Journal of the Belarusian State University. Physics最新文献

{"title":"Structure formation and peculiarities of crystallisation of lead-free tin – zinc alloys obtained by rapid solidification","authors":"D. Zernitsa, V. Shepelevich","doi":"10.33581/2520-2243-2022-3-48-55","DOIUrl":"https://doi.org/10.33581/2520-2243-2022-3-48-55","url":null,"abstract":"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.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82645495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measuring liquid density in a system for ensuring uniformity of measurements","authors":"N. Bakovets, Ekaterina N. Konicheva","doi":"10.33581/2520-2243-2022-3-113-119","DOIUrl":"https://doi.org/10.33581/2520-2243-2022-3-113-119","url":null,"abstract":"The article presents the results of a study aimed at creating the national standard for liquid density. The standard provides reproduction, storage and transmission of the liquid density unit in the range from 650 to 2000 kg/m3. Based on the method of hydrostatic weighing, the measurement of liquid density was implemented in accordance with the GOST OIML R 111-1-2009 «State system for ensuring the uniformity of measurements. Weights of classes Е1, Е2, F1, F2, M1, M1–2, M2, M2–3 and M3. Part 1. Metrological and technical requirements». It is shown that the use of a high-precision mass comparator can significantly reduce the systematic measurement error and the standard deviation when reproducing and transferring the unit of liquid density to reference measuring instruments of the 1st and 2nd category and working measuring instruments. A method for transferring a unit of liquid density by means of a standard density measure – a silicon sphere and a comparator liquid – has been implemented, which made it possible to exclude the transfer link in the form of a standard liquid density solution. In the range of reproduction, storage and transmission of the liquid density unit, a systematic error of 2.1 ⋅ 10–3 kg/m3 was obtained, the standard deviation in the reproduction of the liquid density unit was 4.0 ⋅ 10–4 kg/m3, the standard deviation of the total error in the transmission of the liquid density unit 3.14 ⋅ 10–3 kg/m3.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77100831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Equivalent circuits of FeCoZr-alloy nanoparticles deposited into Al2O3 and PZT dielectric matrices nanogranular composite films","authors":"A. Larkin, A. Fedotov","doi":"10.33581/2520-2243-2022-3-104-112","DOIUrl":"https://doi.org/10.33581/2520-2243-2022-3-104-112","url":null,"abstract":"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.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75620494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"«Uncanny valley» effect in holographic image transmission","authors":"S. Shoydin, A. Pazoev","doi":"10.33581/2520-2243-2022-3-4-9","DOIUrl":"https://doi.org/10.33581/2520-2243-2022-3-4-9","url":null,"abstract":"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.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84146048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of the reciprocal lattice of crystals with non-primitive Bravais cells","authors":"V. Liopo, I. Liaushuk","doi":"10.33581/2520-2243-2022-3-68-80","DOIUrl":"https://doi.org/10.33581/2520-2243-2022-3-68-80","url":null,"abstract":"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.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77420357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal and thermoelectric properties of ceramics based on zinc oxide alloyed with iron","authors":"Aliaksei V. Pashkevich, Ludmila A. Bliznyuk, A. Fedotov, V. Khovaylo, A. Kharchanka, V. Fedotova","doi":"10.33581/2520-2243-2022-3-56-67","DOIUrl":"https://doi.org/10.33581/2520-2243-2022-3-56-67","url":null,"abstract":"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 electricalresistivity 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.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87643822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Increasing the metrological characteristics of anechoic chambers due to a posteriori analysis based on artificial neural networks","authors":"Yuliya S. Harshkova, Sergey V. Maly, A. Tkachenia, I. Kheidorov","doi":"10.33581/2520-2243-2022-3-93-103","DOIUrl":"https://doi.org/10.33581/2520-2243-2022-3-93-103","url":null,"abstract":"This article considers the possibility of improving the metrological characteristics of an anechoic chamber due to a posteriori processing of measurement results based on a generative adversarial model of an artificial neural network in order to reduce the influence on the distribution of the electromagnetic field in the measuring zone of waves reflected from the outer boundaries of the chamber and the equipment located in it. The training of the neural network was carried out on a data set obtained as part of a computational experiment and including the distribution of the electromagnetic field in the anechoic region for the model of an anechoic chamber and free space for given source layouts. The distributions of the real and imaginary parts of the electric component of the electromagnetic field were encoded with colour images. On the example of two-dimensional models of anechoic chambers, the practical feasibility of the proposed approach to a posteriori processing of measurement results is shown. Methods for estimating the accuracy of a posteriori processing of measurement results based on the metrics used to assess the quality of graphic images and calculating the errors in the amplitudes of the electric component of the electromagnetic field are given. The possibility of implementing the proposed method of a posteriori analysis in the framework of natural microwave measurements in anechoic chambers is assessed.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90835534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electrophysical characteristics of power MOSFETs additionally implanted with nitrogen ions","authors":"V. Odzaev, A. Pyatlitski, U. Prasalovich, N. Kovalchuk, Yaroslav A. Soloviev, D. V. Shestovski, V. Yavid, Yu.N. Yankovski","doi":"10.33581/2520-2243-2022-3-81-92","DOIUrl":"https://doi.org/10.33581/2520-2243-2022-3-81-92","url":null,"abstract":"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 explained by a decrease in the density of surface states at the Si – SiO2 interface in MOS-structures created using an additional operation of nitrogen ion implantation in the direct order of heat treatment.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81390768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Classification of Norway spruce drying states on the basis of reflection spectra","authors":"A. Martinov","doi":"10.33581/2520-2243-2022-3-26-38","DOIUrl":"https://doi.org/10.33581/2520-2243-2022-3-26-38","url":null,"abstract":"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 %.","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81568275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of high-temperature ion irradiation on nanostructured TiAlN coatings","authors":"S. Konstantinov, F. Komarov, Igor V. Chizhov, J. Żuk, V. A. Zaikov","doi":"10.33581/2520-2243-2022-3-39-47","DOIUrl":"https://doi.org/10.33581/2520-2243-2022-3-39-47","url":null,"abstract":"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. ","PeriodicalId":17264,"journal":{"name":"Journal of the Belarusian State University. Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83829707","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}