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Structural, electric, and optical studies of silicon-on-sapphire substrates with silicon and hafnia nanolayers have been carried out depending on the substrate thickness. It is shown that the biaxial tensile stress induced in the intermediate HfO₂ layer - as a result of the heat treatment of such structures, due to the large difference in the thermal expansion coefficients between the layers of silicon, sapphire and hafnium dioxide, - stimulates the current hysteresis in the SOS-pseudo-MOSFET channel. It is found that a decrease in the mechanical stress in hafnium dioxide leads to an increase in the coercive field and ferroelectric switching at low fields in hafnia nanolayers.

Layered SnSe₂ 50 and 30 nm thick films are grown using in situ reflection electron microscopy on Si(111) and Bi₂Se₃(0001) substrates. The growth of films proceeds by a multilayer mechanism with the formation of pronounced mounds. The height of the atomic steps is measured by atomic force microscopy (AFM) and amounts to 0.6 nm, which corresponds to the thickness of the SnSe₂ layer. The ex situ AFM image of the SnSe₂ film grown on Si(111) shows a high concentration of screw dislocations in the film (~12 μm^-2) and the presence of domains with triangular step faceting having two types of orientation with respect to the substrate. It has been found that the SnSe₂ growth on the single crystal Bi₂Se₃(0001) surface occurs with the formation of hexagonal-faceted mounds equally oriented with respect to the substrate. The mounds are formed by a multilayer mechanism both in the places where screw dislocations come to the surface and due to periodic nucleation of 2D islands on the highest terraces. The sizes of the highest terraces are up to 1 μm. The spectra characteristics of the films are obtained using the Raman scattering method on both substrates and correspond to the 1T-SnSe₂ phase in both cases.

An interband photoluminescence (PL) of structures with multiple quantum wells (MQWs) with different contents of Ge and Sn has been obtained. The peak position on the PL spectra obtained from Ge_0.93-xSi_xSn_0.07/Si MQWs is shifted to longer wavelengths with the Ge content increase in the solid solution and is observed in the energy range of 0,85-0.68 eV for the Ge content from 30 to 78%. Thus, the peak shift over the wavelength from 1,46 μm to 1,82 μm was observed, and the total spectral range of MQWs luminescence covered by these structures was 1,3-2,1 μm. An even more significant shift of the MQWs PL peak to the long wavelength region is achieved by increasing the Sn content. The increase in the Sn content from 7% to 14% at a constant 30% Ge content leads to the peak shift from 0,85 eV to 0,75 eV. A simultaneous increase in the content of both tin and germanium in the solid solution (to 14% and 79%, respectively) makes it possible to obtain the PL peak with the energy of 0,58 eV, which corresponds to the emission wavelength of 2,14 μm. A sharp “red” shift in the position of the PL peak with the temperature increase is found. Its value is up to 50 meV at the change of the heating sample temperature from 11 K to 60-80 K. Such a significant shift in the position of the MQWs PL peak is explained by the model assuming that charge carriers are randomly localized on spatial inhomogeneities of the MQWs at low temperatures, whereas they are redistributed and transferred to a thermodynamically equilibrium state with the lowest energy as the temperature increases.

The kinetics of reflectivity signals from nanostructures including an equal number of quantum wells with an identical composition In_xGa_1-xAs (x=0.32) with GaAs barriers of 2, 4, 6, and 8 monolayers grown over a semiconductor reflector under identical conditions are investigated by the pump-probe technique. The tendency of recovery time shortening for thinner barriers is found. The prospects of further research and practical application of quantum wells coupled via charge carrier tunneling are under consideration.

An analysis of the structure of as-deposited films of nonstoichiometric germanosilicate glasses and the transformation of their structure under annealing is carried out using the Raman spectroscopy and IR spectroscopy. It is shown that the structure of the films is stable up to a temperature of 350 ^oC; under annealing beginning from 400 ^oC, amorphous germanium clusters are formed in the films. On the basis of these films, metal-insulator-semiconductor structures are fabricated, and prospects for their use in memristors and photodetectors are demonstrated.

This work demonstrates that digital technologies can be successfully applied to image analysis and prediction of the properties of functional materials. As an example, a new method is used to rapidly identify the crystallographic orientation parameters in multicrystalline silicon. The proposed method is based on machine learning technologies. The analysis of textured multicrystalline silicon wafers is carried out using the original single-crystal grain clustering algorithm, and the crystallographic orientation parameters are identified using a neural network model. The principle of identification is based on the correlation of the contrast of the macrostructure display associated with the reflective features of the grains and their orientation parameters. The architecture of the neural network - a multilayer perceptron - is chosen taking into account the restrictions on the number of input data. However, in conjunction with the algorithm, the optimal amount of training data satisfies the requirements of the neural network training process and ensures high efficiency in identifying orientation parameters on scanned images of textured multicrystalline silicon wafers.

The field dependence of the magnetization of a silicon nanosandwich, observed at room temperature, demonstrates a very complex character. The dependence is formed by the main contribution of the quantum magnetic effect, which is interpreted as the de Haas - Van Alphen effect with integer and fractional filling factors. Based on the previously found two-dimensional carrier density, the critical fields for the corresponding filling factors are calculated. Modeling of the de Haas - Van Alphen oscillations at a high temperature (T = 300 K) is performed according to a given distribution of the energy density of states of a silicon nanosandwich in the vicinity of Landau levels. The computational procedure is implemented on a supercomputer. The dependence of the carrier effective mass on the strength of the external magnetic field, previously discovered by us, is taken into account.

This work presents the Monte Carlo simulation results of gold droplet movement over a vicinal Si(111) surface during the gold deposition. The behavior of gold droplets on a singular silicon surface with (111) and (100) orientations is considered. It is found that the directional droplet motion on the vicinal Si(111) surface is caused by the asymmetry of lateral facets at the liquid-crystal interface. The asymmetry of lateral facets is caused by the presence of steps on the vicinal Si(111) surface. The reason for the gold droplet movement is the silicon substrate dissolution in the tendency to reach the Au-Si melt equilibrium concentration in the droplet bulk. The kinetics of Au-Si droplet movement on the silicon surface is analyzed.

Introduction. Socio-ideological and socio-structural factors consist in that a rural small school is not only an educational institution, but also a social institution with a multidimensional and concentrated influence on the rural areas development, solving demographic problems, strengthening youth, improving cultural and professional level of rural society. In this regard, the issues of centralized resource support and professional development of newly-hired teachers of small rural school are being updated. Professional support programs (induction programs) for novice teachers in small rural schools are the key ones in the modernizing education strategy in foreign countries14. Methodology. A comparative analysis of the content of induction support programs for small rural schools teachers in foreign countries is used as a methodological basis. Discussion. The international experience of professional supporting young teachers of small rural schools is presented. The tasks and characteristic features of induction programs’ content to support teachers of small rural schools in foreign countries are revealed. Pedagogical and methodological means that provide compensation for deficits in the educational process in small rural schools in foreign countries are analyzed. Conclusion. On the basis of a comparative analysis, data are presented on possible programs to support small rural schools in foreign countries, natural conditions and opportunities for building a career route, professional and personal development, psychological microclimate and well-being of the newly-hired teachers.

Introduction. The task of Russia’s achieving technological sovereignty is connected with the necessity of training of mathematically educated scientists and engineers. This paper is intended to contribute to the discussion of ways to correct the situation with mathematical education. The thesis is emphasized that a simple return to the ideas and methods of mathematical education in the USSR will not solve the problem, since the tasks of mathematics, the areas of its applications have changed, social and cultural values have changed, students and their teachers have changed. All this requires discussion of some ideas regarding the dynamics of the movement of mathematical knowledge. The purpose of this paper is to analyze the current state of mathematics teaching in schools and universities, to identify the problems of modern education and outline the prospects for their solution. Methodology. The need to expand the context of the topic under discussion required access to general philosophical questions about the universal mechanisms and patterns of human cognitive activity within the epistemological approach to understanding mathematics, regardless of its specific forms and types. For this purpose, the methods of historical and comparative analysis are used in the study of scientific and methodological literature. Discussion. From the point of view of the epistemological approach, the issues of constructive expansion of knowledge about mathematical education and the connection of its characteristic features with the ontology of social cognition are revealed. The role and significance of the “human dimension of mathematical materialˮ are revealed. Conclusion. Recognizing the epistemology of education as a methodological regulator in the development of algorithms for evidence-based reasoning and the desire to revive, spiritualize the “dryˮ mathematical reality, the necessary provisions have been developed for the constructive expansion of knowledge about mathematical education in connection with the ontology of social and individual cognition.