http://repository.enu.kz/handle/enu/10457 2026-04-03T23:49:04Z http://repository.enu.kz/handle/enu/10898 Thermal conductivity of new nanocomposite superionic semiconductors K0.01Cu1.96S, K0.02Cu1.95S, K0.03Cu1.94S, K0.04Cu1.93S, K0.05Cu1.94S Kubenova, M.M.; Balapanov, M.Kh.; Ishembetov, R.Kh.; Kuterbekov, K.A.; Almukhametov, R.F.; Bekmyrza, K.Zh.; Kabyshev, A.M.; Palymbetov, R.Sh.; Taimuratova, L.U. In this work, we investigated the effect of nanostructuring on the thermoelectric and thermal properties of nonstoichiometric solid splavs doped with copper sulfides with potassium. The synthesized alloys K0.01Cu1.96S , K0.02Cu1.95S , K0.03Cu1.94S , K0.04Cu1.93S , K0.05Cu1.94S are nanocomposite. The crystallite sizes of the synthesized powder, as estimated from the half-width of X-ray diffraction lines, range from 7 to 180 nm. Sample K0.01Cu1.96S is a mixture of phases consisting of chalcocite Cu2S (82%), jarleite Cu1.96S (12%), anilite Cu1.75S (6%). The composition of samples K0.02Cu1.95S and K0.03Cu1.94S includes the most common phases of copper sulfides - chalcocite Cu2S , jarleite Cu1.96S , digenite Cu1.80S . Samples K0.04Cu1.93S and K0.05Cu1.94S consist of jarleite Cu1.96S , digenite Cu1.80S and potassium copper sulfide KCu4S3 phases. In a practical sense, the extremely low thermal conductivity values (from 0.16 to 0.80 W/m · K) found in the range of 300–700 K for nanocomposite samples K0.02Cu1.95S and K0.03Cu1.94S are very favorable for achieving high thermoelectric figure of merit ZT material. 2023-01-01T00:00:00Z http://repository.enu.kz/handle/enu/10897 Computational scheme for breakup of 11Be on light targets Valiolda, D.S.; Janseitov, D.M.; Melezhik, V.S. We investigate the Coulomb breakup of the 11 Be halo nuclei on a light (carbon) target within nonperturbative time-dependent approach including the low-lying resonance 5/2+ of 11 Be (E= 1.232 MeV). We had found considerable contribution of the low-lying resonances ( 5/2+ , 3/2− and 3/2+ ) to the breakup cross section of 11 Be on a heavy ( 208 Pb) target at our previous calculations. The developed computational scheme is extended to study the breakup of 11 Be on a light target. This work is the initial step, where the convergence and accuracy of the computational scheme is tested. 2023-01-01T00:00:00Z http://repository.enu.kz/handle/enu/10896 Influence of surfactants on the formation and growth of cadmium telluride nanoplatelets Akhmetova, A.S.; Ospanova, A.K.; Yussupbekova, B.N.; Alibay, T.T. The article presents a comprehensive review of the current research on the use of surfactants in CdTe nanoplatelet synthesis, including a discussion of the various types of surfactants that have been used and their effects on nanoplatelet size, shape, and optical properties. Additionally, the article examines the mechanisms by which surfactants influence the growth and morphology of CdTe nanoplatelets, with a focus on the role of surfactant, size, and structure. Overall, this article provides a detailed analysis of the use of surfactants in the synthesis of CdTe nanoplatelets and highlights the potential for this approach to improve the performance of CdTe-based technologies. The dependences of the NPL absorption and photoluminescence spectra on acids used as surfactants are shown. The dependence of the shape and size of the NPL on the length of the surfactant ligand was found. 2023-01-01T00:00:00Z http://repository.enu.kz/handle/enu/10895 Electron-hole trapping centers in alkali metal sulfates with Dy3+ impurities Nurakhmetov, T.N.; Alibay, T.T.; Bakhtizin, R.Z.; Pazylbek, S.; Kainarbay, A.Zh.; Zhunusbekov, A.M.; Sadykova, B.M.; Tolekov, D.A.; Shamieva, R.K.; Nurpeissov, A.S. The Na2SO4 − Dy samples were obtained by slow evaporation method. The spectroscopic methods were used to study the mechanisms of formation of electron and hole trapping centers. Intrinsic recombination emission of 2.9–3.1 eV and impurity emission of 2.55 eV and 2.15 eV are excited at 4.0–4.5 eV. Intrinsic SO3−4 − SO−4 and impurity Dy2+ − SO−4 trapping centers were revealed. The local levels corresponding between the electron and hole trapping center are 4.0–4.5 eV. 2023-01-01T00:00:00Z