2304-9782, 2618-8686, 2405-7223 18 2 2025 1-164

RAR RUS 9-21 0000-0001-8179-3169 Alferov University Goltaev Aleksandr 0000-0001-7521-3754 Alferov University, RAS Fedina Sergey fedina.serg@yandex.ru 0000-0001-5547-9387 Alferov University Fedorov Vladimir fedorov_vv@spbstu.ru 0000-0002-8661-4083 Alferov University Mozharov Alexey mozharov@spbau.ru

St. Petersburg, Russian Federation

0000-0001-8440-494X Alferov University Novikova Kristina novikova_k@spbau.ru

St. Petersburg, Russian Federation

0000-0002-3503-7458 St. Petersburg Electrotechnical University "LETI" Maksimova Alina A. deer.blackgreen@yandex.ru 0000-0002-4894-6503 Alferov University Baranov Artem I. baranov_art@spbau.ru

St. Petersburg, Russian Federation

0000-0002-3640-677X Ioffe Institute Kaveev Andrey kaveev@mail.ioffe.ru

St. Petersburg, Russian Federation

Peter the Great St. Petersburg Polytechnic University Pavlov Alexander a.pavlov@physics.spbstu.ru 0009-0006-3064-4175 Alferov University Miniv Dmitriy 0000-0003-4123-4375 Peter the Great St. Petersburg Polytechnic University Ustimenko Ratmir ustimenko_rv@spbstu.ru

St. Petersburg, Russian Federation

Peter the Great St. Petersburg Polytechnic University Vinnichenko Maxim mvin@spbstu.ru 0000-0001-9792-045X Peter the Great St. Petersburg Polytechnic University Mukhin Ivan muhin_is@spbstu.ru Infrared photodetectors based on InAsP epitaxial nanowires on silicon In the paper, the upgraded technology of forming the epitaxial arrays of InAsP nanowires (NWs) synthesized on silicon substrates using molecular beam epitaxy has been presented. The optical and electrophysical properties of the NWs were studied. Based on the grown structures, a prototype of a short-wave infrared photodiode for a range from 1.2 µm to 1.9 µm was fabricated. Its band structures were numerically simulated. The temperature dependencies of the current-voltage characteristics and the spectral sensitivity of the photodetector prototype based on the NWs were experimentally studied. The external quantum efficiency of photoconversion of radiation with a wavelength of 1380 nm was found to be about 0.25% at 100 K. 10.18721/JPM.18201 621.383.52 InAsP silicon substrate molecular beam epitaxy nanowires photodetector quantum efficiency https://physmath.spbstu.ru/article/2025.80.1/ 01_9-21_18(2)2025.pdf

SCO RUS 22-29 0009-0001-6034-7757 Pacific National University Obrazcov Kirill 2018102293@pnu.edu.ru 0000-0002-5410-8661 Computing Center of the Far Eastern Branch of the Russian Academy of Sciences Chibisov Andery 0000-0001-7466-086X Omsk State University Named after Dostoevsky Mamonova Marina mamonovamv@omsu.ru The influence of hole states on the electronic and electrostatic properties of 2D layers based on the silicon-germaniumsilicon heterostructure The performance of a hole qubit in the Si/Ge/Si heterostructure is considered in this work. For this purpose, a quantum mechanical study using density functional theory and the pseudopotential method has been carried out. The zone structure and density of electronic states were constructed for the elementary structure. It was found that the bulk of these states are localized in the energy range from –2 to –4 eV. For the constructed supercell the yield work was calculated and the contribution of electron hole to the electrostatic potential of the system was evaluated. The analysis of the obtained results showed that the change of the yield work in the system is associated with the shift of the energy vacuum level. 10.18721/JPM.18202 537.9:004.94 silicon germanium density functional theory two-dimensional layer work function heterostructure https://physmath.spbstu.ru/article/2025.80.2/ 02_22-29_18(2)2025.pdf

RAR RUS 30-40 0000-0002-4318-7050 Peter the Great St. Petersburg Polytechnic University Antonova Olga antonova_ov@spbstu.ru 0009-0003-5702-2251 Peter the Great St. Petersburg Polytechnic University Ivanov Maksim ivanov.m@compmechlab.ru 0000-0002-1025-0148 Peter the Great St. Petersburg Polytechnic University Mikhailov Aleksandr michailov@compmechlab.com 0009-0002-2129-1591 LLC “Tetral” Kuzmin Valerii Application of mathematical modeling for describing the behavior of layered panels with a tetrahedral core In the paper, mathematical modeling methods for describing the behavior of sandwich panels with a tetrahedral core under various loads have been used, and a series of numerical calculations carrying out by the ANSYS software. In so doing the previously obtained effective elastic characteristics were taken, which made it possible to replace the direct modeling of the tetrahedral core structure with elements of a simple form using orthotropic material with equivalent characteristics. The problem of the plate’s three-point bending was solved, and a deformed state and deflection character of the panel were analyzed. The necessity of applying the heteromodular elasticity theory when modeling such objects and of taking into account the effective elastic characteristics obtained by tension and compression of the periodicity cell was established. Recommendations were given for the use of periodicity cells when computing the iterative changes in material properties and effective characteristics obtained during tension and compression. 10.18721/JPM.18203 539.3 tetrahedral core layered panel effective elastic characteristics finite element method https://physmath.spbstu.ru/article/2025.80.3/ 03_30-40_18(2)2025.pdf

RAR RUS 41-48 0000-0002-6210-4003 Peter the Great St. Petersburg Polytechnic University Ermak Sergey 0000-0003-0346-8349 Peter the Great St. Petersburg Polytechnic University Semenov Vladimir vladimir_semenov@mail.ru

Russia, 195251, St.Petersburg, Polytechnicheskaya, 29

0009-0005-8838-6845 Peter the Great St. Petersburg Polytechnic University Sergeeva Maria The effect of the magnetic field on the shielding efficiency in a rubidium atomic clock The paper presents the experimental study results of the dependence of the longitudinal shielding coefficient of a magnetic shield (in the direction of the shield axis) on the strengths and mutual orientation of the operational internal and additional external magnetic fields of a small-sized rubidium atomic clock (RAC). In this case, an additional field magnetizes the RAC’s magnetic shield from the outside and penetrates inside it. The significant influence of these fields in their interrelation on the shielding properties of the magnetic shield of the RAC has been found. The obtained results allowed us to determine the longitudinal RAC-shielding coefficient at the effective values of the operational and additional magnetic fields and, as a consequence, to compensate for the effect of geomagnetic field variations on the frequency of the onboard RAC. 10.18721/JPM.18204 53.098 rubidium atomic clock magnetic field magnetic screen longitudinal shielding coefficient https://physmath.spbstu.ru/article/2025.80.4/ 04_41-48_18(2)2025.pdf

RAR RUS 49-59 0000-0001-8594-9423 Peter the Great St. Petersburg Polytechnic University Kuptsov Vladimir kuptsov@spbstu.ru The X-ray absorption immersion technology for enrichment of diamond ores: Physical foundations and practical implementation The paper presents physical principles of X-ray absorption immersion technology (XRAIT) based on recording X-ray radiation passed through diamond-containing ore, pore spaces between the pieces of which are preliminarily filled with an immersion medium (IM). The energy range of X-ray photons where the diamond is more transparent than the ore components has been determined. Based on the proposed approximation of the mass attenuation coefficients of elements by the sum of two power functions, a justification for a conscious choice of the mass attenuation coefficient of the IM equal to the average value for all ore components was carried out taking into account their weight content. An optimal composition of the IM in the form of a bulk material, namely aluminum-zinc alloy powder, was proposed. Experiments conducted on a developed and manufactured prototype of the separator confirmed the possibility of using the XRAIT with significant advantages over analogues. 10.18721/JPM.18205 622.7 X-ray absorption technology immersion medium mass attenuation coefficient X-ray radiation diamonds https://physmath.spbstu.ru/article/2025.80.5/ 05_49-59_18(2)2025.pdf

RAR RUS 60-68 0000-0003-0985-5964 Institute for Analytical Instrumentation of the RAS Berdnikov Alexander asberd@yandex.ru 0009-0001-8247-6410 Peter the Great St. Petersburg Polytechnic University Egorova Anastasia 0000-0002-6162-9481 Peter the Great St. Petersburg Polytechnic University Krasnova Nadezhda n.k.krasnova@mail.ru 0000-0002-0873-8849 Institute for Analytical Instrumentation of the Russian Academy of Sciences Masyukevich Sergey 0000-0003-3514-8577 Peter the Great St. Petersburg Polytechnic University Solovyev Konstantin k-solovyev@mail.ru

Russia, 195251, St.Petersburg, Polytechnicheskaya, 29

The influence of field misalignment and electric field asymmetry on the stability zones of a combined ion trap This study continues a series of articles devoted to the operating features of ion-optical devices with periodic electric power supply and constant homogenous magnetic field, used in mass spectrometers. It has been shown how the structure of combined ion trap stability diagram is changed when the trap configuration deviates from the ideal one. The influence of an angle between the electric field symmetry axis and a magnetic field direction as well as the influence of the electric field asymmetry on the pattern of stability zones were found. The results obtained are worthy of use both for estimating the impact of manufacturing defects and for designing new nonclassical ion traps. 10.18721/JPM.18206 621.384.8 combined ion trap stability zones mass spectrometry ion confinement https://physmath.spbstu.ru/article/2025.80.6/ 06_60-68_18(2)2025.pdf

RAR RUS 69-81 0000-0001-9626-7612 Ioffe Institute Ryabko Andrey

St. Petersburg, Russian Federation

0009-0009-6273-1478 Ioffe Institute of RAS Ovezov Maksat 0000-0003-0195-8870 Maximov Alexander aimaximov@mail.ru 0000-0002-6953-9958 St. Petersburg Electrotechnical University "LETI" Permiakov Nikita nvpermiakov@etu.ru Belarusian State University of Informatics and Radioelectronics Tuchkovskiy Alexander a.tuchkovskij@bsuir.by 0000-0002-6796-8994 Belarusian State University of Informatics and Radioelectronics Igor A. vrublevsky@bsuir.edu.by

6 Petrus Brovka St., Minsk, 220013, Republic of Belarus

0000-0002-4181-6669 St. Petersburg Electrotechnical University "LETI" Muratova Ekaterina 0000-0001-5449-4446 Ioffe Institute Aleshin Andrey aleshin@transport.ioffe.ru

St. Petersburg, Russian Federation

0000-0001-6500-5492 St. Petersburg Electrotechnical University "LETI" Moshnikov Vyacheslav vamoshnikov@mail.ru Polycrystalline films of MAxMEA1−xPbI3 hybrid perovskites obtained by the solution method: Crystallization and morphology In this work, the morphological features of polycrystalline films of hybrid perovskites MAxMEA1−xPbI3 formed by a single-stage centrifugation method from DMF and DMSO solutions (4:1) have been investigated. The results of the studies showed that an increase in the proportion of monoethanolammonium in MAxMEA1−xPbI3 led not only to a change in the absorption spectra and an increase in the interplanar distances of the crystal lattice, but also to a significant change in the morphology of the films from elongated split crystallites to a uniform coating of nanocrystallites. An increase in the proportion of monoethanolammonium iodide in the solution also improved the wettability of solutions and the continuity of the coating of substrates with hybrid perovskite MAxMEA1−xPbI3 without additional surface activation processes. The increased band gap of MAxMEA1−xPbI3 compared to MAPbI3 makes these hybrid perovskites attractive for use in tandem solar cells. 10.18721/JPM.18207 538.91 hybrid perovskites polycrystalline film solar cell split crystallite morphology crystallization https://physmath.spbstu.ru/article/2025.80.7/ 07_69-81_18(2)2025.pdf

RAR RUS 82-92 0000-0002-5736-6957 Kazan National Research Technological University Zagidullina Inna 0000-0003-4354-8984 Kazan National Research Technological University Guzhova Alina 0000-0001-9604-4769 Herzen State Pedagogical University of Russia Karulina Elena karulina@mail.ru 0009-0002-3569-4981 Herzen State Pedagogical University of Russia Kulemina Sofya The effect of PLA-based composite material history on its electret properties This study reveals the effects of manufacturing methods and composition of the films based on polylactic acid (PLA) and fine fillers of different nature (aerosil, white silica and starch) and concentration on the electret properties (EP). The methods were solution casting (I) and compression molding (II). PLA films manufactured via method II exhibited a significantly higher electret effect when subjected to unipolar corona discharge than the films obtained by method I. The difference in the EP was proved to be attributed to the presence of polar liquid molecules (trichloromethane, water) within the samples produced using method I enhancing the electrical conductivity of the samples. The samples showed a tendency for the EP parameters to increase when the dispersed particles of fine fillers were added to the pure PLA. An explanation for this phenomenon has been proposed. The composition of PLA with 4% white silica had the best electret properties. 10.18721/JPM.18208 538.915 electret polylactic acid polymer dispersed filler white silica aerosil starch https://physmath.spbstu.ru/article/2025.80.8/ 08_82-92_18(2)2025.pdf

RAR RUS 93-108 0000-0003-0542-0939 Gomel State Technical University named after P. O. Sukhoi Kiselevich Valentin

48 October Ave., Gomel, 246029, Republic of Belarus

An electrical lifetime of polymers in terms of the catastrophe theory The present study analyzes the known expressions establishing exponential and power relationships between the lifetime of polymer dielectrics and the strength of the electric field acting on them. The work notes the necessity of mathematical substantiation of the known power expression for the field dependence of electrical lifetime. We obtained the equation of dependence of the electrical lifetime of polymeric dielectrics on the value of the applied electric field strength within the framework of the mathematical catastrophe theory. The study has the performance of quantitative estimation of the parameters of this equation for paper, epoxy and polyethylene terephthalate electrical insulation. We established a good agreement between the literature experimental data and the field dependences of the electrical lifetime of polymers plotted by the proposed equation. The study analyses geometric images of the fold catastrophe function reflecting the nature of the change in the dimensionless parameter of the rate of damage accumulation in a polyethylene terephthalate film under varying electric field strength. The paper shows the prospect of using the mathematical apparatus of catastrophe theory to describe experimental regularities of changes in the electrical strength properties of polymer dielectrics in strong electric fields. 10.18721/JPM.18209 621.315.61: 51-74 polymer dielectric electrical lifetime electrical breakdown electric field strength catastrophe theory fold catastrophe https://physmath.spbstu.ru/article/2025.80.9/ 09_93-108_18(2)2025.pdf

RAR RUS 109-118 Peter the Great St. Petersburg Polytechnic University Zolotorevsky Nikolai zolotorevsky@phmf.spbstu.ru NRC “Kurchatov Institute” – CRISM “Prometey” Belikova Yulia belikjul@ya.ru 0000-0001-6732-7217 NRC “Kurchatov Institute” – CRISM “Prometey” Petrov Sergey 0000-0002-9431-7097 NRC “Kurchatov Institute” – CRISM “Prometey” Zisman Alexander Formation of bainite below martensite start temperature in quenching low carbon steel According to the phase transformation kinetics that we recorded by dilatometry in rapid cooling of low carbon steel, some amount of isothermal bainite appeared in the middle of martensitic temperature range. Presumably caused by adiabatic heating in the exothermal transformation, such an unexpected effect was confirmed by TEM data on the lath thickness, dislocation density and carbide particles. Furthermore, to assess a volume fraction of the detected bainite, statistics of crystal curvature (orientation gradient) was analyzed in terms of EBSD data. The combined analysis of results obtained using those three techniques suggests that certain amount of lath type bainite is formed not only below the martensite start temperature but also slightly above it. 10.18721/JPM.18210 538.91; 548.74 microstructure martensite bainite isothermal transformation quenching low carbon steel https://physmath.spbstu.ru/article/2025.80.10/ 10_109-118_18(2)2025.pdf

RAR RUS 119-131 0000-0003-0309-5917 Peter the Great St. Petersburg Polytechnic University Berdnikov Yaroslav berdnikov@spbstu.ru 0000-0003-3298-3702 Peter the Great St. Petersburg Polytechnic University Ivanishchev Dmitry ivanishchev_da@pnpi.nrcki.ru 0000-0002-3395-0454 Peter the Great St. Petersburg Polytechnic University Kotov Dmitry dmitriy.kotov@gmail.com 0009-0001-9974-0169 Peter the Great St. Petersburg Polytechnic University Malaev Mikhail mmalayev@gmail.com 0009-0007-9874-9819 Petersburg Nuclear Physics Institute named by B. P. Konstantinov of NRC «Kurchatov Institute» Riabov Andrei andrei.riabov@cern.ch Feasibility to measure the properties of charged K*(892) mesons and Σ(1385) baryons in collisions of bismuth nuclei at an energy of 9.2 GeV in the NICA collider using the MPD experimental setup We report results on a feasibility study of measuring the properties of K*(892)± and Σ(1385)± resonances in collisions of bismuth nuclei (Bi) at an energy of 9.2 GeV using the MPD detector at the NICA collider. The dependencies of the process’es key parameters on the transverse momentum for different intervals of centrality of Bi + Bi collisions were obtained in the rapidity range from –0.5 to +0.5 using model calculations. The evaluations of the mass resolution, detection efficiency of the MPD detector and the transverse momentum spectra for the K*(892)± and Σ(1385)± resonances were made. The sample size of Bi + Bi collision data that allowed the K*(892)± and Σ(1385)± resonances properties to be reconstructed with a sufficiently good accuracy to conduct a study of the K*(892)± and Σ(1385)± resonances production was estimated. 10.18721/JPM.18211 539.126.3, 539.126.6 bismuth nuclei collisions production resonance NICA collider MPD detector https://physmath.spbstu.ru/article/2025.80.11/ 11_119-131_18(2)2025.pdf

RAR RUS 132-143 0000-0003-4292-0959 Peter the Great St. Petersburg Polytechnic University Golovitski Alexander alexandergolovitski@yahoo.com An inverse problem of differential equation systems in connection with the study of semiconductor materials and biomedical processes This paper puts forward a new method of solving the problem for calculating the unknown and non-measurable parameters, that are included in a system of differential equations, whose solution adequately reproduces the given experimental data, but has no analytical form. The problems of this kind are often found in physical research of semiconductor materials, biomedical processes and in electronics. The novelty lies in the proposed idea of numerical calculations of partial derivatives which has made it possible to adapt the Levenberg – Marquardt method of non-linear approximations for solving the said problem. Our specific examples showed that calculation errors of the parameter values were not more than the experimental errors. 10.18721/JPM.18212 519.65, 53.088 inverse problem differential equation system indirect measurements Levenberg – Marquardt method https://physmath.spbstu.ru/article/2025.80.12/ 12_132-143_18(2)2025.pdf

RAR RUS 144-161 0000-0003-1457-8236 Peter the Great St. Petersburg Polytechnic University Ipatov Andrey andrei_ipatov@mail.ru

Russia, 195251, St.Petersburg, Polytechnicheskaya, 29

0009-0001-5775-2276 Peter the Great St. Petersburg Polytechnic University Kupriianov Genrikh henryweis3@gmail.com Collective excitations in the bulk doped semiconductor cadmium sulfide nanocrystals The excited states of nanosized CdS semiconductor crystals with bulk doping have been studied. It was demonstrated that the giant dipole resonance dominated in their photoabsorption spectra. Varying the potential barrier height at the nanoparticle boundary was shown to be able to cause a change in the character of the collective mode from the plasmonic-type electron density fluctuations to the dimensional quantization mode depending on the particle size and the number of free charge carriers. 10.18721/JPM.18213 538.9 semiconductor nanocrystal cadmium sulfide doping plasmon resonance multiparticle excitation https://physmath.spbstu.ru/article/2025.80.13/ 13_144-161_18(2)2025.pdf