Search

Copyright of Electronic Processing of Materials / Elektronnaya Obrabotka Materialov is the property of Institute of Applied Physics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Inhomogeneities in the near-surface region of diffusion-doped silicon with manganese atoms were studied using the local photo-EMF method and photovoltage and photoconductivity signals were detected. It has been established that the inhomogeneous region is located at a depth of 3÷35 μm from the surface of the crystal. The magnitude of photo-EMF in these layers does not change monotonically from point to point. It was revealed that the photo-EMF spectra depend on the wavelength of the irradiated light, while the shape of the areas and their shift are related to the penetration depth of laser radiation. The photo-EMF signal increases to a depth of ~25 µm from the surface, then saturates and from ~30 µm smoothly decreases and completely disappears at a depth of ~40 µm. The magnitude of the internal electric field was determined using the Tauc method. A model of the structure of the near-surface region of diffusion-doped silicon with manganese is proposed.

In this work the mechanism of current flow during illumination with hν≥Eg in the temperature range of 77÷300 K is considered. It is established that in the PtSi – Si-M structure in the temperature range of 77÷270 K the regime of space charge limited currents (SCLC) is realized. The current-voltage characteristics of the structures show areas of linear and quadratic dependences of current on voltage, as well as areas of a sharp increase in current. These features of the current-voltage characteristic are explained by the presence of deep level structures and sticking levels for charge carriers in the base region. From the temperature dependence of the SCLC, the concentration of adhesion levels was determined to be equal to (1.8÷3) 1015 cm-3 and the adhesion factor to be equal to 6.32·10-2. In the temperature range 77÷115 K at voltages 0.2÷1 V, the current-voltage characteristic obeys the law J ~ Un(n=3÷4), and above U – the law J ~ U6, followed by a transition to the quadratic law.

In this research, a comprehensive study of the effect of doping silicon with gold on the optical properties and morphology of silicon layers was carried out. For this purpose, the methods of Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) were used. The results of the study showed that the transition from original silicon to gold-doped silicon leads to significant changes in the optical properties and morphology of the layers. Raman spectra showed characteristic peaks in the regions of 144, 304, 402, 464, 522, 948 and 973 cm–1, associated with the violation of long-range order of the crystal lattice and the interaction of gold with silicon. The intensity and position of the peaks in the spectra allowed us to draw conclusions about structural changes, including a decrease in crystallinity and the formation of amorphous and nanocrystalline structures in the samples after treatment at 1373 K. New peaks in the Raman spectra associated with Au-Au stretching and the formation of new bonds Si-Au, confirm the processes in silicon layers when alloyed with gold. SEM studies provided information on the structure, chemical composition and arrangement of n-Si-Au and p-Si-Au samples. The spherical arrangement of gold atoms on the surface of single-crystalline silicon was experimentally established, which indicates the diffusion of gold and the formation of gold silicate, which introduces a positive charge to the interface. Morphological changes included an increase in the number of agglomerates with nanocrystals smaller than 7–9 nm and an increase in the transparency of the layer. These results indicate the possibility of improving the photosensitivity of heterostructures with a Si–Au composite layer due to the quantum-size and plasmonic effects of inclusions containing silicon and gold nanoparticles.

The paper describes the research and study of the process of electrically induced diffusion of Mn atoms in silicon directly from a Si surface layer that was preliminarily enriched with Mn. To ensure the so-called electrically induced diffusion process, a constant electric field was applied to the investigated samples. It has been revealed that as a result of the diffusion of Mn impurity atoms into samples placed at the negative pole of the electrical diffusion unit, the proportion of Mn atoms was 75.4% (relative to silicon atoms), while in samples placed at the positive pole this indicator tended to be 2.7% (relative to silicon atoms). Besides that, for the first time, an experimental increase in the electro-active concentration of Mn impurity atoms in silicon (at T = 900°C) was detected under the influence of an external constant-value electric field. In this case, the maximum solubility of impurity atoms of Mn at a temperature of T = 900°C was NMn~2.27·1014 cm-3, while the average concentration of electro-active Mn atoms diffused into silicon under the influence of an external constant electric field reached NMn*~2.62·1014 cm-3.

In this work, the structural and optical characteristics of silicon (n-Si) samples and its compositions with dysprosium (n-Si-Dy) were analyzed using Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy methods. Characteristic peaks in the FTIR spectra such as 640 cm-1 (Si-H mode) and 1615 cm-1 (perpendicular stretching mode) were identified, indicating the structural features of the material. The appearance of additional peaks in the n-Si-Dy spectra at 516.71 cm-1 and 805 cm-1 indicates the influence of dysprosium on the structure and defectiveness of the material. Examination of the frequency range (1950–2250 cm-1) further confirms local vibration modes associated with defects and interactions with dysprosium. Peaks associated with Dy-Dy stretching, as well as interaction with silicon, were found at 2110 cm-1 and 2124 cm-1. Analysis of Raman spectra indicates the formation of silicon nanocrystals during annealing, which is confirmed by XRD results. The results obtained provide important insight into the effect of dysprosium on the structure and properties of silicon materials, which could potentially find application in optoelectronics and materials science.

The study of thin-film nanocomposites, including crystalline and amorphous silicon nanoparticles embedded in silicon oxide layers, is a key direction in the field of materials for optoelectronics. This study explored the interest in such composites, including erbium silicide (ErSi2-x), in the context of their applications in non-volatile memory and photovoltaic devices. Particular attention was paid to the structure and properties of such materials, including the analysis of defects in erbium-doped silicon. The results of the study, based on Raman spectroscopy and X-ray phase analysis, made it possible to identify the characteristics of the composition and structure of the studied samples. The identified data confirmed the presence of crystalline phases of Si and Er in the p-Si-Er composite, and also showed the substitution of Er in the p-Si/SiO2 structure. Additionally, X-ray microanalysis data confirmed the presence of Si, O and Er in the expected concentrations in the composite film. Further research showed that the introduction of erbium atoms onto the silicon surface leads to minor changes in some signals and the appearance of new vibrations in the Raman spectra of the samples. The decrease in the intensity of the peaks belonging to silicon is associated with the weakening and breaking of some bonds in the structure of the silicon crystal lattice and due to the formation of new bonds in which erbium atoms participate. Thus, the results of this study represent a significant contribution to the understanding of the properties and potential of thin film nanocomposites for applications in optoelectronics, and also enrich our knowledge of the effect of doping on the structure and properties of silicon materials.

In this paper, using a scanning electron microscope (SEM) and atomic analysis, the location map of microcomposites formed on the surface of n-Si, p-Si, n-Si and p-Si samples was studied. Force microscope (AFM) research devices. The atomic fractions of inclusions of carbon, oxygen and lutetium formed on the surface of the samples were studied. Also, using the ASM device, the sizes, relief and topographic appearance of defects formed on the surface of the samples were determined. In silicon samples doped with Lu, a decrease in the size of surface defects and the formation of nano-sized structures were found, which makes it possible to obtain materials with a more perfect crystal structure. Using a ZEISS GeminiSEM 300 scanning electron microscope, the structural structure, chemical composition and images of their arrangement of n-Si, p-Si, n-Si and p-Si samples were obtained. In this case, the electron accelerating voltage was 20 kV, and the pressure in the sample chamber was (10-3 mmHg). Research results show that the structural structure of micro- and nanocomposites formed in silicon mainly depends on the diffusion time and cooling rate of the samples after diffusion annealing.

Each crystal structure has its own phonon modes, which appear in the Raman spectrum of Raman scattering. In the case of silicon, phonon modes associated with the diamond structure of silicon can be detected. In a Raman spectrum, the position of the lines, their intensity, and the width of the lines are usually measured. Raman spectroscopy is a powerful tool for studying crystalline materials at the molecular level, and its application in the study of semiconductors and nanomaterials provides important information about their structure and properties. In this study, the spectra of two types of silicon were analyzed: n-Si and p-Si, as well as their doped analogues n-Si and p-Si. The obtained Raman imaging results demonstrated spatially varying nanocrystallinity and microcrystallinity of the samples. The n-Si and p-Si spectra indicate the appearance of a Raman band at 525 cm-1 with a shift of -5 cm-1 and +5 cm-1, respectively, relative to the position of the silicon substrate peak, indicating the presence of tensile strain in the materials. The absence of other impurity peaks indicates the high purity of the n-Si and p-Si samples. The holmium doped Si material exhibits additional peaks in the Raman spectra, which is attributed to the presence of vacancies and defects in the newly formed Si-Ho compositions. The results of the analysis of the spectra indicate the influence of doping silicon with holmium on its structure and properties, forming new bonds and defects.

Transient global amnesia (TGA) is a benign, stress-induced neurological syndrome associated with reversible hippocampal dysfunction that manifests as isolated, predominantly anterograde amnesia. Since it is impossible to make a definitive diagnosis of TGA when the patient is admitted to hospital, the primary condition should be interpreted as an acute cerebrovascular accident, which implies a mandatory neuroimaging examination and clarification of the question of thrombolysis according to general principles. When taking a medical history, attention should be paid to the presence of predisposing conditions and triggers: migraine, chronic and acute stress, physical activity, sudden changes in temperature, Valsalva maneuver, coitus, medical procedures. If amnesia does not resolve within 24 hours, a differential diagnosis with stroke, Wernicke–Korsakoff encephalopathy, limbic encephalitis, intoxication and psychogenic (dissociative) amnesia is required. If the symptoms resolve within 24 hours and the classic diagnostic criteria are met, magnetic resonance imaging of the brain in diffusion-weighted mode is performed on days 2 to 4 in order to detect pinpoint zones of diffusion restriction in the hippocampus. If these lesions are visible and a typical medical history is available, the diagnosis of TGA can be made; if no lesions are present, the diagnosis is probable. In the absence of lesions and an atypical history of TGA, differentiation from transient epileptic or dissociative amnesia and transient ischemic attack is required.

Copyright of Electronic Processing of Materials / Elektronnaya Obrabotka Materialov is the property of Institute of Applied Physics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Electronic Processing of Materials / Elektronnaya Obrabotka Materialov is the property of Institute of Applied Physics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Electronic Processing of Materials / Elektronnaya Obrabotka Materialov is the property of Institute of Applied Physics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of German International Journal of Modern Science / Deutsche Internationale Zeitschrift für Zeitgenössische Wissenschaft is the property of Artmedia24 and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The purpose of the study is to identify the features and problems of diffusion of the client base of IT enterprises in Ukraine, to develop recommendations for solution of the latter. The article outlines the general situation in the IT market, in particular, draws attention to its turbulence and high instability of consumer preferences, when supply in the market dominates over demand. The components of the concept of «diffusion of client bases of enterprises» are considered. Under the concept of «diffusion» it is proposed to consider the conception that describes the patterns of distribution of cultural, social, economic and other phenomena, initially concentrated in one or more places, which imply the presence of a certain share of uncertainties, and «client base» – as the main source of business and income of the enterprise, containing information about both existing and potential clients. The main advantages of maintaining a client base of activities are presented, in particular: preservation of data; transfer of a client from one manager to another; analysis of the market situation; assessment of the target audience; formation of marketing strategy and business development. It is noted that client-oriented business management allows to increase the profit and overall efficiency of the enterprise by increasing the amount of revenue from the existing client base, as well as by optimizing operating costs. The stages of formation of the client base of activity for IT enterprises are proposed and detailed as: planning, development, implementation, and analysis. Attention is drawn to the matter that the main indicator of the diffusion of the client base of an IT enterprise is the «drawdown» of sales, which can be caused by both internal and external factors of influence. The statistics of changes in the geography of hiring on the example of the largest domestic IT enterprises, which is one of the indicators of client behavior, has been studied. It is noted that large enterprises do not experience the diffusion of the client base of activity to the same extent as it happens with small companies, so the diffusion of the client base of IT enterprises from Ukraine is not a mass phenomenon. Recommendations to encourage clients to cooperate with Ukrainian IT companies are proposed. Prospects for further research in this direction are the study of the specifics of the recovery of global demand in the IT industry after the recession.

The literary data dealing with the experimental studies concerning the influence of electromagnetic phenomena on the diffusion processes are reviewed and analysed. Based on the scientific facts presented in interdisciplinary experimental studies, a hypothesis is suggested. It is concerned with the influence of electromagnetic phenomena in the process of formation of a diffusion joint during pressure welding through a layer of a hydrocarbon substance. In the welded joint, at the initial moment of current transmission, energy is released during the explosion at the points of contact. When a pulsed electric current is passed through the pyrolysis products in microvolumes between the surfaces to be joined, they are also destroyed. Ionized particles are formed. Under the action of the pinch effect, they move to the centre of the welded joint. A capsule with ionized carbon particles is formed there. The ‘Coulomb explosion’ occurs in the capsule located in the middle of the joint. Multiple exposures of the surfaces by microexplosions in microvolumes between the surfaces to be joined and the final ‘Coulomb explosion’ of the capsule create the release of a large number of magnetic monopoles. This can be a determining and synergistic factor among a number of others in the formation of a welded joint. This makes it possible to explain the short time required for welding and the small deformations of the weld formation zone.

This paper presents the results of a study of the state of ytterbium atoms in silicon, carried out using the methods of Fourier transform infrared spectroscopy (IR) and Raman spectroscopy (RS). Silicon samples doped with ytterbium impurities were analyzed using FSM-2201 and SENTERRA II Bruker spectrometers. Registration and identification of both crystalline and amorphous phase components in the samples was carried out. The results of the study confirm that doping silicon with ytterbium impurities leads to a decrease in the concentration of optically active oxygen by 30-40%, depending on the concentration of the introduced impurities. It was also found that an increase in the number of defects leads to a broadening of the amorphous zone. It is assumed that similar dependencies exist for the Si-Yb system; however, to the best of our knowledge, similar results have not been reported previously. It is noted that the relative intensity of the three Raman bands in Si-Yb systems in the LTIOS (The light and temperature induced ordered state) state changes, and the relative intensity of Si-Si decreases. This indicates that pendant bonds are mainly formed by the breaking of Si-Si bonds. It was also observed that the light intensity causing this condition is far from that required for laser or solid phase crystallization. Using the Raman spectroscopy method, a structural transformation was discovered, expressed in a densely packed array of nanocrystals with a size of less than 11 lattice parameters. Small clusters were under strong internal stress (up to 3 GPa), which probably prevents the cluster size from increasing beyond the critical value for irreversible crystallization.

The paper reports the sharp increase in resistivity and the conductivity change (type) in the single-crystal silicon sample doped with vanadium. The electrical and optical properties of single-crystalline silicon were determined Hall- and four-probe measurements and infrared (IR-) spectroscopy. Relative resistance, charge carrier concentration, mobility, and concentration of optically active oxygen and carbon in the samples were determined layer-by-layer. It is shown that in silicon samples doped with vanadium the concentration of optically active oxygen atoms tends to reduce.

It is shown that the dynamics of changes in the state of nickel clusters depends on the temperature of the diffusion maximum and the cooling rate. It was found that with increasing annealing temperature and cooling rate, an increase in density and a decrease in cluster size are observed. In this case, the main attention was paid to the determination of the laws governing the change in the density, size, and structure of clusters from temperature and cooling. The process and dynamics of the interaction of clusters depends on the diffusion coefficient of impurity atoms in the lattice and the level of supersaturation of the solid solution. It has been established that with a change in the annealing temperature from T = 1100℃ to 1250℃, the cluster density increases by almost 1-1.5 orders of magnitude, and their size decreases by a factor of 5–6. It seems to us that to obtain clusters with stable parameters, the optimal cooling rate is 200–300℃.

Background: Metastatic brain lesions lead to the most unfavorable prognosis for the course of an oncological disease. Most often, brain metastases arise from primary tumors such as lung cancer, breast cancer, and melanoma. Of particular interest are groups of secondary intracranial tumors without an identified primary focus. Methods of non-invasive differential diagnosis based on a possible histological affiliation, including diffusion-kurtosis magnetic resonance imaging, can improve the diagnostic search for the primary tumor. Aim: The aim of this study is to improve the quality of differential diagnosis for brain metastases of tumors of different primary localization by introducing the diffusion-kurtosis magnetic resonance imaging technique into the magnetic resonance scanning protocol. Methods: Our work included studies of 60 patients who underwent examination and treatment at the N.N. Blokhin National Research Medical Center of Oncology of the Ministry of Health of Russia from October 2019 to March 2022. According to magnetic resonance imaging, metastatic formations were detected in the brain of the patients, with different localizations of the primary tumor. 20 patients were diagnosed with lung cancer (33.3%), 20 patients with breast cancer (33.3%) and 20 patients with melanomas (33.3%). We evaluated the tumor size, diffusion and kurtosis parameters, such as the mean kurtosis, axial kurtosis, radial kurtosis, kurtosis anisotropy, radial diffusion, and fractional anisotropy, and relative anisotropy, axial diffusion of the extra-axonal fluid, radial diffusion of the extra-axonal fluid, axonal fluid fraction, and tortuosity of the diffusion trajectory. Results: Statistically significantly (p 0.05) differing parameters of diffusion and kurtosis in the comparative evaluation of the above indicators were identified in the structure associated with melanoma and lung cancer axial diffusion, fractional anisotropy, relative anisotropy, radial kurtosis and tortuosity of the diffusion trajectory, as well as in the structure of melanoma and breast cancer — axial diffusion, axonal fluid fraction, fractional anisotropy, axial diffusion of extra-axonal fluid, mean kurtosis, relative anisotropy, radial kurtosis and tortuosity of the diffusion trajectory. Conclusion: Diffusion-kurtosis magnetic resonance imaging is a promising technique that allows obtaining additional differential information in the case of metastatic lesions of the brain matter, especially those from an undetected primary focus.

Copyright of Electronic Processing of Materials / Elektronnaya Obrabotka Materialov is the property of Institute of Applied Physics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Electronic Processing of Materials / Elektronnaya Obrabotka Materialov is the property of Institute of Applied Physics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Electronic Processing of Materials / Elektronnaya Obrabotka Materialov is the property of Institute of Applied Physics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In nanocrystalline metals, there are grain boundaries that, under the influence of shear stresses applied along them, move along the normal. Such boundaries combine two types of the grain boundary deformation – mutual grain slippage along the boundary and its migration. This relationship is easily explained in the model of intercrystalline boundaries with mating crystallographic planes. By solving the differential equation under the action of alternating voltage, the functional dependence of the boundary displacement on the coordinate and time is found. Based on this, the value of the energy dissipated during the oscillation period and the expression for the internal friction caused by the contribution of such boundaries are found. It has the character of a Debye peak. The activation energy of the process is equal to the activation energy of the grain boundary self-diffusion. An atomic mechanism of the boundary motion is proposed, which is based on diffusion processes between extended steps of atomic scale in the boundary.

The process of diffusion of labeled copper atoms in p-CdTe coarse-block films with a columnar grain structure has been studied. The CdTe film is a p-type semiconductor, where an increase in the Pb concentration in the composition of the CdTe films increases the resistivity ρ of the structure. When the Pb concentration in CdTe changes from 1018 to 5·1019 cm-3, the hole concentration decreases by more than 3 orders of magnitude at a constant operating level depth of EV + (0.4 ± 0.02) eV. This may indicate that the concentration of acceptor defects, which are formed in the films due to self-compensation upon doping with a PbCd donor, exceeds the number of the latter. Electrical measurements by the Hall method were carried out at a direct current and a temperature of 300 K. As a result, an increase in the temperature of films on a Mo-p-CdTe substrate during annealing affects the electrical parameter of charge carrier mobility µ, it decreases significantly. X-ray diffraction analysis showed that on the diffraction patterns of samples of p-CdTe films, all available reflections correspond to the CdTe phase and up to х = 0.08 do not contain reflections of impurity phases and have a cubic modification. Based on the results of the calculation, it was established that the low values of the diffusion coefficient of Cu atoms are due to the formation of associates of the A type , which are directly dependent on the concentration of atoms. Diffusion length Ln and lifetime τn of minority current carriers in large-block p-type cadmium telluride films, which can also be controlled by introducing lead atoms into cadmium telluride.

The paper studies the properties of surface and near-surface region of a single crystalline silicon sample doped with atoms of Ga (AIII) and Sb (BV). n-type single-crystal Si wafers were chosen as substrates, and samples were size of 8×10×0.5 mm3. For diffusion into silicon, Ga and Sb impurities were used with a purity of 99.999 and 99.998, respectively. The authors propose that a new heterostructure might form in the near-surface region of silicon that could be engineered by applying a relatively cheap diffusion method. The experimental and analysis results show that the composition and absorption spectrum of silicon start manifest certain changes, and can be used in the future as a functional material for solar cells. The result showed that randomly located islands with an average diameter of 1–15 µm are formed on the substrate surface. X-ray diffraction analysis was carried out using a Rigaku diffractometer to study the crystallographic parameters of islands formed with the participation of Ga and Sb atoms on the silicon surface. The energy spectrum was studied on Nanofinder High End Raman spectrometer (LOTIS TII) in order to determine the presence of complexes of Ga and Sb atoms within islands formed as a result of diffusion. The optical emission spectra in the new structure were studied using a Lambda 950 spectrophotometer. The measurements were carried out at room temperature, i.e., at 300°K. Having studied the results of X-ray analysis, Raman spectroscopy, and optical spectroscopy, the authors have revealed that Ga and Sb atoms form new Si0.44(GaSb)0.56 and Si0.75(GaSb)0.25-type binary compounds on Si surface.

The paper determines the technological regimes for obtaining GexSi1-x alloys by introducing germanium atoms into single-crystal silicon by the diffusion method. From the results of the study, it was found that the fundamental parameters of the formed GexSi1-x alloys differ from the fundamental parameters of the original silicon, in particular, the energy values of the silicon band gap change. Elemental analysis of the surface of the samples showed that the concentration of silicon (in atomic percent) was ~70.66%, germanium ~29.36%. It was assumed that on the silicon surface and in the front part, a thin layer of an alloy of a compound with a composition of approximately Ge0.3Si0.7 (0.5÷2 μm) would be formed. Analysis of the spectra (p shows that the spectrum contains peaks ~303 cm-1 and ~406 cm-1, corresponding to the Ge-Ge and Si-Ge bonds, respectively. It was also shown that GexSi1-x binary compounds are a new material for modern electronics, the possibility of creating properties on their basis in electronics was shown. It is proposed on their basis to create devices with new functionality and highly efficient solar cells.

The paper is concerned with the study of silicon samples doped with gallium (Ga) and antimony (Sb) atoms. In particular, the elemental analysis, SEM imaging, and Raman spectrometry analysis of the samples are presented. The elemental analysis revealed that the relative concentrations of Ga (0.4) were almost equal to those of Sb (0.39) and both were formed on the surface of Si. The SEM imaging showed that GaSb microsized islands (diameter of 1 to 15 microns) and a density of ~106 cm-2 were being formed on the surface of Si in the course of the process of diffusion doping. Raman spectral analysis showed that a semiconductor with GaSb molecules self-assemble on Si surface.

In this paper, the transport characteristics of two-dimensional systems has been investigated. Modeling by means of the Yukawa potential, in a wide range of values of the nonideality parameter, has been carried out. The Yukawa potential was chosen because of its wide applicability in the description of screened interactions in plasmas and other systems. A molecular dynamics method was used to determine the transport characteristics. The study was carried out with the aim of expanding the knowledge of heat transfer in two-dimensional systems. The paper presented the results of numerical experiments in which the dependences of the heat transfer and viscosity coefficients on the screening and non-ideality parameters in systems with Yukawa potential were studied. The obtained data can also serve as a basis for further theoretical and experimental studies in the field of transport characteristics of two-dimensional systems. These data not only expand the understanding of the peculiarities of two-dimensional systems, but also can be useful in the design and analysis of nanostructures and various microdevices. [ABSTRACT FROM AUTHOR]

The article analyses technologies for the formation of coatings to protect machine and equipment parts from corrosion and wear in aggressive environments. The study considers plasma electrolytic oxidation (PEO) regimes of valve metal materials on the core, microstructure, and physical and mechanical properties of oxide coatings. To solve this problem, it is promising to develop a combined technology: application of a layer of aluminium on the surface of steel parts followed by its PEO. The purpose of this work is a theoretical study of the temperature distribution in a steel cylinder covered with a layer of aluminium during PEO to substantiate the thickness of the layers of the two-layer aluminium–aluminium oxide coating. An installation for PEO and a technological process of forming a two-layer Al–Al2O3 coating on long-dimensional parts are developed. A mathematical model is created for an infinite three-layer cylinder with an internal coaxial surface cylindrical source of heat that moves at a constant speed in the radial direction deep into the aluminium layer of the cylinder. It is based on solving the boundary value problem of thermal conductivity with the condition of ideal thermal contact between the layers. During PEO, a solid oxide layer is formed, but the thickness of the unoxidized aluminium layer decreases. The thermophysical characteristics of such a cylinder are functions of both the radial co-ordinate of the cylinder and the time. During the construction of a two-layer coating, it is advisable to use the results of thermal calculations to justify the thickness of the unoxidized aluminium layer adjacent to the surface of the steel under the condition of ensuring the flow of mutual diffusion processes at the interface between aluminium and steel to increase the adhesion strength of the coating to the base due to heating by instantaneous heat sources caused by the action of electric-spark discharges in the PEO process. The thickness of the outer solid layer of aluminium oxide is chosen based on the condition of ensuring the necessary service life of machine parts for wear with a certain reservation. The results of mechanical, tribological, and corrosive cracking tests for steel samples with the developed two-layer Al2O3 coating show its high operational properties.

This article presents experimental results on the technology of obtaining and studying the lateral photoelectric effect (LPE) in hybrid structures (HS) of the Fe/SiO2/p-Si and Fe/SiO2/n-Si types. The technology for obtaining such HS consists of two parts: firstly, obtaining compensated (C), highly compensated (HC), and over-compensated (OC) samples of Si . Secondly, obtaining HS Fe/SiO2/p-Si and Fe/SiO2/n-Si. Based on the results, it is shown that sufficiently good HS has been obtained. Experiments on the study of LPE have shown that in the studied HS there is a pronounced manifestation of the lateral photoelectric effect, the magnitude and nature of which strongly depend on the type of conductivity and resistivity of the compensated silicon. The observed features are explained by the fact that in С, HC, and OC silicon samples, impurities that create deep levels in the silicon band gap form various multi-charged complexes that modulate the energy band of silicon, which lead to significant changes in its physicochemical and generation-recombination properties, which underlies the observed effects. Based on the LPE studies, depending on the contact distance, it is possible to determine the numerical values of the diffusion lengths of the minor current carriers (Lp and Ln), their lifetimes (τp and τn), and diffusion coefficients (Dp and Dn) on the substrate material.

The work analyzes the dependence of the diffusion index of high-energy negatively charged particles on the energy of the transverse motion in oriented crystal. The crystal had an axial orientation relative to the direction of particle incidence. The analysis was carried out using the example of π− mesons with a momentum of 100 GeV/c that impinged on a silicon crystal, which corresponds to the conditions achievable on secondary beam of the the CERN SPS accelerator. The analysis showed that the dependence under consideration is not monotonic. It has a minimum in the energy region slightly exceeding the value of the potential energy of particles at the saddle point of the potential of crystal atomic strings. At higher values of the energy of transverse motion of particles E⊥, the diffusion index increases with increasing E⊥, since this increases the average absolute value of the velocity of particle motion in the plane orthogonal to the crystal axis, near which motion takes plase. The increase in the diffusion index at low values of E⊥ is associated with the manifestation of incoherent scattering of particles on thermal vibrations of crystal atoms. The analysis carried out in the work is of interest both for a deeper understanding of the process of high-energy negatively charged particle beams passage through oriented crystals, and for improving methods for charged particle beams steering with a help of straight and bent oriented crystals.

The temperature dependence of the mobility in chromium silicides in the temperature range of 80 ÷ 780 K was studied. The mobility gradually increases to a temperature of 350 K, then it saturates in the temperature range of 350 ÷ 450K, then gradually decreases. It is shown that the mobility depends on the scatter of charge of carriers on a crystal lattice, impurity ions, dislocations, and silicide inclusions. The frequency of collisions is proportional to T3/2, and the mobility varies with temperature as T-3/2. At high temperatures, phonons may be considered as “frozen” defects and collision frequency with its will proportional to T. The temperature dependences of the electrical conductivity in this temperature range were also studied. Areas with negative and positive temperature coefficients are revealed.

In this work, lutetium-doped silicon samples were studied using the Raman scattering method. Registration and identification of both crystalline and amorphous phase components in the samples was carried out. There is some violation in the spectra of Raman scattering of light samples of silicon doped with lutetium in comparison with the original sample. It was found that the intensity of Raman scattering of doped samples is 2-3 times higher than the scattering from silicon. The comparison is carried out for the intensities associated with the intensities of the single-phonon line of the silicon substrate. This effect of the Raman spectra in the range 930 cm‑1 – 1030 cm–1 appearing in this range is similar to the data reduction for multiphonon propagation on silicon. For the obtained images (n-Si and p-Si), the bands in the atomic range of combinatorial scattering have a mixed broad and oval background in the range from 623 cm-1 to 1400 cm-1. This background can change the shape of the observed bands.

This research paper presents the findings of an investigation into the interaction between zinc (Zn) and nickel (Ni) impurity atoms within a silicon (Si) matrix, which were doped sequentially in various combinations. The characterization techniques employed for this study encompass X-ray diffraction and IR-Fourier spectrometry. It is noteworthy that the degree of crystallinity exhibited by the silicon lattice, subject to the introduction of Zn and Ni impurities, is contingent upon the methodology employed for impurity incorporation. The results of this study reveal a distinctive trend in the optical properties of these doped silicon samples. Specifically, upon the introduction of Zn atoms into silicon that was pre-doped with Ni (Si), there is a concomitant reduction in the concentration of optically active oxygen atoms. Remarkably, this alteration in the dopant composition leads to a marked enhancement in the transparency of the silicon crystal. In stark contrast, when the doping sequence is reversed (Si Ni>), an opposing effect is observed, resulting in a diminishment of crystal transparency. These findings underscore the intricate interplay between the introduced impurity atoms, the dopant sequence, and their collective impact on the optical properties of the silicon matrix. Such insights contribute to our comprehension of the nuanced behavior of doped silicon and have implications for applications requiring tailored optical characteristics in semiconductor materials.

The paper presents the results of an experimental study of surface morphology, elemental composition, electrophysical and optical properties of Si samples earlier doped with impurity atoms of Zn and S. The results of the study revealed a sufficient concentration of Zn and S elements on Si surface after diffusion (3.1% and 2.6% by weight, respectively). After additional thermal treatment at different temperatures, i.e., at 850°C and 875°C, the samples of I group have regained their initial parameters. However, it’s noteworthy that the mobility of charge carriers in group I samples was comparatively lower than that in group II samples allegedly under the influence of Zn and S binary molecules. After additional heat treatment of all samples at a temperature of 875°C, the authors have studied optical absorption coefficients. And their band gap energies were determined using the Tauc Plot method. According to the results of the study, the optical band gaps in group II and III samples were 1.12 eV, whereas the band gap energy in group I samples after additional thermal treatment at a temperature of 875 °C turned out to be 1.31 eV. Having theoretically calculated the band gap by applying Vegard’s law, the authors suggested that the new structure must be of Si0.92ZnS0.08 - type.

One of the crucial phenomena is auto-oscillations of current in elementary and binary (AIIIBV, AIIBVI) semiconductor materials, which allow the creation of solid-state oscillators with a wide frequency range from 10-3 to 10-6 Hz. In this paper, we show the results of a study on the effect of the degree of compensation (K) and the concentration of electroactive impurity selenium atoms on the excitation conditions and parameters (amplitude, frequency) of the auto-oscillation current associated with temperature and electrical instability in silicon. In the research, silicon doped with selenium atoms Si of identical geometrical dimensions has been used. The compensation degree of the initial boron atoms with impurity selenium atoms in the samples is in the range of K = 2NB/NSe = 0.94-1.1. It was found that excitation conditions, the amplitude and frequency of auto-oscillation current significantly vary depending on the degree of compensation of selenium atoms with boron atoms in the initial silicon. Obtained experimental results showed that the auto-oscillation current in silicon doped with impurity selenium atoms is characterized by ease of control with stable parameters (amplitude and frequency), which makes it possible based on this unique physical phenomenon to develop and create oscillatory circuits in information technology.

This article discusses the electrical properties of silicon doped with rare earth elements (REE). Atoms of rare earth elements (REE) diffused onto the surface of the silicon substrate. To measure the electrical parameters, samples of n-Si, n-Si, n-Si and n-Si were prepared and their electrical properties were determined using the Hall effect, four-probe and thermal probe methods. The studies were carried out in the temperature range 77÷300 K. The samples were ohmically contacted using a mixture of 1% Sb + 99% Au for measurement on the HMS500 instrument. The specific resistance of the samples in layers, the concentration of charge carriers, and the mobility of the samples were also studied by the magnetoresistance method. The electrical parameters of the samples were measured on an Ecopia Hall effect measuring system (HMS5000).

Copyright of Electronic Processing of Materials / Elektronnaya Obrabotka Materialov is the property of Institute of Applied Physics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bylye Gody is the property of Cherkas Global University Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The main goal of any modern production of long products is to ensure the required quality of finished products. One of the important quality indicators, along with mechanical and technological properties, is the quality of the rolled metal surface. The article presents the results of experimental studies of the composition of high‑temperature diffusion oxides formed on the surface of artificially deposited defects under various conditions of temperature exposure using the microrentgenospectral method on a scanning electron microscope with an energy dispersive microanalyzer. The characteristic features in terms of the percentage and presence of certain chemical elements in the scale of various steel grades have been established.

Introduction. The production of modern technologies should take into account a comprehensive analysis of energy, biotechnological and thermophysical phenomena. The main processes in food technologies are the processes of heat and mass transfer, which need to be intensified. Aim of the Article. The aim of the work is studying the mechanisms and modeling the kinetics of heat and mass transfer in the microware field in the technologies for complex processing of food raw materials. Materials and Methods. The combination of thermal, hydrodynamic and diffusion driving forces with their coordinated action is able to solve problematic issues of processing raw materials, primarily food. Using the principles of the similarity theory, there is proposed a dimensionless complex – the number of energy action, which reflects the influence of the electromagnetic field. Results. Direct, targeted energy supply to the liquid phase of raw materials makes it possible to obtain a solid phase in the apparatus. These are fundamentally new features for the dehydration process. Boil-off rates at constant electromagnetic field intensity depend only on the solvent type. As a result of processing all experimental points, a criterion equation was obtained, it establishes the dependence of the energy action number on the dimensionless pressure and the dimensionless heat of the phase transition. Discussion and Conclusion. There are developed a new class of heat and mass exchange equipment ‒ electrodynamic apparatuses. The experimental results suggest that the flow from capillaries and nano-capillaries is initiated much faster when organizing the processes of targeted energy delivery with the involvement of pulsed microware field. An important advantage of electrodynamic extractors is the possibility of obtaining polyextracts. Food technologies with targeted energy delivery during evaporating, drying and extracting are resource- and energy-efficient and ensure full preservation of raw material potential.

The diffusion processes regularity in the reaction crucibles of the iron-tin system during their electrothermal treatment was studied by the numerical simulation methods. The effect of current density and temperature on the processes of heat and mass transfer in the reaction zone has been studied. Numerical simulation was performed by the finite element method. The developed model includes mechanical, thermal, electrical and chemical processes during the electrothermal treatment of the iron-tin system in the reaction crucible, taking into account the distribution of components under various processing conditions of the reaction crucible. A comparative analysis of the calculated data on the diffusion of tin into iron under conditions of long-term exposure to high temperatures without the application of an electric voltage and when the reaction zone is heated by passing a high-density electric current is performed. A picture of the distribution of mass fractions of components depending on the type of impact is obtained. The penetration depth of the interacting components was determined and the intensity of the mass transfer processes was assessed. The regularities of heat and mass transfer in the system of iron and tin with a change of the process initial parameters are established. The model was verified by comparing the simulation results with the data of full-scale experiments on control samples. The research results can be used to predict the conditions for obtaining new functional materials.

The work is devoted to an experimental study of the process of dissolution of a magnetic fluid in a nonmagnetic solvent under the action of a uniform magnetic field. It is experimentally established that in a volume of magnetic fluid surrounded by a miscible solvent fluid, under the action of a uniform magnetic field, a mechanical movement arises, triggering deformation of this volume. Initially, the axisymmetric volume of the fluid takes an ellipsoidal shape, lengthening along the magnetic field direction. The main reason for this movement is the pressure differences in the magnetic fluid, caused by jumps and nonuniformities of the magnetic field at the interface between magnetic and nonmagnetic media. Simultaneously with the mechanical motion, the diffusion dissolution of the magnetic fluid occurs, which is also accompanied by the motion of the diffusion front at the interface between the fluids. The concentration gradients of magnetic particles that arise in this case cause gradients of the magnetization of the fluid and, as a consequence, gradients of the magnetic field intensity. Together, this triggers the appearance of a bulk magnetic force in the magnetic fluid, and the pressure gradients associated with it. The main regularities of this process have been established, viz. the dependence of change of the geometric characteristics of the volume and its deformation rate on time. It is shown that at the initial stage of the process, the rates of mechanical movement of the boundaries of the magnetic fluid volume are much higher than the rates of movement of the diffusion front. Thus, the initial rate of mechanical elongation of the droplet under the experimental conditions is 0.25 mm/min, and the diffusion front rate is 0.08 mm/min. Over time, these processes slow down and stop when the volume of the magnetic fluid is completely dissolved. Herewith, the mechanical elongation of the drop is the first to stop and, in the case under consideration, takes about ten minutes.

The sugar industry in Russia plays a huge role in ensuring the country’s food security and is a strategic industry. Of the 90 sugar factories in Russia today, a third of the factories are closed due to unprofitability associated with the high cost of sugar production due to low feed capacity. The raw material for sugar production is sugar beet, mainly domestically produced. The locations of most sugar factories are small municipalities, for which they are the town-forming enterprises. For the revival of closed sugar factories, it is necessary to increase their capacity, which is difficult to do due to the fact that in the diffusion section of each sugar factory there is one large-sized imported diffusion apparatus of a mechanical type, which does not allow increasing capacity in any other way than purchasing a new, more high-performance expensive imported diffusion apparatus of a mechanical type. In the current conditions of uncertainty and disruption of trade relations with other countries, new suppliers of high-performance diffusion apparatus are needed in Russia itself, the apparatus of which would at least not be inferior to the Western apparatus. The Russian company Ingehim has developed a diffusion pulsating apparatus (DPA) without mechanical movable transporting devices, which reduces energy consumption, operating costs and lowers quality requirements for sugar beet chips. The test results obtained using an experimental unit showed a higher quality of the diffusion juice. The lightness of the juice was found to be much higher compared to juices produced in conventional diffusion apparatus, and the juice purity was found to be 5% higher at a comparable solids content, resulting in an additional amount of sugar produced per year, allowing for a faster return on investment.

Copyright of Electronic Processing of Materials / Elektronnaya Obrabotka Materialov is the property of Institute of Applied Physics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background and Objectives: The two-phase gas-liquid foams have been an active object of research over the past few decades. Usually, during the coarsening of the foam such physical processes as a foam syneresis (the liquid drainage along the Plateau channel and the bubble walls under the gravity), an Oswald ripening of the gas bubbles, and their coalescence are investigated. Another process that accompanies the aging of gas-liquid foams is the evaporation of the liquid component of the foam that is insufficiently described in the literature. Each of these processes is characterized by its own kinetics. The major factors that determine the dynamic and kinematic characteristics of the foams are the volume fraction of the liquid in the foam, the rheological properties of foam films, the average thickness of films between the gas bubbles, and the dispersion of the system. The modern methods for the diagnostic of the structural rearrangements and the foam aging do not allow studying the evolution of the three-dimensional foams in the real time. In this work, a comparative analysis of the behavior of the time correlations of the intensity fluctuations of the scattered by the liquid foam laser radiation on long time scales is carried out for the case of the system with mass transfer of the liquid component due to its partial evaporation and the isolated system. Such studies play an important role in the development of the coherent-optical methods for the morphofunctional diagnostic of the micro- and nanostructured multiphase systems in the real time. Materials and Methods: The analysis of the evolution of the isolated and “open” liquid foams during their aging is carried out by use of the speckle correlometry method. Two series of the experiments were performed with an isolated system and an “open” system at a temperature of 24°C. Results: The correlation time of the intensity fluctuations of the radiation scattered by the medium was calculated from the normalized correlation function, based on the criterion of its decay by a factor of e. The dependences of the correlation time of the intensity fluctuations on the aging time for isolated and “open” systems are obtained. A phenomenological model to describe the increase in the correlation time of intensity fluctuations is proposed. Within the framework of the model, the experimental data agree with the model data for an isolated foam and correlates with a power law with an exponent equal to 1.5. Conclusion: A speckle-correlation analysis as method for the analysis of the local instabilities caused by the structural rearrangements in the foams under the coarsening was considered. The phenomenological model, that establishes the relationship between the correlation time of the intensity fluctuations of the laser radiation scattered by the foam and the aging time of the foam, is proposed. The obtained results may be useful for the further development of laser methods for the diagnostic of nonstationary multiphase systems with a complex structure and dynamics.

The currently known main mechanisms of martensitic transformation of austenite in steel during cooling, physical models, and schemes of shear rearrangement of the iron crystal lattice during γ→α transformation under the action of internal stresses are considered. An analysis of the available kinetic model of the shear transformation of austenite in steel is carried out considering the influence of stresses. As shown, for the transformation of retained austenite into martensite, two main conditions have to be fulfilled. The first one is thermodynamic condition due to decreasing the temperature of the steel down to the temperature of the end of the transformation of retained austenite. The second condition is kinetic one due to increasing the level of internal stresses in austenite, the cooling rate at the final treatment stage or mechanical impact. To calculate the effect of stresses on the transformation of retained austenite in steel, a new equation is proposed that takes into account the minimum stress required for a crystallogeometrically ordered displacement of iron atoms during the formation of martensite. As shown, the effect of alloying elements and cooling rate on the temperature of the beginning and end of the austenite transformation can be calculated using the relations given in the article. To calculate the quantity of martensite formed depending on the transformation temperature, an improved Koistinen–Marburger equation is suggested. This equation takes into account not only the temperature of the beginning, but also the temperature of the end of the austenite transformation, i.e., increases the accuracy of the obtained result.

The article suggests ways to increase the efficiency of dyeing cotton fabrics with natural dyes by increasing the degree of extraction of the coloring substance from natural plant raw materials and facilitating the diffusion of the dye into the structure of cellulose fiber. Experimental studies of the technology of ultrasonic processing of natural plant raw materials have been carried out in order to increase the degree of extraction of the coloring substance from the working solution. The dependences of the optical density of dye solutions on the modes of ultrasonic treatment are determined. It is shown that the generator power is a factor affecting the degree of output of the coloring pigment into the solution, the duration of voicing has little effect on the analyzed parameter. The effectiveness of the preliminary enzyme preparation of cotton fabrics has been proven in order to facilitate the diffusion of the coloring substance into the cellulose fiber and increase the degree of dye selection from the dye solution. A comparative analysis of colored tissue samples obtained with the sound power of natural plant raw materials of 30 W for 20 minutes, in terms of brightness and color saturation, was carried out. The optimal technological modes of ultrasonic processing of plant raw materials have been determined the generator power is no more than 60 watts, the duration of ultrasonic treatment is 20 minutes. A schematic diagram of the preparation and dyeing of cotton fabrics with natural plant dyes for the creation of highly environmentally friendly textile products – ecotextile – is proposed. В статье предложены способы повышения эффективности крашения хлопчатобумажных тканей природными красителями за счет увеличения степени экстрагирования красящего вещества из природного растительного сырья и облегчения диффузии красителя в структуру целлюлозного волокна. Проведены экспериментальные исследования технологии ультразвуковой обработки природного растительного сырья с целью повышения степени экстрагирования красящего вещества из рабочего раствора. Установлены зависимости оптической плотности красильных растворов от режимов ультразвуковой обработки. Показано, что фак- тором, влияющим на степень выхода красящего пигмента в раствор, является мощность генератора, продолжительность озвучивания слабо влияет на анализируемый параметр. Доказана эффективность предварительной ферментной подготовки хлопчатобумажных тканей с целью облегчения диффузии красящего вещества в целлюлозное волокно и повышения степени выбирания красителя из красильного раствора. Проведен сравнительный анализ окрашенных образцов тканей, полученных при мощности озвучивания природного растительного сырья 30 Вт в течение 20 мин, по показателю яркости и насыщенности цвета. Установлены оптимальные техно- логические режимы ультразвуковой обработки растительного сырья – мощность генератора не более 60 Вт, продолжительность озвучивания 20 мин. Предложена принципиальная схема подготовки и крашения хлопчатобумажных тканей природными растительными красителями для создания высокоэкологичной текстильной продукции – экотекстиль.

In this work, the effect of proton irradiation on the change in the structure of silicon samples doped with platinum was studied. The samples were irradiated with protons at a dose of 9×1014 cm-2 with an energy of 600 keV and a current of 1÷1.5 μA. To determine the change in the structure after irradiation, the methods of X-ray diffraction and atomic force microscopy were used. The obtained results indicate that doping with platinum does not lead to a modification of the cubic crystal structure of silicon, but only to minor changes in the structural characteristics and surface morphology. In this case, proton irradiation of a silicon single crystal with a dose of 9.0×1014 cm–2 with an energy of 600 keV leads to the formation of defects without the formation of an amorphous near-surface layer.