishkov A. E.
Published: April 2024

Probe and spectral measurements of the plasma of the gaseous medium BCl3-Cl2 were carried out. Data were obtained on the influence of the initial composition of the gaseous medium on the electric field strength, gas temperature, particle concentration, reduced electric field strength under conditions of a direct current glow discharge. The emission spectra of the plasma of the gaseous medium BCl3-Cl2 were analyzed, the main emitting components were identified, and the relationships between radiation intensities and particle concentrations were established.
SEM Measurements of the Dimensions of Relief Structures in the Technological Process of Manufacturing Microcircuits
Authors: Novikov Yu. A. , Filippov M. N.
Published: April 2024

The problems of measuring the dimensions of relief elements on a scanning electron microscope (SEM) in the technological process of manufacturing microcircuits are considered. The first problem is related to the fact that the increase in the SEM during operation can vary over a wide range depending on the measured dimensions. The second problem is that the probe diameter determined in the SEM calibration process differs from the diameter used in operational measurements. The third problem is related to the fact that it is not known which relief parameter is measured in the SEM probe defocusing method. It is shown that to solve the first problem, it is necessary to calibrate the mark on the image using structures with a trapezoidal profile and large angles of inclination of the side walls. The solution of the second problem is based on the method of defocusing the SEM probe: determining the dependence of the sizes between certain points on the SEM signals on the probe diameter and extrapolating this dependence to the zero value of the diameter. The third problem is solved with the help of a virtual scanning electron microscope.
Simulation of the Adsorption and Diffusion of Lithium Atoms on Defective Graphene for a Li-Ion Battery
Authors: Asadov M. M. , Mammadova S. O. , Huseynova S. S. , Mustafaeva S. N. , Lukichev V. F.
Published: April 2024

Based on the density functional theory (DFT) with allowance for spin polarization or the local spin density approximation (LSDA), we calculate the adsorption and diffusion properties of a lithium atom on a graphene ( ) monolayer with monovacancy ( ) as the anode material for an -ion battery. The DFT LSDA calculations are performed in relaxed 5 × 5 and 6 × 6 supercells and based on graphene with the monovacancy + lithium adatom complex . Based on the calculated values of the adsorption energy of the lithium atom , the energetically stable location of the lithium adatom is determined on a monolayer of supercells in and . The calculation results show that the adatom energetically prefers to be adsorbed in the pit position (H-site) rather than adsorbed from above (T-site) of the carbon atom in the monolayer. The DFT LSDA calculated electronic band structure and local total and partial magnetic moment of supercell atoms are consistent with the calculations performed by the generalized gradient approximation (GGA)-PBE functional for the H-, B-, and T-sites of graphene. Taking into account the experimentally obtained diffusion coefficients of lithium in two-layer graphene in the struc-tural packing of an AB package and the temperature (263–333 K) dependence of Li diffusion in two-layer graphene, which is described by the Arrhenius law, the diffusion activation energy of is calculated at con-centrations of = 0.06–0.51 in LixC12 graphene in the AB packaging.
Surface Morphology and Photoluminescence Spectra of Pseudomorphic {InGaAs/GaAs} Superlattices on GaAs (100), (110), and (111)A Substrates
Authors: Klimov E. A. , Pushkarev S. S. , Klochkov A. N. , Mozhaeva M. O.
Published: April 2024

The production of superlattices with pseudomorphically strained quantum wells (QWs) {InxGa1–xAs/GaAs} grown by molecular beam epitaxy on GaAs substrates with (100), (110), and (111)A crys-tallographic surface orientations is reported. The quality of the crystal structure of epitaxial samples is assessed using the atomic force microscopy of their surface. The manifestation of a piezoelectric field in the photoluminescence spectra is reported.
Hydrogen Plasma under Conditions of Electron-Cyclotron Resonance in Microelectronics Technology
Authors: Polushkin E. A. , Nefed’ev S. V. , Koval’chuk A. V. , Soltanovich O. A. , Shapoval S. Yu.
Published: April 2024

This paper presents the results of hydrogen electron-cyclotron resonance (ECR) plasma in micro-electronics technology. Its effect on the radiation resistance of the IC and on the quality of the ohmic contact during the formation of UBM metallization is demonstrated. The devices obtained with the use of plasma ECR and without it are analyzed.
Simulation of a System of Nanoantennas Located in a TSV Channel as a System for Receiving and Transmitting Data
Authors: Serov D. A. , Khorin I. A.
Published: April 2024

The results of a theoretical study of the behavior of a system of nanophotonic devices, consisting of receiving and transmitting plasmonic metal antennas, are presented. Based on the finite element method, the main parameters of antennas located in the TSV channel and receiving a signal in the terahertz frequency range are calculated. The limiting range of signal transmission and the coefficient of its amplification are determined. Conclusions are drawn on the suitability of the presented configuration as a system for wireless data transmission and reception in three-dimensional integrated circuits.
Design of a Nonlinear Model of a Pseudomorphic 0.15 μm рHEMT AlGaAs/InGaAs/GaAs Transistor
Authors: Tsunvaza D. , Ryzhuk R. V. , Vasil’evskii I. S. , Kargin N. I. , Klokov V. A.
Published: April 2024

This paper studies the design of a nonlinear model of AlGaAs/InGaAs/GaAs рHEMT micro-wave-frequency range transistors with a gate length of 0.15 μm using parametric analysis methods. In the cal-culations, not only nonlinear current sources but also the dependences of the nonlinear gate-source and gate-drain capacitances on voltages are studied. It is shown that the proposed model makes it possible to describe the IV characteristics of the studied device adequately in the range of drain currents from 0 to 100 mA and the frequency range from 5 to 45 GHz. The error of the model does not exceed 3%
Tomography of Detectors Taking Dead Time into Account
Authors: Bogdanov Yu. I. , Katamadze K. G. , Borshchevskaya N. A. , Avosopiants G. V. , Bogdanova N. A. , Kulik S. P. , Lukichev V. F.
Published: April 2024

Using numerical simulation methods that take into account the dead time effect, algorithms are developed to calculate the detector’s response for photon fluxes with different photon number distributions, including the Poisson, Fock, and thermal distributions. Based on the results obtained, a detector tomography method is developed, as well as an algorithm for identifying the corresponding elements of a positive opera-tor-valued measure (POVM). Experimental studies using coherent states demonstrate close agreement between the calculation results and experimental data.
Study of the Sensor Properties of Ordered ZnO Nanorod Arrays for the Detection of UV Radiation
Authors: Evstafieva M. V. , Knyazev M. A. , Korepanov V. I. , Red’kin A. N. , Roschupkin D. V. , Yakimov E. E.
Published: April 2024

Zinc oxide is one of the most promising materials used to create devices in the ultraviolet (UV) range. In this article, we study the sensor properties of ordered ZnO nanorod arrays grown by chemical vapor deposition. The possibility of their use as an indicator of UV radiation to control the dose of UV radiation, both from natural and artificial light sources, is assessed. The X-ray diffraction, Raman spectroscopy (RS), and cathodoluminescence (CL) data demonstrate the high quality of nanorods. Based on the ZnO nanorod array, a sensor prototype was fabricated based on the change in ZnO conductivity under the UV irradiation. A compari-son of the response of such a sensor with the readings of a UV radiometer showed a high correlation.
Influence of Structural Defects on the Electrophysical Parameters of pin-Photodiodes
Authors: Koval’chuk N. S. , Lastovskii S. B. , Odzhaev V. B. , Petlitskii A. N. , Prosolovich V. S. , Shestovsky D. V. , Yavid V. Yu. , Yankovskii Yu. N.
Published: April 2024

The results of studies of electrophysical parameters of pin-silicon-based photodiodes, depending on their operating modes (external bias and temperature), manufactured on single-crystal silicon wafers of p-type conduction orientation (100) with ρ = 1000 ohm cm, are presented. The p+-type region (isotype junction) is created by the implantation of boron ions; the n+-type region, by the diffusion of phosphorus from the gas phase. It is established that on the voltage-current characteristics under reverse bias, three regions of dark cur-rent variation depending on the applied voltage can be distinguished, sublinear, superlinear, and linear, caused by various mechanisms of the generation-recombination processes in the depletion region of the pn-junction. A noticeable dependence of the barrier capacitance value (at a frequency of 1 kHz) and the size of the depletion region on temperature is observed only when the applied reverse voltages do not exceed the contact potential difference (V ≤ 1 V).