2304-9782, 2618-8686, 2405-7223 17 3 2024 1-163

RAR RUS 7-16 0000-0001-5701-1171 National Research Lobachevsky State University of Nizhni Novgorod Revin Alexandr 0000-0001-8850-2651 National Research Lobachevsky State University of Nizhni Novgorod Konakov Anton Lobachevsky State University of Nizhni Novgorod Korolev Dmitry dmkorolev@phys.unn.ru

Nizhni Novgorod, Russian Federation

The electronic structure of gallium oxide nanocrystals doped with shallow donors The results of theoretical calculations of electronic states of the gallium oxide (Ga2O3) nanocrystals both doped with donor impurity and undoped have been presented in the paper. In the envelope function approximation, the structure, states and energy levels of size quantization in the nanocrystals were determined. According to our calculations, the electron-hole pair forms a bound state of the exciton type in the nanocrystal. The typical donor impurities in Ga2O3, such as silicon and tin, were shown to create bandgap states localized in a spatial domain being several times smaller than the nanocrystal’s volume. Forming a compact neutral pair, the electron and donor ions have no noticeable influence on the states of the optically excited electron-hole pairs. The effect of impurity implantation on recombination processes was also discussed. 10.18721/JPM.17301 538.915 nanocrystal gallium oxide electronic structure donor impurity quantum size effect https://physmath.spbstu.ru/article/2024.74.1/ 01_7-16_17(3)2024.pdf

RAR RUS 17-24 0000-0002-4894-6503 Alferov University Baranov Artem I. baranov_art@spbau.ru

St. Petersburg, Russian Federation

Alferov University Vtorygin Georgii piespogany@gmail.com

St. Petersburg, Russian Federation

0000-0002-0061-6687 Alferov University Uvarov Alexander lumenlight@mail.ru 0000-0002-3503-7458 St. Petersburg Electrotechnical University "LETI" Maksimova Alina A. deer.blackgreen@yandex.ru 0000-0001-6869-1213 Alferov University Vyacheslavova Ekaterina cate.viacheslavova@yandex.ru 0000-0002-7632-3194 Alferov University Gudovskikh Alexander gudovskikh@spbau.ru Admittance spectroscopy of boron phosphide heterostructures grown by plasma enhanced chemical vapor deposition on silicon substrates The study of BP layers and BP/n-Si heterojunctions formed by plasma enhanced chemical deposition on n-Si substrates has been carried out at a temperature of 350 °C using diborane and phosphine. The additional enhancement of hydrogen plasma power was established to make it possible to avoid pinning of the Fermi level at the BP/n-Si interface. Moreover, additional dilution with a hydrogen flow led to an increase in the BP layer conductivity, and the behavior of the current-voltage characteristic of the Au/BP/n-Si structure (golden electrode) became rectifying. Surface states of electrons at the BP/n-Si heterojunctions in all the samples and deep electronic levels with energy 0.58–0.65 eV in BP layers grown without the additional hydrogen flow were detected by admittance spectroscopy. 10.18721/JPM.17302 621.383.51 boron phosphide plasma enhanced chemical vapor deposition admittance spectroscopy interface states https://physmath.spbstu.ru/article/2024.74.2/ 02_17-24_17(3)2024.pdf

RAR RUS 25-35 0000-0002-4172-940X Alferov University Dvoretckaia Liliya 0000-0002-8661-4083 Alferov University Mozharov Alexey mozharov@spbau.ru

St. Petersburg, Russian Federation

0000-0002-7025-3527 National Research University “Higher School of Economics” Komarov Sergey serega.komarow@mail.ru

St. Petersburg, Russian Federation

0000-0001-6869-1213 Alferov University Vyacheslavova Ekaterina cate.viacheslavova@yandex.ru 0000-0003-3686-935X National Research University “Higher School of Economics” (St. Petersburg branch) Moiseev Eduard emoiseev@hse.ru 0000-0001-5547-9387 Alferov University Fedorov Vladimir fedorov_vv@spbstu.ru 0000-0001-9792-045X Peter the Great St. Petersburg Polytechnic University Mukhin Ivan muhin_is@spbstu.ru Creation of optical isolated GaP(NAs) microcavities on silicon This article presents the technology for the formation of optical microcavities based on the GaP(NAs) semiconductor material system on silicon. For the first time, a plasma etching mode which ensures the achievement of an aspect ratio of 5:1 and low roughness of the side walls has been proposed in etching layers of III–V groups. A technological approach was also put forward to ensure optical separation of the microcavity with the Si substrate, that being important for efficient localization of light in the photonic structure. The optical studies and numerical calculation showed the presence of modulations in the micro-photoluminescence spectra of microstructures caused by the appearance of Fabry – Perot resonances. This research is an important step in the development of the technology of creation and application of combined structures with silicon-based optical waveguides. 10.18721/JPM.17303 535.015 optical GaP(NAs) microcavity on Si plasma etching micro-photoluminescence spectrum https://physmath.spbstu.ru/article/2024.74.3/ 03_25-35_17(3)2024.pdf

RAR RUS 36-45 0000-0001-9604-4769 Herzen State Pedagogical University of Russia Karulina Elena karulina@mail.ru 0000-0001-5647-1854 Kazan National Research Technological University Galikhanov Mansour Herzen State Pedagogical University of Russia Castro Arata Rene recastro@mail.ru Herzen State Pedagogical University of Russia Reztsov Tikhon sunnyundeadjuvati@icloud.com 0000-0002-9402-5246 Military Space Academy Named after A. F. Mozhaysky Fomicheva Elena Relaxation of electric charge in polymer blends based on low-density polyethylene and copolymer of ethylene with vinyl acetate This paper presents the results of a study of polymer films based on a blend of low-density (high-pressure) polyethylene (LDPE, HPP) with a copolymer of ethylene and vinyl acetate (EVA, sevilen). The use of thermal activation, infrared and dielectric spectroscopy methods made it possible to describe the electric charge relaxation processes in the polymer blends investigated. The data obtained suggested the presence of an α-relaxation process in the samples in the temperature range 250–280 K. An increased value of the activation energy of this process was also found in the LDPE/EVA samples compared to that in the LDPE one. This effect has been interpreted as the appearance of deeper traps of charge carriers in the blends. The dependences obtained by dielectric spectroscopy indicated the presence of hopping conductivity in the subjects of research. 10.18721/JPM.17304 538.9, 539.23 polyethylene copolymer of ethylene with vinyl acetate thermostimulated depolarization thermo-activation spectroscopy https://physmath.spbstu.ru/article/2024.74.4/

RAR RUS 46-56 Alferov University Barykin Dmitrii d.a.barykin02@mail.ru 0000-0001-8973-3187 Alferov University Shugurov Konstantin 0000-0002-8661-4083 Alferov University Mozharov Alexey mozharov@spbau.ru

St. Petersburg, Russian Federation

0000-0001-9792-045X Peter the Great St. Petersburg Polytechnic University Mukhin Ivan muhin_is@spbstu.ru Numerical simulation of the tunnel effect in the gallium nitride heterostructure on silicon In this study, a numerical simulation of the tunnel effect in the n-GaN/p-Si heterostructure has been performed. Variations of band diagrams, current-voltage characteristics and cutoff frequencies of the diode heterostructures under study were obtained depending on the doping levels of GaN and Si. The dopant concentration values were found for implementing backward and tunnel diode modes. In the tunnel diode mode, the peak current density and maximal generation frequency were 24.6 kA/cm2 and 17 GHz, respectively. 10.18721/JPM.17305 537.9 tunnel effect simulation gallium nitride silicon nanowire tunnel diode https://physmath.spbstu.ru/article/2024.74.5/ 05_46-56_17(3)2024.pdf

RAR RUS 57-75 0000-0002-2653-6378 Moscow Aviation Institute (National Research University) Zemskov Andrei 0000-0002-1905-9438 Moscow Aviation Institute (National Research University) Vestyak Anatoly kaf311@yandex.ru 0000-0002-5694-9253 Institute of Mechanics, Lomonosov Moscow State University Tarlakovskii Dmitry A model of unsteady mechanodiffusion vibrations of a rectangular orthotropic Timoshenko plate with mixed edge fixing In the paper, the coupled elastic-diffusion processes arising as a result of unsteady bending vibrations of an orthotropic plate that has a cantilever fastening on one side and hinged support on the sides adjacent to the cantilever have been analyzed. For a mathematical description of physical and mechanical processes, the Timoshenko plate model supplemented with mass transfer equations taking into account the finite speed of propagation of diffusion flows was used. The solution algorithm was based on the use of the equivalent boundary conditions method allowing to express the solution to the problem posed through a known solution to some auxiliary problem of a given class. The nature of the interaction between mechanical and diffusion fields was simulated using the example of a bendable three-component plate. 10.18721/JPM.17306 539.3 elastic diffusion cantilever plate method of equivalent boundary conditions Timoshenko plate https://physmath.spbstu.ru/article/2024.74.6/ 06_57-75_17(3)2024.pdf

RAR RUS 76-86 0000-0003-1394-2681 Peter the Great St. Petersburg Polytechnic University Nikitina Elizaveta E-4237-2014 12784708700 0000-0001-9050-4453 Peter the Great St. Petersburg Polytechnic University Kapralova Victoria kapralova2006@yandex.ru

Russia, 195251, St.Petersburg, Polytechnicheskaya, 29

Peter the Great St. Petersburg Polytechnic University Sudar Nikolai sudar53@mail.ru 0000-0002-2149-2978 Peter the Great St. Petersburg Polytechnic University Studzinskii Vitalii svm.fl@mail.ru 0009-0004-2167-0019 Peter the Great St. Petersburg Polytechnic University Gerasimov Victor Electrical and optical properties of a nanocomposite based on polyvinyl alcohol and fullerenol This work presents the results of comparison of optical properties at room temperature and electrical characteristics of films of polyvinyl alcohol (PVA) and nanocomposite based on PVA with small additives of fullerenol C60(OH)44 in a wide frequency range (25 Hz – 1 MHz) at temperatures from 294 to 398 K. The addition of 2 wt.% fullerenol leads to a significant absorption of light by such a film in the UV region of the spectrum (IR spectra of both film samples were identical), as well as to a decrease in dielectric permittivity ε'. The ε'' frequency dependences of both films showed peaks in the low-frequency region, which shifted towards higher frequencies when the films were heated. The values of the activation energy of conduction at direct current for PVA and polymer nanocomposite were found to be about 1.5 eV. An explanation of the observed effects is proposed. 10.18721/JPM.17307 564.163.2, 539.199 polyvinyl alcohol fullerenol nanocomposite dielectric constant dielectric loss https://physmath.spbstu.ru/article/2024.74.7/ 07_76-86_17(3)2024.pdf

RAR RUS 87-96 0000-0001-6453-6523 Tashkent State Technical University Named after Islam Karimov Abduvayitov Akbarjon 0000-0001-5813-7518 Tashkent State Technical University Named after Islam Karimov Tashmukhamedova Dilnoza 0000-0002-9815-2111 Tashkent State Technical University Named after Islam Karimov Umirzakov Baltokhodja be.umirzakov@gmail.com

2, Universitetskaya St., Tashkent,100095, Uzbekistan

Tashkent State Technical University Bekpulatov Ilkhom bekpulatov85@rambler.ru

2 Universitetskaya St., Tashkent, 100095, Uzbekistan

0000-0001-6067-8196 Tashkent State Technical University Named after Islam Karimov Khujaniyozov Jumanazar Peter the Great St. Petersburg Polytechnic University Loboda Vera vera_loboda@mail.ru Effect of argon ion bombardment on the composition, electronic structure and physical properties of cadmium fluoride In the paper, the effect of bombardment with Ar+ ions on the composition, electronic and crystal structure of the surface layers of bulk single crystal samples and CdF2(111) films has been studied using the methods of Auger electron and ultraviolet photoelectron spectroscopy, high-energy electron diffraction and recording the angular dependences of the reflectance factor of inelastically reflected electrons. The effect of this bombardment on the density of states of valence electrons and energy band parameters of CdF2 was investigated for the first time. The degree of disorder of CdF2 into components and evaporation of fluorine from the surface layers was established to depend on the energy and dose of Ar+ ions. The complete evaporation of F in the form of a diatomic gas was shown for the first time to be observed in the energy range of 1 – 2 keV at a saturation dose. 10.18721/JPM.17308 544.227 epitaxial layer heterostructures ion bombardment Auger spectrum photoelectron spectrum disordered layer electron density of state https://physmath.spbstu.ru/article/2024.74.8/

RAR RUS 97-104 Tashkent State Technical University Named after Islam Karimov Donaev Sardor sardor.donaev@gmail.com

2, Universitetskaya St., Tashkent,100095, Uzbekistan

Tashkent State Technical University Named after Islam Karimov Shirinov Ganjimurod ganjimurod777@gmail.com

2, Universitetskaya St., Tashkent,100095, Uzbekistan

0000-0002-9815-2111 Tashkent State Technical University Named after Islam Karimov Umirzakov Baltokhodja be.umirzakov@gmail.com

2, Universitetskaya St., Tashkent,100095, Uzbekistan

Peter the Great St. Petersburg Polytechnic University Loboda Vera vera_loboda@mail.ru Influence of low-energy electron bombardment on the composition and structure of the gallium phosphide surface In the paper, the patterns of changes in the composition and structure of the surface layers of GaP(111) in bombardment by electrons with energies from 3 to 10 keV and doses in the range 1017 – 1020 cm–2 have been studied using the method of Auger electron spectroscopy and recording the angular dependence of the electron inelastic reflection coefficient. It was established that the surface layers of GaP were enriched with P atoms at E = 3 keV, and with Ga atoms at E = 10 keV. In both cases, the Ga atoms distribution profiles over the depth the sample were non-monotonic. The electron energy value at which an inversion of the surface composition took place was estimated. An analysis of the results obtained was given. 10.18721/JPM.17309 544.227 Auger electron spectroscopy nanosized phase electron bombardment surface concentration of atoms https://physmath.spbstu.ru/article/2024.74.9/ 09_97-104_17(3)2024.pdf

RAR RUS 105-117 0009-0008-0216-462X Peter the Great St. Petersburg Polytechnic University Astapov Yaroslav 0000-0003-2016-8612 Peter the Great St. Petersburg Polytechnic University Lukin Alexei lukin_av@spbstu.ru

Russian Federation, 195251, St. Petersburg, Polytechnicheskaya, 29

0000-0003-4425-9172 Peter the Great St. Petersburg Polytechnic University Popov Ivan popov_ia@spbstu.ru An analysis of the accuracy of shortwave and long-wave asymptotics for stationary Lamb waves in the isotropic layer In the paper, the exact and asymptotic approximate solutions for symmetric and antisymmetric Lamb waves in the homogeneous isotropic elastic film have been analyzed. Using the numerical methods of the theory of continuation of solutions of nonlinear equations, the dispersion curves were calculated for waves with different variability across the layer thickness. Based on the results obtained, the nature of the displacement field and the variability of oscillation forms depending on the wave number were studied. The asymptotic correctness of the Timoshenko and Euler – Bernoulli beam models as long-wave asymptotics of Lamb waves was analyzed. 10.18721/JPM.17310 534-16 Lamb waves Euler – Bernoulli beam model Timoshenko beam model bifurcation theory https://physmath.spbstu.ru/article/2024.74.10/ 10_105-117_17(3)2024.pdf

RAR RUS 118-133 LLC "Evolution Marine Digital" Afanasov Evgeny zhenya.afanasov@yandex.ru State Marine Technical University Kadyrov Sergey skadyrov@gmail.com 0009-0000-2883-2763 State Marine Technical University Sorokin Vadim Asymptotic methods for solving the Stokes problem for a flat contour The paper presents asymptotic methods for solving the problem of small harmonic oscillations of a flat contour immersed in an incompressible viscous liquid. In the case of large values of the dimensionless viscosity parameter, asymptotic approximations up to the third order have been obtained. In the case of small values of this viscosity parameter, the main term of the asymptotic of the hydrodynamic force on an arbitrary smooth contour was constructed and its form was proved not to depend on the shape of the contour. The results obtained were confirmed by an example of the problem of oscillations of an elliptical cylinder. 10.18721/JPM.17311 532.5.032 Stokes problem viscous incompressible fluid solid body vibrations elliptical cylinder https://physmath.spbstu.ru/article/2024.74.11/ 11_118-133_17(3)2024.pdf

RAR RUS 134-147 0000-0001-5874-5994 Peter the Great St. Petersburg Polytechnic University Novokshenov Aleksei novoksh_ad@spbstu.ru 0009-0008-6553-4077 Peter the Great St. Petersburg Polytechnic University Abdulin Ilya 0009-0004-9552-3433 Peter the Great St. Petersburg Polytechnic University Vershinin Denis A topology optimization algorithm for electroelasticity coupled problems A problem of applying topology optimization to elastic deformable bodies exposed to coupled electric and mechanical fields has been studied. The main goal was to find the optimal distribution of electric and mechanical properties in the given area, taking into account restrictions on the final volume of the structure. A topology optimization algorithm was formulated and implemented (as program code in Python) for bodies under the action of the coupled electric and mechanical fields. The algorithm included solving the coupled electroelasticity problem using the finite element method, analyzing derivatives of the objective function, and optimizing by the dual procedure within the method of moving asymptotes. The algorithm was tested in numerical experiments on the optimization problem of a piezoelectric actuator exposed to uniform or linearly distributed electric fields. As a result, the distributions of mechanical and electrical properties were obtained for various values of the stiffness coefficient. 10.18721/JPM.17312 539.3 topology optimization finite element method method of moving asymptotes piezoelectric actuator https://physmath.spbstu.ru/article/2024.74.12/ 12_134-147_17(3)2024.pdf

RAR RUS 148-160 0000-0001-8794-2938 National Autonomous University of Mexico (UNAM) Teófilo-Salvador Eduardo mca.ts.eduardo2015@gmail.com Individual behavior of gas hydrodynamics from pairs of isolated galaxies in interaction The hydrodynamic behavior of the gas of a selected pair of interacting galaxies has been reviewed based on numerical simulation using Illustris and IllustrisTNG. 210 halos were identified visually, using the Explorer; but their number was reduced due to selection taking into account found distances, masses and particle emission conditions, then the halos were refined and received specific cuts using Python. Among them, 34% did not interact at all, due to asymmetries ranging from 18 to 74%. The pair with ID 473420-473421 turned out to be the best interacting pair, and it was most marked at z = 1 and 5. This sample provided more information about the behavior of the gas present, such as the formation of tidal tails, with a relative velocity of 9 to 213 km/s. The density fields were affected by distribution velocities and radial motion in galaxy interaction processes, the gas flow created transitions between the two disks in the radial velocity field, with longer jets in regions of cold gas compared to those of hot one. 10.18721/JPM.17313 524.6 ID 473420-473421 pair of isolated galaxies numerical simulation https://physmath.spbstu.ru/article/2024.74.13/