Кафедра "Фізика" ДІІТ (з 2022 року увійшла до складу кафедри Гідравлика, водопостачання та фізика)

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ENG: Department "Physics" DIIT (since 2022, the year has reached the warehouse of the Department of Hydraulics, water supply and physics)

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Accurate Calculations of Dynamic First Hyperpolarizability: Construction of Physically Justified Slater-Type Basis Sets
(John Wiley and Sons Inc., 2014) Rossikhin, V.; Voronkov, Eugene O.; Okovytyy, Sergiy I.; Sergeieva, T.; Kapusta, K.; Leszczynski, Jerzy; Voronkov, Yevgeniy O.
EN: An efficient procedure for construction of physically rationalized Slater-type basis sets for calculations of dynamic hyperpolarizability is proposed. Their performance is evaluated for the DFT level calculations for model molecules, carried out with a series of functionals. Advantages of new basis sets over standard d-aug-cc-pVTZ and recently developed LPOL-(FL,FS) Gaussian-type basis sets are discussed. © 2014 Wiley Periodicals, Inc.
Accurate Calculations of Second-Order Electric and Magnetic Properties: Two Ways of Physically Justified Modifications of Basis Sets
(Elsevier B.V., 2010) Bolshakov, V.; Rossikhin, V. V.; Voronkov, Eugene O.; Voronkov, Yevgeniy O.; Okovytyy, Sergiy I.; Leszczynski, Jerzy
EN: Second-order electric and magnetic properties calculated using an approach based upon the simultaneous analytical dependence of the bond order matrix and basis set functions on the corresponding perturbation parameters have been obtained and analyzed for a series of organic molecules. Various methods of selection of basis set quality for different atoms in investigated molecules were examined in conjunction with calculations of 1H NMR chemical shifts. Comparison of the results obtained at different levels of theory (HF, DFT, MP2) demonstrates small correlation effects for polarizability and magnetic susceptibility while the electron correlation effects play crucial role for calculations of nuclear magnetic shielding (chemical shifts).
Adhesion Strength of Electrodeposited Ni, Zn, and Fe Coatings with Copper Substrates
(Taylor & Francis Online, 2022) Shtapenko, Eduard Ph.; Zabludovsky, Vladimir A.; Tytarenko, Valentyna V.
ENG: This paper presents the adhesive strength values of electrodeposited nickel, zinc, and iron coatings on copper substrates at various deposition parameters, including laser-assisted stimulation of the deposition process. One of the factors determined to be responsible for the adhesive strength of metal films with a metal substrate is the formation of a diffusion zone at the ‘coating-substrate’ interface. It is shown that an increase in adhesive strength is achieved due to the expansion of the diffusion zone and the formation of solid solutions. The decrease in adhesive strength at high overpotentials is associated with the release of hydrogen and the formation of intermediate phases.
Adsorption of Co, Ni, Cu, Zn Metal Ions on Fullerene C60 and on Single-Wall Carbon Nanotubes C48 as a Driven Force of Composite Coatings’ Electrodeposition
(Oles Honchar Dnipro National University, 2021) Tytarenko, Valentina V.; Shtapenko, Eduard Ph.; Voronkov, Eugene O.; Vangara, Aruna; Zabludovsky, Vladimir A.; Kolodziejczyk, Wojciech; Kapusta, Karina; Okovytyy, Sergiy I.
EN: Composite electrodeposited films fabricated from aqueous solution of electrolytes that contain ions of metals along with carbon nanomaterial particles such as fullerene C60 were investigated. Results for the cathodic polarization curve showed an increase in charge-transfer resistance. Phase composition analysis for metal films revealed the presence of carbon nanoparticles (CNPs) inside the metal matrix and significant changes in the crystal lattice. As it shown on microphotographies, addition of CNPs changes columnar growth patterns of metallic films to microlayered structure due to passivation of the surface. Density Functional Theory was used for calculation of thermochemical, electronic and structural properties of metal ions complexes with CNPs. Calculated binding energies of the CNPs-Me2+ complexes suggests that an adsorption of Co2+, Ni2+, Cu2+, and Zn2+ ions on the surface of fullerene C60 and SWNT C48 is possible and thermodynamically favorable. Binding affinity was found to be significantly stronger when the metal ion was adsorbed onto a surface of SWNT C48, than adsorption to the fullerene C60. With Cu2+ complexes being the most thermodynamically stable, binding affinities were increasing in a row Co2+
Application of Pulse Current for Producing a Strengthening Composite Nickel Coating
(Eugen G. Leuze Verlag, 2019) Tytarenko, Valentyna V.; Zabludovsky, Vladimir A.; Shtapenko, Eduard Ph. ; Tytarenko, Igor V.
ENG: Carbon-containing nickel coatings deposited with use of pulse current from aqueous electrolyte solution comprising ultradispersed diamond particles were studied. Effect of pulse current on concentration and distribution of co-deposited nanodiamond particles through a metal substrate matrix, structure, mechanical and resistance properties of composite electrolytic coatings was analyzed. It was demonstrated that application of new generation additives, more specifically nanocarbon ones, provides opportunity for improving physicochemical properties of coatings. During pulse mode of deposition fine-grained coatings are formed with microlayer growth structure in cross section that enhance their microhardness, wear strength and corrosion resistance.
Calculation of Energy and Magnetic Susceptibility of Fe Atomic System During Dislocation Motion in Magnetic Field
(Emerald Group Publishing Ltd, United Kingdom, 2021) Kraiev, Maksym; Voronkov, Eugene O.; Kraieva, Violeta
ENG: Purpose – The purpose is to calculate the change in the total energy of a small fragment of an idealized lattice of iron (in its pure form and with impurity atoms) containing an edge dislocation during its elementary motion at one interatomic spacing, both under the influence of a constant magnetic field and without it. The introduction of a magnetic field into the system is aimed at checking the adequacy of the description of the phenomenon of magnetoplasticity by changing the total energy of the atomic system. Design/methodology/approach – The design procedure is based on a quantum-mechanical description of the switching process of the covalent bond of atoms in the dislocation core. The authors used the method of density functional theory in the Kohn-Shem version, implemented in the GAUSSIAN 09 software package. Using the perturbation theory, the authors modeled the impact of an external constant magnetic field on the energy of a system of lattice atoms. Findings – The simulation results confirmed the effect of an external constant magnetic field on the switching energy of the covalent bond of atoms in the dislocation core, and also a change in the magnetic susceptibility of a system of atoms with a dislocation. This complements the description of the magnetoplastic effect during the deformation of metals. Originality/value – The authors created quantum-mechanical models of the dislocation motion in the Fe crystal lattice: without impurities, with a substitutional atom Cr and with an interstitial atom C. The models take into account the influence of an external constant magnetic field.
Composition Variations and UV Irradiation Effect on Charge Transfer in PbMoO4 Single Crystals
(Oles Honchar Dnipro National University, 2022) Bochkova, Tatiana; Trubitsyn, Mykhailo P.; Volnianskii, M. D.; Volnyanskii, Dmytro M.
ENG: The effect of nonstoichiometry of the composition, PbO polymorphism, and preliminary irradiation with ultraviolet light on electrical conductivity of alternating current (AC) was studied in PbMoO4 crystals. The crystals were grown by Czochralski method in a direction deviated by 30° from a-axis in (001) plain. The charge was prepared from MoO3 and PbO, lead oxide was used of α- or β- structural modifications. The reagents were taken both in a stoichiometric ratio and with an excess of 0.5 mol % of MoO3. It was shown that the magnitude of the dark and irradiation-induced AC conductivity was affected both by the type of polymorphic form of PbO and by the excess amount of MoO3. The influence of the PbMoO4 crystal structural disorder on charge transfer processes are discussed within the framework of the model of hopping conduction in disordered media.
Determination of Activation Energy of Surface Diffusion Based on Thermal Oscillations of Atoms
(Прикарпатський національний університет імені Василя Стефаника, 2021) Syrovatko, Yuliya V.; Shtapenko, Eduard Ph.
ENG: This paper covers calculations of the activation energy of surface diffusion of ad-atoms on the substrate surface from the point of view of thermal oscillations of substrate atoms and ad-atoms. The main characteristic of oscillations of atoms and geometric mean frequency was calculated based on statistical approximation of the Debye model using the reference values of entropy and heat capacity of metals. The basic principle of the model of activation energy calculation presented in the paper is the formation of potential wells and barriers during oscillations of atoms localized in the sites of the lattice. Oscillations of atoms were considered in the framework of quasiclassical quantum approximation as the oscillations of harmonic oscillators in the potential parabolic wells. Dimensions of the negative part of values of the potential well energy were determined by the amplitude of thermal oscillations of atoms. Positive values constituted a significant part of the potential well energy values. Barriers were formed owing to interaction of positive values of the energy of parabolic wells of adjacent atoms. Therefore, in order to make the ad-atom jump, it is necessary to get out of the potential well having the negative values, and to overcome the potential barrier. The energy required for the ad-atom jump on the substrate surface was the activation energy of surface diffusion. The results obtained in this paper agree satisfactorily with the results of another method, which is based on determining the energy of ad-atom binding with the substrate atoms.
Development of a New Suspension Electrolyte based on Methanesulphonic Acid for the Electrodeposition of Cu–Tio2 Composites
(РС Тесhnology Сеntеr, Kharkiv, Ukraine, 2021) Sknar, Irina; Sknar, Yuri; Hrydnieva, Tatyana; Riabik, Pavel; Demchyshyna, Oksana; Gerasimenko, Dmitriy
EN: Electrodeposition of composite coatings based on copper is a promising direction in the creation of advanced materials for multifunctional purposes. An important area of composites application is to use them in the treatment systems for gas emissions and wastewater. It is advisable to use semiconductor oxide materials, in particular titanium dioxide, as the photocatalysts in the photo destruction of organic pollutants of wastewater. The structural features of wastewater treatment equipment require that titanium dioxide particles should be fixed in a rigid matrix. Resolving the task of fixing photosensitive elements at the surface of a certain configuration implies the electrodeposition of coatings by composites, in particular Cu–TiO2. An important factor affecting the functional characteristics of composites and their manufacturing technology is the nature of the electrolyte. It has been shown that the electrodeposition of Cu–TiO2 composites from methane-sulfonate electrolytes makes it possible to reduce the coagulation of the dispersed phase and to obtain coatings with a high content of titanium dioxide from a suspension solution containing no more than 4 g/l of TiO2. It was established that the content of the dispersed phase in the composite made at a current density of 2 A/dm2 and the concentration of titanium dioxide in the electrolyte at the level of 4 g/l is 1.3 % by weight, which is twice as much as when using a sulfate electrolyte. It has been shown that the increase in the content of the dispersed phase in the coatings from 0.1 to 1.3 % by weight is accompanied by an increase in the degree of photo destruction of the colorant from 6 to 15.5 %. The micro-hardness of coatings increases, in this case, by 30 %. The proposed electrolyte to make the Cu–TiO2 composites is an important contribution to the development of the synthesis of wear-resistant high-performance photocatalysts for treating wastewater from organic pollutants.
Dielectric Properties of the Pb2MoO5 Crystals Irradiated with uv Light
(Дніпровський національний університет імені Олеся Гончара, 2017) Volnyanskaya, I. P.; Trubitsyn, Mykhailo P.; Volnyanskii, Dmytro M.; Bondar, D. S.; Shvets, T. V.
EN: The dielectric properties of the Pb2MoO5 crystals, exposed to UV light radiation (290 K), were studied. It was shown that UV irradiation led to appearance of permittivity maximum near 530 K (AC field frequency f=1 kHz). Heating up to 700 K resulted in thermal dissociation of the dipole complexes, induced by UV light irradiation and contributing to e peak. The magnitude of the e maximum increased with increasing time of UV light exposure and saturated for t>90 min. It is supposed that the observed anomaly of e is determined by dielectric response of (MoO3)- complexes. These centers arise when photoelectrons are trapped by molybdenum ions with oxygen vacancy VO in the nearest surroundings.
Diffusion at the Film-Substrate Interface During Nickel Electrocrystallization on a Copper Substrate
(ФГУП "Наука", Москва, 2018) Shtapenko, Eduard F.; Zabludovsky, Vladimir A.; Tytarenko, Valentina V.
EN: The results of experimental studies of the diffusion layer at the interface between a nickel electrolyte film and a copper substrate are presented. Studies have shown that in the transition layer, diffusion of the deposited metal into the substrate material occurs. The depth of the diffusion layer and, consequently, the concentration of interstitial nickel atoms strongly depend on the electrocrystallization conditions: 2 μm in the constant-current mode and 4 μm under laser-assisted deposition. The diffusion coefficient of nickel adatoms in polycrystalline copper is 8.3 × 10–16 m2/s in the constant-current deposition mode and 3.3 × 10–13 m2/s under laser-assisted deposition.
Effect of Lattice Disorder on Charge Transfer in Lead Molybdate Crystals
(Oles Honchar Dnipro National University, Ukraine, 2023) Bochkova, Tatiana; Krivchenko, A. Yu.; Trubitsyn, M. P.; Volnianskii, M. D.; Volnyanskii, Dmytro M.
ENG: Electrical properties of PbMoO4 crystals, grown from the stoichiometric charge and non- stoichiometric charge with an excess of MoO3, are studied and compared in this work. The crystals are grown by Czochralski method in the direction at an angle of 30° to [100] axis in (001) plane. The single crystals are free from gas bubbles, cracks and have a weak yellowish color. It is found that the addition of MoO3 excess (0.5 mol.%) to the stoichiometric charge notably increases the crystal lattice disorder. It is assumed that the appearance of lead ion vacancies plays the main role in the structural disordering. An increase of conductivity in DC and AC field, changes of current-voltage characteristics and AC- conductivity spectra are interpreted based on the model of hopping conductivity in disordered systems.
Investigation of the Operation of the Railway Track with Reinforced Concrete Sleepers in Curved Sections with Radius R ≤ 350 m
(Printing House “Technologija”, Kaunas, Lithuania, 2020) Markul, Ruslan V.; Hubar, Oleksіy V.; Arbuzov, Maxim; Andrieiev, Volodymyr S.; Tiutkin, Oleksii L.; Savyts’kyy, V.; Ganich, Ruslan Ph.
ENG: The article presents the results of the research on polygon extension for laying reinforced concrete sleepers under difficult conditions (R≤350 m, mountainous terrain) with ensuring safety traffic and reliable operation of the railway track. Changes in the geometry of the track in the plane with wooden sleepers and Д0 fastener as well as reinforced concrete sleepers with СКД65-Б fastener in the curve with the radius of 350 m were investigated. The results of the research allowed to obtain: - method and algorithm for determining the tapping section of the track gauge extension on reinforced concrete sleepers in curves with radius R ≤ 350 m; - comparative assessment of the track gauge change with the use of Д0 fastener (wooden sleepers) and СКД65-Б fastener (reinforced concrete sleepers) in curves with a radius R ≤ 350 m; - factors impact on the track gauge extension under difficult operating conditions; - empirical dependence of the process of the track gauge width change and the frequency of its adjustment in the cases of СКД65-Б fastener (reinforced concrete sleepers) and Д0 fastener (wooden sleepers) use in curves with radius R ≤ 350 m; - conclusions on the probability and feasibility of concrete sleepers use under mountainous terrain conditions, including difficult operating conditions (R ≤ 350 m).
Kinetic Regularities of the Formation of Composite Electrolytic Coatings Containing Ultradispersed Diamond Particles
(Vasyl Stefanyk Precarpathian National University, Ukraine, 2022) Tytarenko, Valentyna V.; Zabludovsky, Vladimir A.; Shtapenko, Eduard Ph.; Tytarenko, Igor V.
ENG: The paper formulates the problem of joint electrolytic co-deposition of metal ions and ultradispersed diamond particles into a metal matrix. It presents the developed mathematical model that describes the mechanism and kinetics of the cathode process, mass transfer of metal ions and ultradispersed diamond particles. A satisfactory correlation with experimental data was obtained. The contribution of the thermal action of laser radiation to the intensification of the process of co-deposition of dispersed particles and metal ions was determined. It was found that the more intense penetration of dispersed phase particles into the forming coating during the laser stimulation of the electrodeposition process is due to the presence of a temperature gradient, which provides an additional supply of metal ions in the irradiation region. Based on the theoretical and experimental studies, we established the regularities of the influence of the number and size of nanoparticles on the strengthening properties of composite metal coatings. It was found that an increase in the temperature of an aqueous electrolyte solution in the cathode region during a laser-stimulated deposition process leads to an increase in the flux density of ultradispersed diamond particles, and, as a result, to an increase in the concentration of the dispersed phase in nickel composite coatings, which contributes to the formation of a finer crystalline structure of coatings, an improvement in adhesion, strength properties and increased wear resistance of coatings.
Laser-Enhanced Electrodeposition of Nickel Coatings
(Taylor & Francis Group, London, 2017) Zabludovsky, Vladimir A.; Tytarenko, Valentyna V.; Shtapenko, Eduard Ph.
ENG: A method for producing the composite nickel coatings with a programmable pulse current with the changing from one layer to the concentration of particles in the metallic matrix of nanodiamonds. It is shown that this program allows layer-coating with the lowest concentration of nanodiamond in the first coating layers and increasing in subsequent layers, which improves adhesive properties, increases wear resistance and lowers the cost of dispersed particles of nanodiamond.
Logarithmic Wave-Mechanical Effects in Polycrystalline Metals: Theory and Experiment
(Springer-Verlag, 2021) Kraiev, Maksym; Domina, Kateryna; Kraieva, Violeta; Zloshchastiev, Konstantin G.
EN: Schro¨dinger-type wave equations with logarithmic nonlinearity occur in hydrodynamic models of Kortewegtype materials with capillarity and surface tension, which can undergo liquid–solid or liquid–gas phase transitions. One of the predictions of the theory is a periodic pattern of density inhomogeneities occurring in the form of either bubbles (topological phase), or cells (non-topological phase). Such inhomogeneities are described by solitonic solutions of a logarithmic wave equation, gaussons and kinks, in the vicinity of the liquid–solid phase transition. During the solidification process, these inhomogeneities become centers of nucleation, thus shaping the polycrystalline structure of the metal grains. The theory predicts a Gaussian profile of material density inside such a cell, which should manifest in a Gaussian-like profile of microhardness inside a grain. We report experimental evidence of large-scale periodicity in the structure of grains in the ferrite steel S235/A570, copper C-Cu/C14200, austenite in steel X10CrNiTi18-10/AISI 321, and aluminum–magnesium alloy 5083/5056; and also Gaussian-like profiles of microhardness inside an averaged grain in these materials.
Model of Dispersed Phase Particle Distribution in a Composite Electrolytic Coating
(Springer Science + Business Media, США, 2020) Tytarenko, Valentina V.; Zabludovsky, Vladimir A.; Shtapenko, Eduard Ph.
EN: A model is proposed to evaluate distribution of dispersed phase particles in a composite metal coating. This model is based on calculation of degree of surface occupation by particles and their distribution in volume. Effective parameters applied for electrolytic composites evaluation at the microscale level were formulated, and method for the parameters evaluation was set out. It was shown that density of distribution and portion of particles with certain size in a coating depend on electrodeposition modes. Generation of higher-fine crystalline close-packed structures of coatings in conditions of pulse relative duration increase from 2 to 50 and unchanged current frequency 50 Hz is caused by both increase of oversaturation at the crystallization front that results in higher non-equilibrium process of crystallization and also by passivation effect of UDD particles on the surface which is formed. Non-equilibrium conditions of crystallization give rise to more intensive penetration of disperse phase particles with smaller size (~ 0.25–1 μm) into growing coating, decrease of microlayers thickness from 4 to 2 μm and increase of UDD particles concentration from 1.43 to 2.47 mas.%.
Multi-Component Nitrated Ion-Plasma Ni-Cr Coating
(Oles Honchar Dnipro National University, Dnipro, 2021) Nadtoka, V.; Kraiev, Maksym; Borisenko, A.; Kraieva, Violeta
ENG: Method for ion-plasma deposition is applied for covering of heat-resistant Ni-Cr alloy XH78T. Coating deposition is performed under nitrogen gas atmosphere at the pressure from 3×10-5 to 1×10-2 Torr. The nitrogen content in the coating is reached up to 2,7 %. Nitrated coatings with a thickness of 184-222 μm is obtained without embrittlement and with a uniform distribution of microhardness. The effect of the nitrogen pressure in a vacuum chamber on the structure of the coatings, which changes from homogeneous to columnar with conical crystallites, is presented. Nitration increases microhardness of the coatings from 3669 to 7575 HV, the wear resistance of the coatings increases by 6-8 times. The received coatings can be used to increase the durability of metallurgical equipment parts.
Novel Physically Adapted STO##-3G Basis Sets. Efficiency for Prediction of Second-Order Electric and Magnetic Properties of Aromatic Hydrocarbons
(John Wiley & Sons, Inc., 2012) Voronkov, Eugene O.; Voronkov, Yevgeniy O.; Rossikhin, V. V.; Okovytyy, Sergiy I.; Shatckih, A.; Bolshakov, V.; Leszczynski, Jerzy
EN: Efficient scheme for construction of physically justified STO##-3Gel and STO##-3Gmag basis sets has been proposed. It is based upon the analysis of analytical form of the first-order correction functions to unperturbed STO basis sets under the perturbation by electric or magnetic fields. The test calculations of polarizability, magnetic susceptibility and chemical shifts performed for a series of aromatic compounds within the developed basis set in the framework of Hartree-Fock and Density Functional Theory (DFT) approaches show good agreement of the predicted properties with experiments.
Phase Composition of Galvanic Iron-Nickel Alloys Obtained Using Pulsed Current
(Vasyl Stefanyk Precarpathian National University, 2021) Ganich, Ruslan F.; Zabludovsky, Volodymyr O.; Artemchuk, Viktor V.; Zelenko, Yuliia V.; Marcul, Ruslan V.
ENG: The paper presents the results of studying the phase composition of iron-nickel alloys obtained by unsteady electrolysis. It was found that the use of a unipolar pulse current leads to a significant increase in the crystallization overvoltage at the crystallization front at the moment of the pulse action, which affects the component composition of the coatings. The phase composition of the alloys formed at the cathode differs from that shown in the iron-nickel equilibrium diagram.
Phenomena Induced by UV Irradiation in PbMoO4 Single Crystal
(Taylor & Francis, 2020) Bochkova, T. M.; Trubitsyn, Mykhailo P.; Volnyanskii, M. D.; Bondar, D. S.; Volnyanskii, Dmytro M.
EN: Electrical properties and optical absorption of PbMoO4 single crystal were studied after UV irradiation. Anomalies of permittivity ε and conductivity σ were detected and attributed to the dipole centers induced by UV light. It was proposed that dipole centers were created by photoelectrons trapped by Mo within oxygen tetrahedra distorted by an oxygen vacancy VO. At high temperatures conductivity was nearly insensitive to UV irradiation. Additional optical absorption was observed in PbMoO4 single crystal after UV irradiation. It was argued that transfer of photoelectrons from lead to molybdenum groups was responsible for the photochromic effect found.
Photoinduced Effects in Single Crystals of PbO-MoO3 System
(Institute of Physics PAS, Poland, 2022) Bochkova, Tatiana; Bondar, Dmytro; Trubitsyn, Mykhailo P.; Volnianskii, M. D.; Volnyanskii, Dmytro M.
ENG: Purpose. Photoinduced changes in the optical absorption and dielectric properties of PbMoO4 and Pb2MoO5 crystals are considered. Differences in the manifestation of the photochromic effect in both crystals are associated with differences in their crystal structure. It is assumed that the photodielectric effect in the PbMoO4 and Pb2MoO5 crystals is due to the presence of the same anionic complexes. Methodology. Single crystals of PbMoO4 and Pb2MoO5 were grown in air from melt by the Czochralskii method. High-temperature treatment of the PbMoO4 crystals in air was carried out in a muffle furnace at 1200 K. The annealing time in the experiments varied from 2 to 90 h. Annealing of Pb2MoO5 crystals in vacuum was carried out at 1000 K during 1–2 h. The optical transmission spectra were measured at 295 K on the crystal doubly polished plates using a “Specord M-40” spectrophotometer. The photochromic coloration was observed after irradiation by light of Hg lamp during 2–5 h. Colored samples were returned to the initial state by annealing at 700–800 K in air for 2 h. Permittivity " was measured in the AC field by the four-wire method using a Keysight E4980AL LCR Meter at different frequencies (f = 1–10 kHz) in the temperature interval 290–700 K. Findings. One can assume that the photodielectric effect has the same nature and can be attributed for the common for both PbMoO4 and Pb2MoO5 crystals coordination complexes, i.e., molybdenum–oxygen tetrahedra. The dipole defects contributed to the photodielectric effect can be associated with Mo–O tetrahedra distorted by oxygen vacancy and photoelectrons capture. Hopping of VO through Mo–O tetrahedra vertices is accompanied by re-orientations of dipole moments of (MoO3)- complexes. Originality. Photoinduced changes in optical absorption and dielectric properties of PbMoO4 and Pb2MoO5 crystals are considered. The model of the mechanism of such changes of the power is offered. Practical value. The obtained conclusions will help to predict the influence of the composition of single crystals of acousto-optical materials of this series on their properties of practical value - optical absorption, optical stability..
Pulse Current Electric Rhodium Plating
(Eugen G. Leuze Verlag, 2021) Shtapenko, Eduard Ph.; Zabludovsky, Vladimir A.; Tytarenko, Valentina V.; Garnich, Ruslan Ph.
EN: The paper covers the study of the structure and properties of rhodium coatings obtained by pulse current from an aqueous electrolyte solution containing no surfactants. The authors determined the optimal parameters of the pulse current that forms finer-crystalline, dense and hard coatings. The use of pulse unipolar current made it possible to obtain high-quality rhodium coatings without the use of surfactants.
Quantum Mechanical Approach for Determining the Activation Energy of Surface Diffusion
(Физико-технический институт им. А.Ф. Иоффе Российской академии наук, Санкт-Петербург, 2020) Shtapenko, Eduard Ph. ; Tytarenko, Valentyna V.; Zabludovsky, Volodymyr O.; Voronkov, Eugene O.
ENG: A quantum mechanical approach was proposed to determine the activation energy of surface diffusion for copper, nickel, zinc and iron atoms adsorbed on a copper substrate during electrocrystallization for various overvoltages of the substrate. The activation energy of surface diffusion was calculated from the crystal total energy. An increase in the activation energy of surface diffusion with increasing surface potential is associated with an increase in the binding energy between the ad-atom and the substrate.
Quantum-Mechanical Modeling of the Interaction between Carbon Nanostructures and Metal Ions
(Pleiades Publishing, Ltd, 2021) Tytarenko, Valentyna V.; Shtapenko, Eduard Ph. ; Voronkov, Eugene O.; Zabludovsky, Volodymyr O.; Kolodziejczyk, Wojciech; Kapusta, Karina; Kuznetsov, Vitaliy N.
EN: In order to investigate a deposition mechanism, authors have proposed a set of quantum chemical models for formation of fullerene C60 and single-wall carbon nanotubes (SWNTs) C48 metal complexes with Co, Ni, Cu, and Zn. Obtained results proving that adsorption of Co, Ni, Cu, Zn ions on a surface of fullerene C60 and SWNT C48 from the aqueous solution of electrolytes is possible with formation of stable metal-doped carbon nanoparticle complexes. Minimum energy complexes of C60-Co and C60-Cu have corresponded to the structure where ion is located above the center of C6 cell. Meanwhile, C60-Ni complex reach a minimum energy when ion is above the middle of a C-C bond, and for C60-Zn complex the most stable conformation is the one when ion is upon the carbon atom. All the optimized structure for metal complexes with C48 has shown ions been located above the C6 cell’s center.
Solid-Phase Synthesis and X-Ray Analysis of the Charge for Growing Acousto-Optic Pb2MoO5 Crystals
(Дніпропетровський національний університет ім. Олеся Гончара, 2016) Volnyanskaya, I. P.; Trubitsyn, Mykhailo P.; Volnyanskii, Dmitriy M.; Kolessov, V. I.
EN: Growing single crystals of double lead molybdate Pb2MoO5 is usually accompanied by the appearance of additional phases of PbO–MoO3 system. To improve quality of the grown crystals, it is necessary to provide single phase composition of the charge used. In the paper the regimes of the charge solid-phase synthesis are varied and the phase composition of the obtained charge is studied for the first time. The initial charge stoichiometry, number of stages of synthesis procedure, heating rate, temperature, and time of synthesis are varied in the experiment. X-ray phase analysis is performed for a number of the charge samples obtained under different technological conditions of solid-phase synthesis. It is shown that the appropriate choice of the synthesis regimes make it possible to reduce significantly the content of PbO–MoO3 impurity phases in the charge. The obtained results should make for increasing quality of Pb2MoO5 single crystals which are promising for use in acousto-optic devices.
Soliton Solutions of Logarithmic Wave Equation and their Application for Polycrystalline Metals
(IOP Publishing Ltd., United Kingdom, 2019) Kraiev, M.; Domina, K.; Kraieva, V.; Zloshchastiev, K. G.
EN: Wave equations with logarithmic nonlinearity are applied to Korteweg-type materials which can undergo liquid-solid or liquid-gas phase transitions. One of predictions of the theory is a periodical pattern for inhomogeneities of density, which can occur in the form of bubbles or cells. Such inhomogeneities are described by soliton and solitary wave solutions of the logarithmic wave equation in the vicinity of a liquid-solid phase transition. During the solidification process, these inhomogeneities become centers of nucleation of grains. Previous works were dealing with generic natural silicate materials in geophysics, such as magmas in volcanic conduits, where the (approximately) periodical flows and structures were observed. Here we report an experimental evidence of a large-scale periodicity in structure of grains in the structural steel S235/A570 Grade 36, copper C-Cu/C14200, stainless steel X10CrNiTi18-10/AISI 321, and aluminium-magnesium alloy 5083/5056.
Some Peculiarities of Motion of Neutral And Charged Test Particles in the Field of a Spherically Symmetric Charged Object in General Relativity
(Springer US, 2011) Gladush, Valentin D.; Galadgyi, Marina V.
EN: We propose the method of investigation of radial motions for charged and neutral test particles in the Reissner-Nordström field by means of mass potential. In this context we analyze special features of interaction of charges and their motions in General Relativity and construct the radial motion classification. For test particles and a central source with charges q and Q, respectively, the conditions of attraction (when qQ > 0) and repulsion (when qQ < 0) are obtained. The conditions of motionless test particle states with respect to the central source are investigated and, in addition, stability conditions for such static equilibrium states are found. It is shown that stable states are possible only for the bound states of weakly charged particles in the field of a naked singularity. Frequencies of small oscillations of test particles near their equilibrium positions are also found.
Structure and Properties of Composite Nickel Coatings Deposited by Means of Programmable Pulsed Current under Laser Irradiation
(Pleiades Publishing, 2019) Tytarenko, Valentyna V.; Zabludovsky, Volodymyr O.; Shtapenko, Eduard Ph.
ENG: A method for the formation of composite electrolytic coatings in the process of electrodeposition in an electrolyte with ultradisperse diamond (UDD) particles in the programmable pulsed current regime under simultaneous laser irradiation has been developed. This method provides the layer-by-layer deposition of gradient nickel coatings 15–20 μm in thickness with a variable content of UDD particles along their depth. The amount of UDD particles is minimal (0.10–0.13 at %) in the layers deposited in the initial period of this process, whereas the concentration of UDD particles in the layers formed at the later process stages grows to 0.19–0.26 at %. The concentration gradient of UDD particles along the depth improves the adhesion properties and wear resistance of coatings and provides a 16% decrease in the consumption of UDD particles with a local increase in the concentration of UDD particles in a coating to 0.32 at %.
Structure of Iron-Nickel Coatings Obtained by Using Pulse Current
(Прикарпатський національний університет імені Василя Стефаника, Івано-Франківськ, 2019) Ganich, Ruslan Ph.; Zabludovsky, Volodymyr O.; Artemchuk, Viktor V.
EN: The paper presents the research results concerning the structure of iron-nickel alloy films obtained with pulse unipolar current from an electrolyte solution. It is shown that under the conditions of unsteady electrocrystallization there are processes on the cathode that lead to the formation of highly nonequilibrium structures and the change in the growth nature of the coating from columnar to layer-by-layer one.
Адгезионная прочность никелевых и цинковых покрытий с медной основой, электроосажденных в условиях внешней стимуляции лазерным излучением
(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпропетровськ, 2013) Дудкина, Валентина Васильевна
RU: Цель. Исследование влияния лазерного излучения на прочность сцепления никелевых и цинковых покрытий с медной основой и изучение начальных стадий кристаллизации пленок никеля и цинка. Методика. Электроосаждение никелевых и цинковых пленок из стандартных сульфатных растворов электролитов осуществлялось на лазерно-электролитических установках, построенных на базе газоразрядного СО2-лазера и твердотельного рубинового лазера КВАНТ-12. Адгезионную прочность металлических покрытий с основой определяли качественно (методом нанесения сетки царапин и методом многократного изгиба) и количественно (путем вдавливания алмазной пирамиды в границу раздела «покрытие-основа» на боковом шлифе). Спектральный микроанализ элементного состава границы раздела «пленка-подложка» производился на РEMMA-102-02. Результаты. Применение лазерного облучения прикатодной области в процессе электроосаждения металлических покрытий способствует повышению прочности сцепления покрытий с основой. Результаты испытаний адгезионной прочности пленок и спектральный микроанализ элементного состава границы раздела «пленка-подложка» показали, что при лазерно-стимулированном электроосаждении имеет место диффузионное взаимодействие между элементами покрытия и поверхностью основного металла, в результате которого металл покрытия диффундирует в основной металл, образуя переходной диффузионный слой, способствующий повышению прочности сцепления покрытий с основой. Научная новизна. Установлено, что увеличение энергии ионов в двойном электрическом слое при взаимодействии с лазерным излучением влияет на величину катодного пресыщения на стадии кристаллизации, а, следовательно, на глубину проникновения ионов осаждаемого металла в основной метал, что приводит к возрастанию адгезионной прочности. Практическая значимость. На основании результатов исследования структуры и механических свойств никелевых и цинковых металлических пленок, полученных при лазерно-стимулированном режиме электроосаждения, установлена их связь с параметрами лазерного излучения. Применение лазерного излучения позволяет, в зависимости от режима электроосаждения (гальваностатического или потенциостатического), получать как равновесную структуру, так и наоборот, формировать более неравновесную структуру.
Анализ состава неравновесных фаз в бинарных сплавах молибдена и вольфрама на основе представлений о межатомном взаимодействии компонентов
(Днепропетровский национальный университет железнодорожного транспорта имени академика В. Лазаряна, Днепропетровск, 2010) Дорогань, Татьяна Евгеньевна
UK: Роботу присвячено вивченню формування фазового складу електроосаджених і швидкозакристалізованих сплавів молібдену і вольфраму із залізом, кобальтом, нікелем. Досліджено взаємозв’язок потенціалу катода і швидкості формування покриттів з їх структурою і складом. Знайдено спільні закономірності для перерахованих систем, які пов’язані з характером міжатомної взаємодії компонентів. Здійснено обчислення концентраційного інтервалу існування гомогенних металевих покриттів із застосуванням іонізаційних потенціалів складових. Розвивається напрям прогнозування структури в результаті аналізу загальних закономірностей нерівноважної кристалізації.
Ближний порядок в сплавах Cr–C, электроосаждённых импульсным током
(Институт металлофизики им. Г. В. Курдюмова НАН Украины, 2018) Гуливец, Алексей Николаевич; Баскевич, Александр Семенович
RU: Методами рентгеновского анализа изучен ближний порядок в аморфных сплавах Cr–C, электроосаждённых импульсным током. Установлено, что в аморфном состоянии области сплавов с ближним порядком характеризуются упорядоченным расположением атомов, подобным ОЦК-структуре.
Визначення енергії активації поверхневої дифузії з позицій теплових коливань атомів
(Прикарпатський національний університет імені Василя Стефаника, 2021) Сироватко, Ю. В.; Штапенко, Едуард Пилипович
UK: В роботі представлено теоретичний розрахунок енергії активації поверхневої дифузії ад-атомів по поверхні підкладки як теплової енергії, визначеної методом, що оснований на теплових коливаннях атомів кристалічної решітки. Коливання атомів розглядаються з позицій квазикласичної квантової механіки як коливання гармонічних осциляторів з деякою середньогеометричною частотою та амплітудою в параболічній потенційній ямі. При цьому потенційна яма має невелику від’ємну частину, розміри якої визначає амплітуда коливань. Значну частину параболічної ями складають позитивні значення енергії. Потенційний бар’єр формується при взаємодії позитивних значень енергії параболічних ям поряд розташованих атомів кристалічної решітки. Ад-атом при перескоку у сусіднє положення на поверхні підкладки повинен мати необхідну енергію щоб вийти з потенційної ями, що має від’ємні значення енергії, та при русі подолати потенційний бар’єр, що створюють позитивні значення енергій ям сусідніх атомів. Таким чином була розрахована теплова енергія, необхідна для переміщення ад-атома, що складає енергію активації. В роботі показано, що отримані результати енергій активації поверхневої дифузії нікелю, міді, цинку та заліза по поверхні мідної підкладки задовільно співпадають з результатами, що розраховані іншим методом.
Властивості плівок Fe-Ni-P, отриманих імпульсним струмом
(Прикарпатський національний університет імені Василя Стефаника, Івано-Франківськ, 2012) Ганич, Руслан Пилипович; Артемчук, Віктор Васильович
UKR: Представлено результати дослідження впливу імпульсного струму на структуру і фізико-механічні властивості електроосаджених плівок Fe-Ni-P сплавів. Показано, що на їх структуру і властивості суттєво впливає не тільки концентрація фосфору, але і нерівноважні умови кристалізації викликані імпульсними режимами осадження. Встановлено, що коерцитивна сила і намагніченість насичення плівок, осаджених при великих значеннях величини катодної поляризації вище ніж у плівок, отриманих в більш нерівноважних умовах.
Влияние высоких перенапряжений при электрокристаллизации на коррозионную стойкость пленок Co-P
(Днепропетровский национальный университет железнодорожного транспорта имени академика В. Лазаряна, Днепропетровск, 2009) Заблудовский, Владимир Александрович; Гуливец, Алексей Николаевич; Дудкина, Валентина Васильевна
UK: Електрохімічним та гравіметричним методами досліджено вплив високих перенапруг при електроосадженні на корозійно-електрохімічну поведінку аморфних плівок Со-Р, отриманих осадженням із водяного розчину електроліту. Встановлено, що сплави, осаджені при більш високих перенапругах на катоді, виявляють більш високу корозійну стійкість.
Влияние постоянного магнитного поля на сопротивление деформации и упрочнение металлов
(Витебский государственный технологический университет, Витебск, Беларусь, 2018) Краев, Максим Валериевич; Краева, Виолетта Святославовна
RU: Показано, что магнитное поле влияет на интенсивность упрочнения металлов в процессе деформации, что зависит от магнитных свойств металлов и вида напряженно-деформационного состояния при их обработке давлением.
Влияние частиц ультрадисперсных алмазов на структуру и свойства электролитических никелевых покрытий
(Інститут металофізики ім. Г.В. Курдюмова НАН України, Київ, 2016) Титаренко, Валентина Васильевна; Заблудовский, Владимир Александрович
В работе рассмотрено влияние частиц ультрадисперсных алмазов на структурообразование и эксплуатационные свойства композиционных электролитических покрытий на основе никеля, полученных с помощью постоянного и импульсного токов. Результаты исследований показали, что при импульсных режимах электроосаждения формируются мелкозернистые, плотноупакованные покрытия, имеющие более неравновесную структуру роста с большей плотностью распределения частиц ультрадисперсного алмаза в покрытии, что повышает микротвёрдость и износостойкость никелевых композиционных электролитических покрытий.
Вплив лазерного випромінювання на кінетику процесу електрокристалізації плівок нікелю і цинку
(Прикарпатський національний університет імені Василя Стефаника, Івано-Франківськ, 2013) Заблудовський, Володимир Олександрович; Дудкіна, Валентина Василівна
UK: В рамках класичної теорії зародкоутворення Зельдовича і механізму прямого приєднання адсорбованих атомів досліджена кінетика утворення і росту поверхневих зародків при лазерно-стимульованому електроосадженні. Розраховані значення швидкості утворення і росту поверхневих зародків для режимів електроосадження плівок нікелю і цинку за допомогою постійного струму і в умовах зовнішньої стимуляції лазерним випромінюванням.
Вплив лазерного випромінювання на процес електроосадження плівок нікелю
(Прикарпатський національний університет ім. Василя Стефаника, Івано-Франківськ, 2011) Дудкіна, Валентина Василівна; Заблудовський, Володимир Олександрович; Штапенко, Едуард Пилипович
UK: Встановлено вплив лазерного випромінювання на процес електроосадження плівок нікелю. Визначений вклад пондероматорної дії лазерного випромінювання в інтенсифікацію процесу електроосадження плівок нікелю.