Journal of the Belarusian State University. Physics
type: channel
publisher: Belarusian State University
language: en
publication name: Journal of the Belarusian State University. Physics
issn: 2520-2243
copyright: The authors who are published in this journal agree to the following: The authors retain copyright on the work and provide the journal with the right of first publication of the work on condition of license Creative Commons Attribution-NonCommercial. 4.0 International (CC BY-NC 4.0). The authors retain the right to enter into certain contractual agreements relating to the non-exclusive distribution of the published version of the work (e.g. post it on the institutional repository, publication in the book), with the reference to its original publication in this journal. The authors have the right to post their work on the Internet (e.g. on the institutional store or personal website) prior to and during the review process, conducted by the journal, as this may lead to a productive discussion and a large number of references to this work. (See The Effect of Open Access.)
items: Effect of thermal cycling and ultraviolet irradiation on epoxy polymers: the role of graphene filler
items: Synthesis and properties of Ag/TiO2/Ti heterostructures
items: Spectral and generation properties of new coumarins – benzopyrylium derivatives
items: Formation of epitaxial 3C-SiC layers on Si by rapid vacuum thermal processing
items: The regional nanosatellite constellation modelling formation by a piggyback launch from different spaceports
items: Uni- and multivariate calibration of tempe­rature from the neodymium fluorescence spectra in nanocrystals of yttrium-gadolinium oxide and yttrium-gadolinium garnet
items: Structure formation and peculiarities of crystallisation of lead-free tin – zinc alloys obtained by rapid solidification
items: «Uncanny valley» effect in holographic image transmission
items: Analysis of the reciprocal lattice of crystals with non-primitive Bravais cells
items: Equivalent circuits of FeCoZr-alloy nanoparticles deposited into Al2O3 and PZT dielectric matrices nanogranular composite films
items: Electrophysical characteristics of power MOSFETs additionally implanted with nitrogen ions
items: Thermal and thermoelectric properties of ceramics based on zinc oxide alloyed with iron
items: Influence of high-temperature ion irradiation on nanostructured TiAlN coatings
items: Classification of Norway spruce drying states on the basis of reflection spectra
items: Liquid crystalʼs photoalignment for formation of phase profiles via geometric phase distribution
items: Estimation of the contribution of scattered ionising radiation to the dosimeter readings during measurements inside a low-background chamber
items: Determination of the Bessel light beam cone parameter by Fourier analysis of the diametral distribution of the intensity
items: Method for studying the photostability of solar cells based on organic-inorganic perovskites using a confocal spectrometer
items: Analytical diagonalisation of the Hamiltonian of the quantum Rabi model in the Coulomb gauge
items: Charging properties of thin gate dielectrics, obtained by the method of rapid thermal processing
items: Hydrogen-phase naklep as a result of single isothermal hydride transformations
items: The structure of rapidly solidified foil of Al – Bi alloys
items: Recording the dynamic polarisation gratings in pure nematic liquid crystal
items: Determination of the parameters of two-beam laser splitting of silicate glasses using regression and neural network models
items: Transport properties of two-component radium – halogen dilute gas media
items: Crystal growth and f – f transition intensities analysis of praseodymium ions in yttrium-aluminum orthoborates
items: Outlook for nuclear physics research in Belarus
items: Improving the efficiency of an industrial silicon solar cell by doping with nickel
items: Formation of holographic diffraction gratings in thin films of chalcogenide glassy semiconductors
items: Incoherent ultrarelativistic channeling particle scattering by electrons

Effect of thermal cycling and ultraviolet irradiation on epoxy polymers: the role of graphene filler
type: item
description: To evaluate the influence of near-Earth orbit factors on the structural features of epoxy polymer with graphene filler the effect of combined thermal cycling and ultraviolet irradiation under vacuum conditions (pressure 2 ⋅ 10– 4 Pa, temperature range from 15 to 160 °C; 4 and 10 thermal exposure cycles) on epoxy polymers based on ED-20 resin and amine hardener «Etal-45M» was studied. Two types of cured polymer samples (an unmodified polymer and a composite containing 1 wt. % graphene nanoplatelets) are considered. Optical and infrared spectroscopy in reflection mode was applied to record spectra from both the face (irradiated) and back surface of samples. A combined analysis of spectral and morphological data allowed to identify characteristic markers of polymer degradation, densification and structural modification induced by thermal cycling and ultraviolet irradiation. It was found that the unmodified polymer exhibits signs of degradation at the early stage of thermal cycling (4 cycles), whereas prolonged treatment (10 cycles) results in post-curing and structural stabilisation. The introduction of graphene enhances structural stability at the early stage, but with increasing number of cycles it initiates destructive processes on the surface of the sample due to interfacial interactions and localised absorption of ultraviolet radiation. The obtained results can be applied to the development of polymer composites for aerospace applications and to the assessing their durability.
subject: Condensed State Physics
  topic: section
subject: epoxy polymer
  topic: keywords
subject: graphene
  topic: keywords
subject: thermal cycling
  topic: keywords
subject: ultraviolet irradiation
  topic: keywords
subject: optical spectroscopy
  topic: keywords
subject: infrared spectroscopy
  topic: keywords
creator: Irina N. Parkhomenko
creator: Liudmila A. Vlasukova
creator: Ivan D. Parfimovich
creator: Alexander S. Kamyshan
rights: Copyright (c) 2026 Journal of the Belarusian State University. Physics https://creativecommons.org/licenses/by-nc/4.0
date: 2026-04-06
publication date: 2026-04-06
starting page: 53
ending page: 63
doi: 10.33581/2520-2243-2026-1-%p

Synthesis and properties of Ag/TiO2/Ti heterostructures
type: item
description: Ag/TiO2/Ti heterostructure was fabricated by electrochemical deposition method from a silver nitrate solution onto a titanium substrate with a thin titanium dioxide layer obtained via two-step chemical-thermal oxidation. Scanning electron microscopy analysis revealed that silver forms on the surface of the nanostructured titanium dioxide film predominantly as disordered complex tree-like structures (dendrites) with average dimensions of 1 × 8 μm, in this case, the formation of grains with a tendency toward clustering (cluster sizes up to 3.5 μm) was also observed. The metallic nature of the silver structures was confirmed by X-ray diffraction analysis. The photocatalytic activity of the Ag/TiO2/Ti heterostructure was determined with respect to the test contaminant rhodamine B in an aqueous solution (concentration 10 mg/L) upon exposure to ultraviolet radiation (wavelength 365 nm). The plasmonic activity of heterostructures with a lower detection threshold for the dye methylene blue at a concentration of 10–6 mmol/L when activated by a green laser (wavelength 532 nm) is shown. The obtained heterostructures, which combine photocatalytic and plasmonic properties, can be used to develop flow-through water purification and disinfection systems, as well as to create multifunctional substrates for real-time monitoring of organic pollutant degradation and for tracking photochemical reactions on the surface of such heterostructures.
subject: Condensed State Physics
  topic: section
subject: heterostructures
  topic: keywords
subject: silver
  topic: keywords
subject: titanium dioxide
  topic: keywords
subject: photocatalysis
  topic: keywords
subject: plasmonic structures
  topic: keywords
subject: bifunctional structures
  topic: keywords
creator: Sergey E. Maksimov
creator: Aleksey D. Sonnykh
creator: Dmitry V. Yakimchuk
creator: Shavkat I. Mamatkulov
creator: Olga A. Galkina
creator: Aleksey V. Баглов
creator: Liudmila S. Khoroshko
rights: Copyright (c) 2026 Journal of the Belarusian State University. Physics https://creativecommons.org/licenses/by-nc/4.0
date: 2026-04-10
publication date: 2026-04-10
starting page: 64
ending page: 71
doi: 10.33581/2520-2243-2026-1-%p

Spectral and generation properties of new coumarins – benzopyrylium derivatives
type: item
description: The spectral and generation parameters of coumarins, benzopyrylium derivatives, in ethanol and acetonitrile under coherent excitation were studied. It was found that the absorption spectra of the investigated compounds contain several maxima and the structuredness of the spectra is associated with their bichromophoric structure. It is shown that these organic dyes are bichromophoric compounds. It is noted that the nature of the substituents in positions 6 and 7 of the coumarin base and positions 6′ and 7′ of the benzopyrylium core determines their spectral-luminescent and lasing properties. It is demonstrated that the presence of substituents in certain positions of the coumarin base and the benzopyrylium core changes the conformation of the molecule and, accordingly, the dipole moments and oscillator strengths of the transition. The generation ability of coumarins of this class manifests itself only in the presence of the strongest donor substituents (for example, Et2N and OH) in position 7, and sufficiently strong acceptors in positions 6′ and 7′. Lasing was obtained in the spectral region of 730 –740 nm on dyes – benzopyrylium derivatives.
subject: Laser Physics
  topic: section
subject: coumarins
  topic: keywords
subject: benzopyrylium derivatives
  topic: keywords
subject: absorption spectra
  topic: keywords
subject: molecular structure
  topic: keywords
subject: bichromophores
  topic: keywords
subject: generation characteristics
  topic: keywords
creator: Slavamir S. Anufrik
creator: Vikentiy V. Tarkovsky
creator: Sergey N. Anuchin
rights: Copyright (c) 2022 Journal of the Belarusian State University. Physics
date: 2022-06-06
publication date: 2022-06-06
starting page: 19
ending page: 25
doi: 10.33581/2520-2243-2022-2-19-25

Formation of epitaxial 3C-SiC layers on Si by rapid vacuum thermal processing
type: item
description: The results of a study of the structure and phase composition of epitaxial layers of silicon carbide (SiC) formed on silicon substrate with orientation (100) under rapid vacuum thermal processing are presented. Planar-view transmission electron microscopy investigation revealed the formation of epitaxial layers of cubic polytype SiC (3C-SiC) on silicon in the process of carbidisation at 1100 °C during 30 s, using a gas mixture of propane (10 %) and argon (90 %) as a carbon source. The formation of a monocrystalline 3C-SiC with polycrystalline inclusions and twins on all possible planes {111} was found. A rather narrow band of 793 cm–1 transverse optical phonon mode SiC on Raman spectra confirms the formation of a cubic polytype SiC. It is noted that the presence of a 180 cm–1 spectral line and a 793 cm–1 half-width band on Raman spectra indicate the presence of deformation defects in SiC.
subject: Semiconductor Physics and Engineering
  topic: section
subject: epitaxial structures SiC/Si
  topic: keywords
subject: vacuum carbidisation
  topic: keywords
subject: rapid thermal processing
  topic: keywords
subject: thin films
  topic: keywords
creator: Mikhail V. Lobanok
creator: Stanislau L. Prakopyeu
creator: Maksim A. Makhavikou
creator: Olga V. Korolik
creator: Peter I. Gaiduk
rights: Copyright (c) 2022 Journal of the Belarusian State University. Physics
date: 2022-06-08
publication date: 2022-06-08
starting page: 79
ending page: 86
doi: 10.33581/2520-2243-2022-2-79-86

The regional nanosatellite constellation modelling formation by a piggyback launch from different spaceports
type: item
description: The roadmap for constructing a regional nanosatellite constellation using the piggyback launch according to Chinese provider information has developed. For nanosatellite constellation formation to a specific purpose, it is necessary to analyse existing constellation operated similar tasks. Therefore, the software module for the Spire Global constellation orbital construction analysis was developed. The construction of Spire Global nanosatellites constellation based on orbital parameters database in the two-line element set format, satellite constellation databases and the developer site was analysed. A launch from the International Space Station and a piggyback launch were used for constellation formation. Nanosatellite deployment schemes, orbital parameters and flight parameters are investigated launches from the Taiyuan and Jiuquan Satellite Launch Centers with orbit inclination about 90°, that best correspond to the passes over Minsk (ϕ = 53°54′27″ N, λ = 27°33′52″ E) are analysed. The method of nanosatellite orbit preflight prediction at a passing launch has been developed. It involves a finding the nanosatellite state vector in the first flight day and at the time of constellation mission operate start. The launch time, satellite launch center coordinates, launch vehicle type, orbit inclination and altitude (period) are used in the method. In addition, the launch history and the satellite motion dynamics analysis on similar orbits is carried out. It was found that five launches are enough to organise a regional nanosatellite constellation with average radio visibility interruption time of at least 36 min with a maximum value of 85 min.
subject: Astrophysics
  topic: section
subject: nanosatellite constellation
  topic: keywords
subject: piggyback launch
  topic: keywords
subject: pre-flight orbit prediction
  topic: keywords
creator: Alexander A. Spiridonov
creator: Vasilina S. Baranova
creator: Vladimir A. Saetchnikov
creator: Dmitrii V. Ushakov
rights: Copyright (c) 2022 Journal of the Belarusian State University. Physics
date: 2022-06-22
publication date: 2022-06-22
starting page: 50
ending page: 59
doi: 10.33581/2520-2243-2022-2-50-59

Uni- and multivariate calibration of tempe­rature from the neodymium fluorescence spectra in nanocrystals of yttrium-gadolinium oxide and yttrium-gadolinium garnet
type: item
description: The use of neodymium-doped nanocrystalline powders of yttrium-gadolinium oxide and yttrium gadolinium garnet to increase the sensitivity of local fluorescent optical temperature sensors is considered. Based on the temperature dependences of the neodymium fluorescence spectra in this powders, univariate (using fluorescence intensity ratio from thermally coupled energy levels of the activator) and multivariate (using the partial least squares method) calibration models are developed. When using the spectral range 860 – 950 nm falling into the first biological transparency window (700 – 980 nm), both calibration models have a standard deviation of about 10 % and are comparable in accuracy. The spectral variables selection by searching combination moving window in the multivariate model made it possible to reduce the root mean square error for yttrium-gadolinium oxide by more than 12 times (from 9.8 to 0.8 °C), and for yttrium-gadolinium garnet by more than 2 times(from 8.7 to 4.0 °С). The result obtained indicatesthe proposed neodymium-doped nanocrystalline powders and multivariate methods of calibration can be used to localise areas with febrile temperatures for biological and medical purposes.
subject: Optics and Spectroscopy
  topic: section
subject: fluorescence
  topic: keywords
subject: nanocrystals
  topic: keywords
subject: multivariate calibration
  topic: keywords
subject: partial least squares method
  topic: keywords
subject: fluorescence intensity ratio method
  topic: keywords
creator: Mikhail A. Khodasevich
creator: Darya A. Borisevich
creator: Vladimir A. Aseev
creator: Natalia K. Kuzmenko
creator: Irina M. Sevastianova
rights: Copyright (c) 2022 Journal of the Belarusian State University. Physics
date: 2022-06-03
publication date: 2022-06-03
starting page: 12
ending page: 18
doi: 10.33581/2520-2243-2022-2-12-18

Structure formation and peculiarities of crystallisation of lead-free tin – zinc alloys obtained by rapid solidification
type: item
description: The results of the study of the microstructure of lead-free alloys of the tin – zinc system obtained by rapid solidification at a cooling rate of at least 105 K/s are presented. In tin and zinc alloys with concentrations of 1.2–2.0 wt. % Zn and 1.5 wt. % Sn, respectively, during rapidly cooling of the melt, the alloying element is captured. The formed solid solutions are supersaturated and at room temperature disintegrate according to the mechanism of formation and growth of nuclei of a new phase. The average size of zinc and tin precipitates after holding the foil for two days does not exceed 0.5 μm. Melts of compositions Sn – 4.4–15.0 wt. % Zn after rapidly cooling are supercooled and supersaturated by two components and experience spinodal decomposition (stratification) followed by the formation of supersaturated solid solutions based on tin and zinc, which disintegrate at room temperature. The average size of zinc precipitates in non-equilibrium eutectic does not exceed 2 μm. In rapid solidificated foils of alloys containing 50–80 wt. % Zn, a two-phase structure is formed from solid solutions based on tin and zinc. The average size of tin precipitates does not exceed 1 μm. As the crystallisation front moves away from the contact surface of the foil with the surface of the mold, the tin particles become larger and the specific surface of the interphase boundary decreases.
subject: Condensed State Physics
  topic: section
subject: tin
  topic: keywords
subject: zinc
  topic: keywords
subject: supersaturated solution
  topic: keywords
subject: microstructure
  topic: keywords
subject: eutectic
  topic: keywords
subject: rapid solidified alloys
  topic: keywords
creator: Denis A. Zernitsa
creator: Vasili G. Shepelevich
rights: Copyright (c) 2022 Journal of the Belarusian State University. Physics
date: 2022-10-31
publication date: 2022-10-31
starting page: 48
ending page: 55
doi: 10.33581/2520-2243-2022-3-48-55

«Uncanny valley» effect in holographic image transmission
type: item
description: The quality of computer-synthesised images is continuously improving, increasing in the volume of files representing them. It is noticed that passing from simple schematic images to increasingly complex ones, their perception goes through different stages. If initially the complication of the image and its approximation to the real image of a person makes a favourable impression, then there comes a moment of fright and rejection. Masahiro Mori called it the «uncanny valley» effect. Since then, all new technologies for presenting human images have been tested in order to avoid this effect. This effect should be treated especially carefully when compressing and then restoring complex images. This paper shows the position relative to the «uncanny valley» of the reconstructed 3D images, reconstructed by a hologram synthesised and transmitted with compression over the communication channel in accordance with patent RU2707582C1.
subject: Optics and Spectroscopy
  topic: section
subject: holography
  topic: keywords
subject: holographic information
  topic: keywords
subject: 3D object
  topic: keywords
subject: «uncanny valley» effect
  topic: keywords
subject: information transfer
  topic: keywords
subject: 3D augmented reality
  topic: keywords
subject: 3D image quality
  topic: keywords
creator: Sergey A. Shoydin
creator: Artem L. Pazoev
rights: Copyright (c) 2022 Journal of the Belarusian State University. Physics
date: 2022-10-20
publication date: 2022-10-20
starting page: 4
ending page: 9
doi: 10.33581/2520-2243-2022-3-4-9

Analysis of the reciprocal lattice of crystals with non-primitive Bravais cells
type: item
description: The aim of the work was proof the independence of the reciprocal lattice of a crystal from the choice of a cell in its direct lattice. The object of analysis was the dependence of the position of reciprocal lattice cell sites and direct lattice parameters based on quadratic formulas, as well as the structural amplitudes («weights» of reciprocal lattice sites) for crystals with non-primitive cells. The following tasks were solved: choice of a Bravais rapper with a P-type cell in a crystal with I-, F- and C-type cells; construction of direct and reciprocal metric tensors for centered cells of a direct lattice and for P-type cells of crystal lattices; establishment of the transition rule from the HKL indices of the nodes of the reciprocal lattice with the selected P-cell to the hkl indices of the same nodes for non-primitive cells based on quadratic formulas; determining a connection between HKL and hkl indices using metric tensors; analysis of the results obtained by two different methods (based on quadratic formulas and using metric tensors); proof, that in the reciprocal lattice of crystals with non-primitive cells, the nodes that correspond to «fading» reflections are actually absent in the reciprocal lattice. The research results are addressed to specialists in the field of crystal physics and represent a rigorous proof that fills a gap in the mathematical apparatus of the kinetic theory of scattering by crystals with non-primitive Bravais cells. It allows eliminating redundant statements about the «extinction» of part of the reflexes that are not recorded on X-rays due to their real absence from scientific circulation.
subject: Condensed State Physics
  topic: section
subject: direct lattice
  topic: keywords
subject: reciprocal lattice
  topic: keywords
subject: supercell
  topic: keywords
subject: crystallographic coordinate system
  topic: keywords
subject: crystallophysical coordinate system
  topic: keywords
subject: metric tensor
  topic: keywords
subject: structural amplitude
  topic: keywords
creator: Valery A. Liopo
creator: Irena A. Liaushuk
rights: Copyright (c) 2022 Journal of the Belarusian State University. Physics
date: 2022-10-17
publication date: 2022-10-17
starting page: 68
ending page: 80
doi: 10.33581/2520-2243-2022-3-68-80

Equivalent circuits of FeCoZr-alloy nanoparticles deposited into Al2O3 and PZT dielectric matrices nanogranular composite films
type: item
description: The paper presents equivalent substitution circuits (ESCs) describing nanogranular composite films (Fe0.45Cо0.45Zr0.10)x(Al2O3)1 – x and (Fe0.45Cо0.45Zr0.10)x(PZT)1 – x with a concentration of metal-containing granules in the range 0.3 < х < 0.8. Films of 2–7 μm thick were obtained by ion-beam sputtering of composite targets in pure argon or in Ar – O2 mixture, followed by stepwise (with a step of 25 K) isochronous (15 min) annealing in air in the temperature range of 398 – 873 K. Deposition of nanocomposites in an oxygen-containing atmosphere or subsequent annealing in air led to the formation of nanoparticles with a core – shell structure consisting of Fe0.45Cо0.45Zr0.10 metallic alloy cores coated with shells of native iron and cobalt oxides (FeO, Fe3O4, Fe2O3, CoO). It has been established that when such shells contain semiconductor-type iron oxides (like FeO and Fe3O4) the frequency dependences of the total impedance Z (f, T) of nanocomposites can be described using ESCs containing two resonant RCL-circuits, that is accompanied by a positive phase shift of the current relative to the applied bias voltage (the so-called negative capacitance effect). The prevailing of dielectric-like oxides (Fe2O3) in shells around metallic cores leads to ESCs either with one resonant RCL-circuit or without it at all. This results in disappearing of the negative capacitance effect when usual capacitive-like behaviour of nanocomposite behaviour is observed. It is shown that if we construct ESCs for nanocomposites with different ratios of the metallic (FeCoZr) and dielectric (Al2O3, PZT) components, it is possible to describe the Z (f, T) dependences for every circuit elements (R, C, L) corresponding both to individual phase components in nanocomposites including intrinsic semiconductor- or dielectric-like iron and cobalt oxides in shells around metallic cores.
subject: Nanomaterials and Nanotechnologies
  topic: section
subject: nanogranular composites
  topic: keywords
subject: core – shell nanoparticles
  topic: keywords
subject: equivalent substitution circuits
  topic: keywords
subject: negative capacitance effect
  topic: keywords
creator: Andrei V. Larkin
creator: Alexander K. Fedotov
rights: Copyright (c) 2022 Journal of the Belarusian State University. Physics
date: 2022-10-27
publication date: 2022-10-27
starting page: 104
ending page: 112
doi: 10.33581/2520-2243-2022-3-104-112

Electrophysical characteristics of power MOSFETs additionally implanted with nitrogen ions
type: item
description: The electrical characteristics of power MOSFETs additionally implanted with nitrogen ions have been studied. Ion implantation of nitrogen was carried out through a protective oxide of 23 nm thickness with energies of 20 and 40 keV and doses of 1 ⋅ 1013‒5 ⋅ 1014 cm–2. Rapid thermal annealing was carried out at temperature of 900 or 1000 °C for 15 s. It has been established that nitridisation of the gate dielectric makes it possible to reduce the noise of the gate leakage currents and their dispersion. In the direct order of heat treatment (first rapid thermal annealing, and then the removal of the protective oxide), for samples prepared with an additional operation of nitrogen ion implantation, there is an increase in the threshold voltage compared to control samples. The capacitance of the gate dielectric in the case of implantation of nitrogen ions in the direct order of heat treatment is less than for control samples. It has been established that in the direct order of rapid thermal annealing, the doses of nitrogen ion implantation do not cause significant changes in the maximum value of the current-voltage slope. At the same time, in all studied cases, there is a shift in the maximum value of the current-voltage slope towards higher gate voltages. In the reverse order of heat treatment (first the removal of the protective oxide, and then rapid thermal annealing), there are no significant differences in the value of the threshold voltage for the samples created with additional nitrogen implantation and the control ones. The maximum value of the current-voltage slope also does not experience significant changes. It is shown that in the voltage range from – 0.15 to 0 V, the drain current of nitrogen-implanted samples manufactured using the direct order of heat treatment is higher than for control samples, and the drain current of nitrogen-implanted samples obtained with the reverse order of heat treatment it is lower compared to control samples. Results are explaine…
subject: Semiconductor Physics and Engineering
  topic: section
subject: gate dielectric
  topic: keywords
subject: ion implantation
  topic: keywords
subject: nitrogen ions
  topic: keywords
subject: power MOSFETs
  topic: keywords
creator: Vladimir B. Odzaev
creator: Aliaksandr N. Pyatlitski
creator: Uladislau S. Prasalovich
creator: Natalya S. Kovalchuk
creator: Yaroslav A. Soloviev
creator: Dmitry V. Shestovski
creator: Valentin Yu. Yavid
creator: Yuri N. Yankovski
rights: Copyright (c) 2022 Journal of the Belarusian State University. Physics
date: 2022-09-29
publication date: 2022-09-29
starting page: 81
ending page: 92
doi: 10.33581/2520-2243-2022-3-81-92

Thermal and thermoelectric properties of ceramics based on zinc oxide alloyed with iron
type: item
description: In this work, we study the effect of adding iron oxides FeO and Fe2O3 in a ratio of 1 : 9 on the thermal and thermoelectric characteristics of ceramics based on zinc oxide ZnO. The samples themselves were made in two stages based on the ceramic technology of sintering powder mixtures in an open atmosphere. Thermal conductivity studies point to the dominant contribution of lattice thermal conductivity at room temperature. The decrease in thermal conductivity as a result of alloying is due to an increase in phonon scattering at point defects introduced into the ZnO lattice (due to the replacement of zinc ions by iron ions) and at grain boundaries (due to microstructure refinement), as well as an increase in porosity (a decrease in density) and the formation of particles of an additional ZnFe2O4 ferrite phase. Alloying wit iron and the accompanying change in the structure of ceramics (decrease in grain size, increase in porosity, precipitation of the ferrite phase) leads to an increase in the thermoelectric figure of merit ZT by 2 times (due to a decrease in electrical resistivity and thermal conductivity with a relatively small decrease in the thermoelectric coefficient). The results obtained can be used to fabricate ZnO-based ceramics with optimal thermoelectric characteristics.
subject: Condensed State Physics
  topic: section
subject: ceramics
  topic: keywords
subject: zinc oxide
  topic: keywords
subject: density
  topic: keywords
subject: thermal conductivity
  topic: keywords
subject: phonon scattering
  topic: keywords
subject: thermoelectric figure of merit
  topic: keywords
creator: Aliaksei V. Pashkevich
creator: Ludmila A. Bliznyuk
creator: Alexander K. Fedotov
creator: Vladimir V. Khovaylo
creator: Andrei A. Kharchanka
creator: Vera V. Fedotova
rights: Copyright (c) 2022 Journal of the Belarusian State University. Physics
date: 2022-10-10
publication date: 2022-10-10
starting page: 56
ending page: 67
doi: 10.33581/2520-2243-2022-3-56-67

Influence of high-temperature ion irradiation on nanostructured TiAlN coatings
type: item
description: Nanostructured TiAlN coatings were formed on AISI 304 stainless steel substrates by reactive magnetron sputtering. The studied TiAlN coatings were irradiated with Ar+ ions with an energy of 200 keV in the fluence range from 2.5 ⋅ 1016 to 2.0 ⋅ 1017 ion per 1 cm2 at a temperature of 480 °C. Using energy-dispersive X-ray spectroscopy, scanning electron microscopy and X-ray diffraction phase analysis, the elemental composition, structural-phase state and morphology of the initial and irradiated coatings were studied. Nanoindentation of the obtained structures was carried out according to the method of Oliver and Pharr, the nanohardness (Н) and Young’s modulus (E) were determined, and the impact strength of the coatings under study was calculated as the H/E∗ ratio. The formation of a single-phase structure of the (Ti, Al)N solid solution in the coatings initial state has been detected. The effect of selective sputtering of the lightest component – nitrogen – from the coatings was found. Up to an irradiation fluence of 1.0 ⋅ 1017 ion per 1 cm2, no significant changes were revealed in the structural-phase state of the coatings. When irradiated with a fluence of 2.5 ⋅ 1016 ion per 1 cm2, an improvement in the TiAlN coatings strength properties complex was observed. It has been found that nanostructured TiAlN coatings are radiation-resistant up to an irradiation fluence of 2.0 ⋅ 1017 ion per 1 cm2, at which the onset of segregation of the (Ti, Al)N solid solution as the main phase of the coatings and blistering effect is observed.
subject: Condensed State Physics
  topic: section
subject: nanostructured TiAlN coatings
  topic: keywords
subject: structural-phase state
  topic: keywords
subject: tribomechanical properties
  topic: keywords
subject: nanoindentation
  topic: keywords
subject: radiation tolerance
  topic: keywords
creator: Stanislav V. Konstantinov
creator: Fadei F. Komarov
creator: Igor V. Chizhov
creator: Jerzy Żuk
creator: Valery A. Zaikov
rights: Copyright (c) 2022 Journal of the Belarusian State University. Physics
date: 2022-09-26
publication date: 2022-09-26
starting page: 39
ending page: 47
doi: 10.33581/2520-2243-2022-3-39-47

Classification of Norway spruce drying states on the basis of reflection spectra
type: item
description: The article is devoted to the development of a method for classifying the reflection spectra of spruce needles of different health categories and assessing the quality of the classification. Such health categories of spruces have been chosen that include the initial stages of drying out, which is essential for early detection of disease foci, but makes it difficult to classify according to visual criteria by means of remote sensing of the Earth. An algorithm for untrained classification and visualisation of spectral data based on correlation and cluster analysis is proposed. The reflection spectra of spruce needles obtained under laboratory conditions were studied and the results were interpreted using the developed software. The analysis of various combinations of parameters within the proposed algorithm, as well as combinations of individual components of the algorithm with known classification methods, made it possible to determine the most effective combination of parameters and classification methods (projection of spectra into the space of principal components, elimination of the influence of the first principal component on spectra, the Ward cluster linking metric and the standardised Euclidean metric for calculating the spectral distance) for detection of different stages of spruce disease. Its use to made it possible to increase the F-score classification quality indicator for the 2nd health category (the most important category for the task of detecting drying in the early stages) up to 70.59 %.
subject: Optics and Spectroscopy
  topic: section
subject: reflection spectrum
  topic: keywords
subject: spruce needles
  topic: keywords
subject: drying
  topic: keywords
subject: principal component analysis
  topic: keywords
subject: classification
  topic: keywords
creator: Anton O. Martinov
rights: Copyright (c) 2022 Journal of the Belarusian State University. Physics
date: 2022-09-26
publication date: 2022-09-26
starting page: 26
ending page: 38
doi: 10.33581/2520-2243-2022-3-26-38

Liquid crystalʼs photoalignment for formation of phase profiles via geometric phase distribution
type: item
description: Basic understandings on the concept of geometric phase, also known as Pancharatnam – Berry phase, and its application to creation of photonic liquid crystal devices as thin-films of photoaligned nematic liquid crystals are presented. The significance of the strong azimuthal anchoring energy and the role of birefringence in liquid crystal photoalignment layer for formation of geometric phase gradients are shown. The dependence of phase retardation of circular polarised light passing through the half-wave phase plate on the azimuthal angle of the plate orientation is explained in details, as it gives ground to formation of geometric phase distribution of optical liquid crystal devices, working in circular polarised light. The effective refractive index is introduced for characterisation of the optical properties of linear periodic liquid crystal’s structure that forms profile of geometric phase surface. The successful implementations of photonic liquid crystal devices (polarisation diffraction grating, annular diffraction grating, q-plate, q-plate with a phase core) are analysed in terms of geometric phase distributions and the corresponding equations of profile of the phase surfaces that ensure functioning of the devices are presented.
subject: Optics and Spectroscopy
  topic: section
subject: phase profile
  topic: keywords
subject: geometric phase
  topic: keywords
subject: Pancharatnam – Berry phase
  topic: keywords
subject: photoalignment
  topic: keywords
subject: liquid crystals
  topic: keywords
subject: liquid crystal photonics
  topic: keywords
creator: Veranika Yu. Stanevich
creator: Alexander A. Muravsky
rights: Copyright (c) 2022 Journal of the Belarusian State University. Physics
date: 2022-09-26
publication date: 2022-09-26
starting page: 10
ending page: 25
doi: 10.33581/2520-2243-2022-3-10-25

Estimation of the contribution of scattered ionising radiation to the dosimeter readings during measurements inside a low-background chamber
type: item
description: The article evaluates the contribution of ionising gamma radiation scattered by structural materials when measuring the dose rate in a low-background chamber. The contribution of scattered radiation to the total dose rate was estimated using Monte Carlo simulations. A model of a low-background camera and a BDKG-05K dosimeter was created in the computer program Fluka. In addition, a model of a point source of 137Cs gamma radiation was placed in the low-background chamber. The fraction of scattered radiation was calculated by comparing the dosimeter readings when measuring the dose rate inside the low-background chamber with the reference model (the dosimeter model is placed together with the source in a vacuum, as a result, scattered radiation is completely absent). The calculation was carried out for two positions of the dosimeter relative to the source (30 and 100 cm). It was found that the contribution of scattered radiation to the dose rate reaches 38 % (distance from the source to the detector is 100 cm). To minimise the contribution of scattered radiation to the readings of the dosimeter, a design in the form of a collimator, inside which the source is located, was considered. Additionally, the work investigated the dependence of the dose rate formed by the scattered radiation on the design features of the collimator. It was found that the use of a collimator makes it possible to reduce the contribution of scattered radiation to 3 %. The aim of the work was to calculate the optimal design of the collimator, in which the contribution of scattered radiation to the total dose rate will be minimal. The results of the work will be used to create a prototype of a low-background camera and an optimised collimator.
subject: Physics of Radiation Dosimetry
  topic: section
subject: Monte Carlo modelling
  topic: keywords
subject: Fluka
  topic: keywords
subject: low-background chamber
  topic: keywords
subject: ionising radiation
  topic: keywords
subject: dosimetry
  topic: keywords
subject: scattering radiation
  topic: keywords
creator: Aleksei A. Zaharadniuk
creator: Roman V. Lukashevich
rights: Copyright (c) 2022 Journal of the Belarusian State University. Physics
date: 2022-01-27
publication date: 2022-01-27
starting page: 98
ending page: 108
doi: 10.33581/2520-2243-2022-1-98-108

Determination of the Bessel light beam cone parameter by Fourier analysis of the diametral distribution of the intensity
type: item
description: Power spectral density (PSD) of the intensity distribution of an ideal Bessel light beam (BLB) expressions are obtained. It is shown that the PSD of the intensity distribution of an ideal BLB is limited and the upper boundary of the PSD is equal to the doubled cone parameter (the product of the wave number and the sine of the half angle of the cone of wave vectors), and the number of zeros in the PSD of an ideal BLB located in the interval from zero frequency to the upper boundary of the spectrum, is equal to the order of the beam. A technique is proposed for estimating the cone parameter of BLBs by analysing the PSD estimates of diametral distributions – one-dimensional intensity distributions obtained in the transverse plane of the beam along a line passing through the beam axis from transverse two-dimensional BLB intensity distributions recorded in the form of digital computer images. The influence of clipping (the end of the distribution at the boundary of the sensitive sensor), Gaussian and cosine modulations of the diametral distribution on the shape of the spectrum and, in case of clipping, the error in the cone parameter estimation using the proposed method is investigated. The technique is tested on the example of the analysis of experimental BLBs of different orders (BLBm, m = 0, 1, 2). The proposed technique can be used to assess the quality parameters of the BLB. The results of the analysis of the influence of cosine modulation on the shape of the PSD can be used to assess the magnitude of the rounding of the apex of the axicon forming the BLB for control the quality of the axicon manufacturing.
subject: Optics and Spectroscopy
  topic: section
subject: Bessel light beam
  topic: keywords
subject: cone angle
  topic: keywords
subject: cone parameter
  topic: keywords
subject: power spectral density
  topic: keywords
creator: Anatol A. Ryzhevich
creator: Igor V. Balykin
rights: Copyright (c) 2022 Journal of the Belarusian State University. Physics
date: 2022-01-27
publication date: 2022-01-27
starting page: 20
ending page: 34
doi: 10.33581/2520-2243-2022-1-20-34

Method for studying the photostability of solar cells based on organic-inorganic perovskites using a confocal spectrometer
type: item
description: A method for studying photosensitive structures using the example of studying the photodegradation and dark recovery of organic-inorganic perovskite solar cells is present. The method is based on the use of a confocal spectrometer to measure Raman spectra, photo- and electroluminescence spectra and kinetics, the kinetics of the short-circuit current and the open-circuit voltage under local exposure to monochromatic radiation. Raman spectra make it possible to establish the presence or absence of secondary phases, the formation of which is possible in photosensitive layers under the influence of light. The photoluminescence spectra enable to reveal the single-phase nature of the object under study. Mapping the intensity and position of the center of mass of the photoluminescence band in the plane of the object makes it possible to judge the spatial arrangement of the centers of non-radiative recombination of charge carriers, the distribution of the regions with the highest and lowest efficiency of the extraction of charge carriers by transport-acceptor layers and the spatial homogeneity of the chemical composition. Comparison of the electroluminescence spectra before and after light exposure allows revealing the formation of non-radiative recombination centers in the photoabsorbing layer and at interfaces with the transport layers. Analysis of the kinetics of changes in the parameters of the photoluminescence band obtained by measuring the short-circuit current and the open-circuit voltage makes it possible to establish the dominant photoinduced processes leading to a change in the intensity of the photoluminescence band.
subject: Research Instruments and Methods
  topic: section
subject: confocal spectrometer
  topic: keywords
subject: luminescence
  topic: keywords
subject: Raman scattering
  topic: keywords
subject: organic-inorganic perovskites
  topic: keywords
subject: perovskite solar cells
  topic: keywords
subject: method for studying photostability
  topic: keywords
creator: Natallia S. Mahon
creator: Olga V. Korolik
creator: Alexander V. Mazanik
rights: Copyright (c) 2022 Journal of the Belarusian State University. Physics
date: 2022-01-27
publication date: 2022-01-27
starting page: 88
ending page: 97
doi: 10.33581/2520-2243-2022-1-88-97

Analytical diagonalisation of the Hamiltonian of the quantum Rabi model in the Coulomb gauge
type: item
description: In the present paper we investigate the approximate analytical diagonalisation of the Hamiltonian of the quantum Rabi model written in the Coulomb gauge and taking into account the gauge invariance of the system. It is shown that the Hamiltonian of the model can be diagonalised with high accuracy on the basis of a unitary operator of the gauge transformation utilising a simple basis set of state vectors. It is essential that the obtained approximate expressions do not depend on the variational parameters and are valid within the whole range of the parameter values. The zeroth-order approximation and uniformly available approximation are derived for the eigenstates of the system, and their comparison with the results of the numerical simulation is elaborated. The second-order correction to the zeroth-order approximation is deduced and its contribution to the energy of the system is estimated. The obtained results could be useful for description of the evolution of the quantum Rabi model as well as for investigation of systems of two-level atoms in the resonant quantum field.
subject: Theoretical Physics
  topic: section
subject: quantum Rabi model
  topic: keywords
subject: operator method
  topic: keywords
subject: two-level system
  topic: keywords
subject: quantum field
  topic: keywords
subject: resonance
  topic: keywords
subject: gauge invariance
  topic: keywords
creator: Aliaksandr U. Leonau
creator: Ilya D. Feranchuk
rights: Copyright (c) 2022 Journal of the Belarusian State University. Physics
date: 2022-01-27
publication date: 2022-01-27
starting page: 44
ending page: 51
doi: 10.33581/2520-2243-2022-1-44-51

Charging properties of thin gate dielectrics, obtained by the method of rapid thermal processing
type: item
description: The charge properties of thin dielectrics, obtained by rapid thermal processing (RTP), and their interfaces with silicon for MOS transistors are investigated. The production of insulator layers was carried out by a two- or three-stage RTP with photon processing regimes similar for each stage (duration – 12 s, maximum temperature – 1250 °C). After the third stage of RTP in a nitrogen atmosphere of the gate oxides, obtained by a two-stage process in oxygen atmosphere, the defects responsible for local charge centers are partially eliminated. There is also an increase in the relative value of the surface potential by an average of 100 relative units. The elimination of defects is a consequence of the rearrangement of the structure of the dielectric, its interface with silicon, and the diffusion of oxygen and silicon atoms along the interface of the insulator layer. For samples obtained by a two-stage RTP in an oxygen atmosphere and subjected to the third stage of processing in a forming gas, there is an almost complete elimination of local charge centers and an increase in the relative value of the surface potential by an average of 300 relative units. In this case, in addition to the processes occurring during the treatment of SiO2 by the RTP method in an nitrogen atmosphere, the liquidation of charge centers is a consequence of the passivation of defects by hydrogen atoms.
subject: Semiconductor Physics and Engineering
  topic: section
subject: gate dielectric
  topic: keywords
subject: rapid thermal processing
  topic: keywords
subject: three-stage process
  topic: keywords
subject: surface potential
  topic: keywords
creator: Natalya S. Kovalchuk
creator: Yuliya A. Marudo
creator: Anna A. Omelchenko
creator: Uladzimir A. Pilipenka
creator: Vitali A. Saladukha
creator: Sergey A. Demidovich
creator: Vladimir V. Kolos
creator: Victor M. Anishchik
creator: Viktar A. Filipenia
creator: Dmitry V. Shestovski
rights: Copyright (c) 2022 Journal of the Belarusian State University. Physics
date: 2022-01-28
publication date: 2022-01-28
starting page: 80
ending page: 87
doi: 10.33581/2520-2243-2022-1-80-87

Hydrogen-phase naklep as a result of single isothermal hydride transformations
type: item
description: Hydrogen treatment of metallic materials is a promising area of controlled hydrogen action on metals and alloys in order to impart special properties to them. In this work, the changes in the mechanical properties of palladium during single hydride transformations, which are initiated in the initially non-nakleped palladium hydride, have been experimentally studied. Were investigated wire palladium samples with a purity of 99.98 %, a diameter of 0.5 mm and a length of 165 mm. Samples for research were preliminarily subjected to hydrogen treatment, and then mechanical tests were carried out. The mechanical properties of non-nakleped palladium hydride are presented. Hydrogen-phase naklep of palladium during hydrogen treatment has been studied. It is shown that palladium hydride is a plastic material with low strength characteristics. During the reverse hydride transformation, the hydrogen phase naklep of palladium develops. Experimental facts of the appearance of hydrogen-phase naklep during the interaction of hydrogen with other metals and alloys are discussed.
subject: Condensed State Physics
  topic: section
subject: hydride transformation
  topic: keywords
subject: palladium – hydrogen system
  topic: keywords
subject: palladium hydride
  topic: keywords
subject: mechanical properties
  topic: keywords
subject: hydrogen treatment
  topic: keywords
subject: hydrogen-phase naklep
  topic: keywords
creator: Gregory I. Zhirov
creator: Mariya V. Goltsova
rights: Copyright (c) 2022 Journal of the Belarusian State University. Physics
date: 2022-01-27
publication date: 2022-01-27
starting page: 65
ending page: 74
doi: 10.33581/2520-2243-2022-1-65-74

The structure of rapidly solidified foil of Al – Bi alloys
type: item
description: The results of study of the microstructure and texture of aluminum alloys, containing 0.12 and 0.25 at. % Bi, obtained with high-speed solidification, are presented (melt cooling rate liquid – not less 105 K /s). Texture (111) aluminum is formed in the rapidly solidified foils of investigated alloys and it is conserved under annealing at 523 K during 2 h. The average chord of bismuth sections does not exceed 0.05 µm. As the crystallisation front moves from surface A contacted with crystalliser to the surface B, the average size of dispersed bismuth particles increases. Foils of the alloys dissolve in water at room temperature actively forming hydrogen bubbles in vessel with water, white powder of aluminum oxide in an amorphous state and bismuth precipitations. Isotermical annealing of foils at 573 K for 5 h causes a change in distribution of chords in size groups and increases their average value. After the annealing bismuth particles are localised on low- and high-angle boundaries. The rapidly solidified foils of Al – Bi system can be used to produced hydrogen, aluminum oxide powder and create technical devices using hydrogen.
subject: Condensed State Physics
  topic: section
subject: generation of hydrogen
  topic: keywords
subject: aluminum alloy
  topic: keywords
subject: water
  topic: keywords
subject: texture
  topic: keywords
subject: high-speed solidification
  topic: keywords
subject: dispersive particles of bismuth
  topic: keywords
creator: Vasili G. Shepelevich
rights: Copyright (c) 2022 Journal of the Belarusian State University. Physics
date: 2022-01-28
publication date: 2022-01-28
starting page: 75
ending page: 79
doi: 10.33581/2520-2243-2022-1-75-79

Recording the dynamic polarisation gratings in pure nematic liquid crystal
type: item
description: We report on experimental realisation of polarisation dynamic gratings recording in pure nematic liquid crystal. This work is devoted to the experimental implementation of writing polarisation dynamic gratings in a pure nematic liquid crystal. The registration mechanism is based on the photorefractive effect in a cell filled with a pure nematic crystal under the action of an applied constant electric field. This phenomenon does not require the presence of photoexcited charge carriers in the liquid crystal and is explained by the extremely high anisotropy of the liquid crystal. The article provides an elementary theoretical model of this process. The dependences of the grating writing process on the spatial frequency of the interference field and the intensity of the recording beams are investigated. It was found that the spatial grating does not coincide with the interference field – the response of the medium is non-local. However, we do not associate this property with that in photorefractive crystals. In our case, a mechanism of purely geometric mismatch is more likely due to the peculiarity of the recording mechanism. One of the fundamental properties of the described processes is their independence from the wavelength of the recording radiation, which confirms the model of the recording mechanism we have chosen.
subject: Optics and Spectroscopy
  topic: section
subject: liquid crystals
  topic: keywords
subject: photorefractivety
  topic: keywords
subject: holography
  topic: keywords
creator: Sergei S. Slussarenko
creator: Elena A. Melnikova
creator: Alexei L. Tolstik
rights: Copyright (c) 2022 Journal of the Belarusian State University. Physics
date: 2022-02-01
publication date: 2022-02-01
starting page: 14
ending page: 19
doi: 10.33581/2520-2243-2022-1-14-19

Determination of the parameters of two-beam laser splitting of silicate glasses using regression and neural network models
type: item
description: The current work takes the results of the numerical experiment implemented in the Ansys finite element analysis program to create the neural network and regression models of two-beam laser splitting of silicate glasses. The regression models of two-beam laser glass cutting have been obtained in the DesignXplorer module of Ansys Workbench using a face-centered version of the central composite design. The processing speed, the parameters of laser beams, the glass plate thickness, and the distance between the laser radiation and the refrigerant affected zones were used as variable factors. The maximum temperatures and thermoelastic tensile stresses in the laser processing area were used as responses. The artificial neural networks have been constructed and trained using the TensorFlow package. The results of determining the maximum temperatures and thermoelastic stresses in the laser treatment area using the neural network and regression models have been compared.
subject: Laser Physics
  topic: section
subject: laser splitting
  topic: keywords
subject: glass plate
  topic: keywords
subject: neural network
  topic: keywords
subject: Ansys
  topic: keywords
creator: Yuri V. Nikitjuk
creator: Anatoly N. Serdyukov
creator: Igor Y. Aushev
rights: Copyright (c) 2022 Journal of the Belarusian State University. Physics
date: 2022-02-03
publication date: 2022-02-03
starting page: 35
ending page: 43
doi: 10.33581/2520-2243-2022-1-35-43

Transport properties of two-component radium – halogen dilute gas media
type: item
description: Based on state-of-the-art ab initio potential energy functions and classical kinetic theory, some transport properties (diffusion, viscosity and thermal conductivity coefficients) of two-component dilute gas media of radium and halogen (F, Cl, Br, I) atoms were predicted as functions of the translation temperature up to 3000 K. Calculations were performed by sequential analytical and (or) numerical computations of deflection angle, cross-section and collision integrals. A detailed methodology for the calculation of the transport properties using the Morse potential was developed. Some numerical difficulties arising due to the singularity of the integrands and discontinuous character of the variable of integration are considered. The dependence of transport properties on isotope mass is also shown. Possible errors introduced by using the model Morse potential function instead of the real potential for the interaction between atoms are estimated. These data can be useful for the planning of the experiments on the direct laser cooling of the monohalides of alkaline earth metals.
subject: Theoretical Physics
  topic: section
subject: transport properties
  topic: keywords
subject: collision integrals
  topic: keywords
subject: radium monohalides
  topic: keywords
subject: laser cooling
  topic: keywords
creator: Darya N. Meniailava
creator: Maksim B. Shundalau
creator: Yong-Chang Han
rights: Copyright (c) 2022 Journal of the Belarusian State University. Physics
date: 2022-02-08
publication date: 2022-02-08
starting page: 52
ending page: 64
doi: 10.33581/2520-2243-2022-1-52-64

Crystal growth and f – f transition intensities analysis of praseodymium ions in yttrium-aluminum orthoborates
type: item
description: A Pr3+ : YAl3(BO3)4 crystal with sizes of 20 × 10 × 10 mm was grown from high-temperature solution and its structural and spectroscopic properties were investigated. The distribution coefficient of praseodymium ranged from 0.6 to 0.8, that yield to the Pr3+ ion concentration of 1.1 ⋅1020 cm–3. Visible and infrared groundstate absorption (3H4) was measurement in dependence on the polarisation. The absorption spectra of the Pr3+ : YAl3(BO3)4 exhibit pronounced polarisation anisotropy. The modified Judd – Offelt theory was applied to evaluate the transitions intensities in absorption and emission, branching ratios and radiative lifetimes of the metastable levels 3P0 and 1D2.
subject: Optics and Spectroscopy
  topic: section
subject: flux growth
  topic: keywords
subject: rare-earth aluminum borates
  topic: keywords
subject: praseodymium
  topic: keywords
subject: absorption
  topic: keywords
subject: transition intensities
  topic: keywords
creator: Maxim P. Demesh
creator: Konstantin N. Gorbachenya
creator: Viktor E. Kisel
creator: Elena A. Volkova
creator: Viktor V. Maltsev
creator: Elizaveta V. Koporulina
creator: Alexey A. Kornienko
creator: Elena B. Dunina
creator: Nikolay V. Kuleshov
rights: Copyright (c) 2022 Journal of the Belarusian State University. Physics
date: 2022-02-03
publication date: 2022-02-03
starting page: 4
ending page: 13
doi: 10.33581/2520-2243-2022-1-4-13

Outlook for nuclear physics research in Belarus
type: item
description: The future nuclear physics research capabilities for scientists from Belarus are discussed. The following branches for the activity: megascience class research platforms created in Russia and the European Union, a new generation of ionizing radiation sources, use of the world nuclear science network for short-term research and, monitoring of nuclear power plants are debated. The purposes of nuclear physics research are suggested to be a balanced combining of the further penetration deep into the matter, to clarify its status and time evolution and, the routine activity associated with clarifying the details of the world, for which sufficiently well-developed models have already been created. Further, the goals of nuclear physics research are specified. They include preventing the loss of knowledge in the field of nuclear physics; conservation of the acceptable qualification and its reproducibility, maintaining the appropriate level of the engineering corps for the perception of the latest knowledge. This article is based on the author’s personal experience in participating in projects of high scientific significance. The route of considering the areas of application of nuclear physics scientists’ efforts is formed according to the principle of maximum return from the highly qualified personnel (PhDs and doctors of science). Ain importance of training undergraduates and graduate students for a scientific career is underlined. Finally, a need to maintain a high level of knowledge in the branch for the expertise upon the request of the government to secure and develop the country is pointed out.
subject: Atomic Nucleus and Elementary Particle Physics
  topic: section
subject: nuclear physics research
  topic: keywords
subject: research platform
  topic: keywords
subject: ionising radiation
  topic: keywords
subject: accelerator
  topic: keywords
subject: collider
  topic: keywords
subject: reactor
  topic: keywords
creator: Mikhail V. Korzhik
rights: Copyright (c) 2021 Journal of the Belarusian State University. Physics
date: 2021-10-11
publication date: 2021-10-11
starting page: 62
ending page: 66
doi: 10.33581/2520-2243-2021-3-62-66

Improving the efficiency of an industrial silicon solar cell by doping with nickel
type: item
description: The possibility of adjusting the operational parameters of industrial solar cells produced by the company Suniva based on monocrystalline silicon by means of additional diffusion doping with nickel in the temperature range 700–1200 °C has been investigated. It is shown that the optimal temperature of nickel diffusion is Tdiff = 800–850 °C. In this case the value of the maximum power Pmax increases by 20–28 % in relation to the parameters of the original industrial photocell. At diffusion temperatures Tdiff > 1000 °C, a sharp decrease in Pmax occurs, which is associated with an increase in the depth of the p–n-junction due to the distillation of phosphorus atoms during high-temperature diffusion of nickel. The positive effect of diffusion alloying with nickel on the electrophysical parameters of photocells is greatest in the case when the nickel impurity clusters are in the region of the p–n-junction, i. e. with diffusion alloying to the front side of the plate. The action of electrically neutral nickel clusters is less pronounced when they are located in the region of the isotypic p–p+ transition; in case of diffusion alloying with nickel in the opposite side of the plate.
subject: Semiconductor Physics and Engineering
  topic: section
subject: silicon photocell
  topic: keywords
subject: maximum power
  topic: keywords
subject: nickel diffusion
  topic: keywords
subject: nickel-enriched layer
  topic: keywords
creator: Mukhamed Kabir Bakhadirkhanov
creator: Zoir Toxir Kenzhaev
creator: Bayrambay K. Ismaylov
creator: Vladimir B. Odzhaev
creator: Uladislau S. Prasalovich
creator: Yuri N. Yankovski
rights: Copyright (c) 2021 Journal of the Belarusian State University. Physics
date: 2021-09-29
publication date: 2021-09-29
starting page: 32
ending page: 39
doi: 10.33581/2520-2243-2021-3-4-12

Formation of holographic diffraction gratings in thin films of chalcogenide glassy semiconductors
type: item
description: The paper presents a study of the formation of holographic diffraction gratings in thin films of chalcogenide glassy semiconductors. The recording process of holographic gratings at the argon-laser radiation wave length 488 nm and the process of chemical etching that enables the formation of а relief holographic grating are analysed. The optimum conditions for the formation of diffraction gratings in films of arsenic sulfide As2S3 are defined. It is shown that at the 488 nm wave length of an argon laser the optimum exposure comes to ∼5–8 J/cm2. At the recording stage a quasi-phase (relief-phase) grating is formed, with the diffraction efficiency on the order of a few per cent. Etching of the exposed sample with a solution of NaOH alkali in deionised water and isopropanol makes it possible to increase considerably the relief depth and to improve the diffraction efficiency of a thin diffraction grating approximately up to 20 % for the red spectral region, and to approach the maximal value ∼34 % for the near infra-red region. The results of the study considered look promising for the creation of relief holographic gratings which are essential in present-day optical instrument building (production of spectral devices, holographic sights, and the like).
subject: Laser Technology
  topic: section
subject: holographic grating
  topic: keywords
subject: diffraction structure
  topic: keywords
subject: chalcogenide glassy semiconductor
  topic: keywords
subject: photoresist
  topic: keywords
creator: Andrian M. Nastas
creator: Mikhail S. Iovu
creator: Igor N. Agishev
creator: Ilya V. Gavrusenok
creator: Elena A. Melnikova
creator: Ihar V. Stashkevitch
creator: Alexei L. Tolstik
rights: Copyright (c) 2021 Journal of the Belarusian State University. Physics
date: 2021-10-05
publication date: 2021-10-05
starting page: 4
ending page: 11
doi: 10.33581/2520-2243-2021-3-4-11

Incoherent ultrarelativistic channeling particle scattering by electrons
type: item
description: The problem of high-energy charged particle motion in the field of atomic strings and planes of oriented crystals, widely applied to control large accelerator beams and generate intense gamma radiation, is addressed. Following the previously developed theory of channeled particles incoherent scattering by crystal atom nuclei, we consider here the same by crystal atom electrons. The theory developed takes into consideration all the effects of momentum transfer between fast particles and electrons of atoms in a crystal in the range from the nuclear radius up to the many inter-atomic distances. The theory also includes the temperature-dependent Debye – Waller factor, as well as both the atomic form factors and scattering function, evaluated with the detail consideration of atomic structure. All the modifications of electron scattering in crystals are reduced to the value of the effective minimum momentum transfer, which by an order of value exceeds that one, related with the Bethe – Bloch mean atomic energy. Substituting this quantity to the expression for the mean square of the scattering angle of a classically moving particle makes it possible to compare the scattering by electrons and nuclei, while its joint use with the Rutherford cross section allows for the correct simulations of the planar channeling of positively charged particles in the thickest crystals, supposed to be used for the beam extraction from high energy accelerators, measurement of electromagnetic characteristics of short-living particles and development of intense narrow-band X-ray and gamma radiation sources based on crystal undulators.
subject: Atomic Nucleus and Elementary Particle Physics
  topic: section
subject: high energy
  topic: keywords
subject: relativistic quantum mechanics
  topic: keywords
subject: particle channeling in crystals
  topic: keywords
subject: bent crystals
  topic: keywords
subject: scattering by electrons
  topic: keywords
subject: coherent scattering
  topic: keywords
subject: incoherent scattering
  topic: keywords
creator: Viktor V. Tikhomirov
rights: Copyright (c) 2021 Journal of the Belarusian State University. Physics
date: 2021-09-27
publication date: 2021-09-27
starting page: 49
ending page: 61
doi: 10.33581/2520-2243-2021-3-49-61