Eurasian Journal of Physics and Functional Materials

Advanced search
Vol 4, No 3 (2020)
186-200 125

This article is devoted to the description of the properties of the lightest nuclei with a large excess of neutrons. Light nuclei have always attracted attention due to the wide variety of their properties. While the structural characteristics of medium and heavy nuclei vary fairly smoothly, only single deviations are observed, the structure of light nuclei varies sharply, two neighboring light nuclei are often completely different from each other. This, on the one hand, makes their study a very interesting task, and on the other hand it makes it difficult to identify common trends. Our interest in light neutron-rich nuclei is connected with the desire to observe the characteristic features of nuclei overloaded with neutrons.

201-212 131

The three-body wave function built on the basis of the Gaussian function, calculated using the three-body Hamiltonian with the Pauli blocking operator is studied. As an example, the wave function of the ground state of the 9 Be was taken. Analytical expressions are presented for the overlap matrix elements of the basis function for both basic and alternative set of relative Jacobi coordinates. The correlation densities of the wave function are calculated and illustrated depending on the set of orbital quantum numbers.

213-225 159

Simulating with GEANT4 of anti-Compton shield containing eight BGO scintillators that works on anti-coincidence with HpGe detector was presented. The coefficient value of Compton tail suppression on 60Co spectrum was taken by simulating and from experiment. Comparing results of experimental data with simulating were presented. The influence of anti-coincidence inclusion on the detector efficiency was determined with simulation.

226-233 124

Using the tagged neutron method at the "TANGRA" facility at Frank Laboratory of Neutron Physics of the Joint Institute for Nuclear Research based on the ING-27 standard neutron generator, a study of the 14.1 MeV inelastic neutron scattering reaction on different nuclei was carried out. The angular distributions of g-quanta accompanying inelastic neutron scattering on atomic nuclei were measured. This article presents a GEANT4-based program that allows calculating the interaction of fast neutrons with matter and simulating the experiment and also presenting the results of the experiment in a convenient and visual form. Using the written program, optimal target parameters were determined. The algorithm used by the program is given in this work. The general description of the experimental installation, data collection and processing systems is given.

234-241 120

The paper presents the results of changes in the strength characteristics of thin film coatings based on compounds of copper-bismuth, copper-magnesium, copper-nickel. The dependences of the influence of the phase composition on the strength characteristics, such as the coefficient of friction, bending strength and impact coefficient, are established. The effect of irradiation with helium ions with a high radiation dose of 1015-1017 ion/cm2 on the strength characteristics is evaluated. It is shown that an increase in the radiation dose leads to a decrease in strength properties due to the appearance of a large concentration of defects in the structure.

242-248 160

In this work, consider the aspects of obtaining powder coatings that possessing certain working properties obtained by detonation spraying. Experimental research were carried on the effect of technological parameters of the detonation spraying process on the phase composition and properties of Ti-Si-C coatings. It is determined that when the volume of filling the detonation barrel with an explosive mixture increases to 70% in the detonation wave flow, the Ti3SiC2 powder partially decomposes into TiC consequently the high-speed shock interaction of heated to high temperatures. Installed that when filling the barrel with an explosive mixture of 50% and 60%, a low extent of decomposition of Ti3SiC2 powder can be achieved. It is determined that an increase in the volume content of the TiC phase in the composition of coatings bring to a decrease in the hardness of the Ti-C-Si coating.

249-254 151

In work considers the results of studies of the phase composition and mechanical-tribological properties of Ni-Cr detonation coatings obtained at different values of the volume of filling the detonation barrel with an explosive acetylene-oxygen mixture. Analysis of the obtained experimental results indicates that the phase composition and properties of detonation coatings strongly depend on the technological parameters of spraying. When the barrel is filled with an explosive gas mixture of 40%, the coating is not dense enough, with noticeable boundaries between individual particles, which may be the result of insufficient heating and acceleration of the particles of the sprayed powder. It is determined that when the volume of filling the detonation barrel with an explosive mixture is up to 60%, there is a widening and a decrease in the intensity of the main peaks. Higher values of microhardness were obtained at 50% filling of the barrel. The results of tribological tests of coatings showed that the coating applied when filling the detonation barrel with an explosive mixture of up to 60% has a lower coefficient of friction than other coatings.

255-260 167

Nano-dimensional crystalline cadmium sulfide is a semiconductor that exhibits size-dependent opto-electronic properties, determined by the effects of quantum confinement. Due to these effects, it is possible to adjust the optical properties of the final cadmium sulfide clusters by varying their size. In this work we report the results of a theoretical study of CdS nanoparticles with the methods of the density functional tight-binding (DFTB) and the time-dependent density functional theory TD DFT. The calculations of the electronic absorption spectra of CdS crystals were performed on cadmium sulfide nanoparticles with an amount of from 5 to 137 atoms. The DFTB method was used for the structural optimization of the studied nanoparticles. The optimization results showed that the clusters will be a wurtzite structure and the geometrical parameters of the structure are close to the known experimental data for a CdS crystal. For the obtained optimized structures, the electronic absorption spectra were calculated by the linear response methods in the DFTB approximation and the time-dependent density functional theory of the TD-DFT approximation. It is shown that the data obtained by the DFTB method are close to those that can be obtained using DFT calculations for cadmium sulfide clusters. Especially good agreement is obtained when using large clusters with small values of the dipole moment.

261-267 132

A ternary nanocomposite material based on TiO 2 , graphene oxide and core-shell nanostructures of Ag/TiO2 composition was obtained by a two-step hydrothermal method. The formation of a dual TiO2-GO nanocomposite was confirmed by Raman spectroscopy data, where the nanocomposite spec- tra contain peaks characteristic of both TiO 2 and graphene oxide. Studies of electrophysical character- istics have shown that the addition of plasmon nanoparticles leads to an improvement in the charge-transfer characteristics of the synthesized material. This is due to the fact that the charge transfer resistance of a ternary nanocomposite material TiO2-GO-Ag is noticeably lower than for pure TiO 2 ( 13 times) and TiO2-GO nanocomposite ( 3 times). In addition, the prescence of Ag/TiO2 core-shell nanostructures in the TiO2-GO nanocomposite material leads to an increase in the efficiency of conversion of incident light into photocurrent, which will be resulted in the growth of photocatalytic activity of synthesized materials.

ISSN 2522-9869 (Print)
ISSN 2616-8537 (Online)