http://repository.enu.kz/handle/enu/15474 2026-04-06T07:11:26Z http://repository.enu.kz/handle/enu/30995 Wet Chemical Synthesis of AlxGa1−xAs Nanostructures: Investigation of Properties and Growth Mechanisms Suchikova, Yana; Kovachov, Sergii; Bohdanov, Ihor; Konuhova, Marina; Zhydachevskyy, Yaroslav; Kumarbekov, Kuat; Pankratov, Vladimir; Popov, Anatoli I. This study focuses on the wet chemical synthesis of AlxGa1−xAs nanostructures, highlighting how different deposition conditions affect the film morphology and material properties. Electrochemical etching was used to texture GaAs substrates, enhancing mechanical adhesion and chemical bonding. Various deposition regimes, including voltage switching, gradual voltage increase, and pulsed voltage, were applied to explore their impact on the film growth mechanisms. SEM analysis revealed distinct morphologies, EDX confirmed variations in aluminum content, Raman spectroscopy detected structural disorders, and XRD analysis demonstrated peak position shifts. The findings emphasize the versatility and cost-effectiveness of wet electrochemical methods for fabricating high-quality AlxGa1−xAs films with tailored properties, showing potential for optoelectronic devices, high-efficiency solar cells, and other advanced semiconductor applications. 2024-01-01T00:00:00Z http://repository.enu.kz/handle/enu/30994 USING COAL FLOTATION WASTE AS A HEAT-INSULATING BILLING FOR THE HEAD PART OF A FORGING INGOT Ibraev, I.K.; Ibraeva, O.T.; Aitkenov, N.B.; Sakipov, K.E. The experience of using coal flotation waste as a weakly exothermic insulating backfill for insulating the head part of forging dead-melted steel ingots is presented. It has been shown that when using weakly exothermic fills based on single-component fills in the form of coal flotation waste, it is possible to reduce the chemical heterogeneity of the ingot by producing a closed shrinkage cavity, which allows halving heat loss and depth of penetration of shrinkage looseness into the body of the ingot, reducing the segregation of impurities, compacting the head part of the ingot and increasing the yield; moreover, the profitable part of the ingot is more dense and less contaminated with nonmetallic inclusions. The studied patterns of the formation of a closed shrinkage cavity with a dense “bridge” in the head part of a dead-melted steel ingot made it possible to develop and implement a technology for casting large forging ingots of sufficiently high quality using weakly exothermic heat-insulating materials based on metallurgical waste (coke screenings, coal flotation waste). 2024-01-01T00:00:00Z http://repository.enu.kz/handle/enu/30993 Using semantic paradigms as tools for foreign language teaching: theory and practice Mauitbekova, Aisulu; Bulatbayeva, Kulzhanat Relevance. The relevance of the aforementioned study topic is motivated by the progressive activity of mankind in terms of the development of the information society, the growing demand for foreign language skills and the problem of learning a foreign language, as the large amount of information that needs to be assimilated certainly slows down this process. Purpose. The purpose of this study is to evaluate the effectiveness of using semantic paradigms as tools for foreign language teaching; the existing developments that have been used to date and the results of their use. Methodology. The methodological approach is based on an analytical study of the use of semantic paradigms (examples are given of the use of semantic frequency dictionaries to increase the efficiency and speed of learning a foreign language) as tools for foreign language learning. Results. The main results that were obtained during the study can be considered: the evaluation of the effectiveness of the introduction of semantic paradigms and interaction with native speakers in the context of foreign language learning, the prospects of semantic paradigms in foreign language teaching among higher education representatives, along with the formed conclusions on how the use of semantic paradigms affects the quality of acquired knowledge. Conclusions. The results of this scientific research, as well as the conclusions formulated during its conduct, are of the greatest importance for people who pursue the goal of learning a foreign language for personal and professional purposes and for foreign language teachers who may use effective, non-traditional teaching methods in their practice. Furthermore, psychologists whose work centres on science and theory can broaden the scope of their studies on the example of this investigation. 2024-01-01T00:00:00Z http://repository.enu.kz/handle/enu/30992 Unveiling the Structural and Optical Properties of MgAl2O4 Single Crystals Irradiated by Swift Heavy Ions Akilbekov, Abdirash; Kiryakov, Arseny; Dauletbekova, Alma; Aralbayeva, Gulnara; Akylbekova, Aiman; Ospanova, Zhulduz A synthetic single crystal of magnesium-aluminate spinel was irradiated perpendicularly to the (111) plane with swift heavy xenon ions with an energy of 220 MeV. The modified layer was attested based on Raman scattering spectra recorded while focusing on the surface. A decrease in surface crystallinity was observed, reflected in the changes in fundamental optical characteristics such as the band gap and the energies of static and dynamic disorder. In this study, we demonstrate, along with the modification of optical characteristics and the formation of a disordered layer, the creation of new optically active centers. The luminescent properties of these centers were analyzed. The effect of temperature flare-up in the 3.4 eV band of the excitation spectrum was determined. The low sensitivity of Cr3+ luminescence to SHI is demonstrated. 2024-01-01T00:00:00Z