Density functional theory (DFT) is used to calculate the density of phonon energy states and the phonon spectrum at symmetric points and lines of the Brillouin zone. Using the phonon spectrum and the phonon density of states, the molar entropy, the internal energy of phonons, and the temperature dependence of the heat capacity at constant volume for CdGa2Se4 in the range 0÷400 K were calculated from first principles. It is shown that the molar heat capacity varies according to the cubic Debye law T3 at temperatures below 6,1 K. The calculated frequencies of optical phonons were compared with the experimentally determined frequencies from the infrared absorption (IR) and Raman spectra (R), and it was shown that they are in good agreement.

A technique has been developed for obtaining 3d-metal/por-Si at electrochemical deposition and co-deposition of iron and cobalt into a porous silicon matrix Based on the results of the experiment, it can be concluded that the chemical deposition of various metals of the iron group has a similar effect on the composition of the porous layer. With the joint deposition of iron and cobalt in porous silicon of the n type, cobalt promotes a deeper penetration of iron into the porous layer. The influence of the deposited metal on the position of the peak of the photoluminescence intensity of 3d-metal/por-Si nanomaterials is shown.

The specific electrical conductivity in TlInTe2 and TlInTe2-Te (4at.%) crystals were investigated in the range of 100-300 K and 10-102 V/cm in the parallel and perpendicular directions of the chain plane. It was determined that the presence of more than stoichiometry of Te-atom in the octahedral cavities between thallium atoms enhances the ion-covalent bond under the cation lattice and reduces the conductivity in the direction of the c crystal axis in the TlInTe2 – Te system. This leads to a partial decrease in the anisotropy of the conduction at Ek < 40 V/cm values of electric field intensity, and the sharp increase at high field intensities. The activation energies of energy levels in parallel and perpendicular directions to InTe4 chains were determined from σ~f(T) dependencies as 0,12; 0,35 eV and 0,10 eV; 0,32 eV, respectively.

The conformational possibilities of the exorphin B4 molecule were studied by the method of theoretical conformational analysis. The potential function of the system is chosen as the sum of non-valence, electrostatic and torsion interactions and the energy of hydrogen bonds. The spatial structure of the exorphin B4 molecule was calculated based on the low-energy conformations of the corresponding amino acid residues. It has been shown that the spatial structure of the exorphin B4 molecule can be represented by thirteen low-energy conformations. The low-energy conformations of the molecule, the values of the dihedral angles of the main and side chains of amino acid residues were found, the energy of intra-and inter-residual interactions was estimated.

In the present work nanocomposites based on PVC+Fe3O4 obtained by solution blending method. The structure of the nanocomposite based on PVC+Fe3O4 was studied by X-ray diffraction method. The XRD measurement prove formation of the nanocomposite based on the PVC polymer and iron-oxide nanoparticles. The change in the resistivity of nanocomposites based on PVC+Fe3O4 under the influence of a magnetic field has been studied. The data shows that the value of the negative magnetoresistivity decreases with repeating measurem This decrease is associated with the magnetic memory of the sample. Temperature dependence of the samples’ resistivity shows that is stable for 60-160℃ temperature diapason. This result supports the high potential of PVC+10%Fe3O4 samples as magnetoresistive sensor.

It is theoretically proved that the excited wave in two-valley semiconductors is growing. It is indicated that the directions of external fields play an essential role for the appearance of growing waves in the sample. It is shown that oscillations can occur at certain values of the sample dimensions L_x,L_y,L_z. Analytical formulas for the frequency of the growing waves are obtained. The interval of variation of the external electric field in a strong magnetic field μH>>c has been determined.

We examine the longitudinal momentum densities within extended objects of the momentum component P^+, and find relativistically exact connections to Fourier transforms of electromagnetic form factors with respect to the momentum transfer in the transverse direction. The electromagnetic form factors are obtained by the second moments of generalized parton distributions.

Electrochemical deposition of thin film silicon p−n junction in molten salt has been successfully demonstrated for the first time. Silicon p−n junction film can be directly produced from inexpensive silicates/silicon oxide precursors through two-step electrodeposition process, which makes this technique attractive for low-cost manufacturing for silicon solar cells. Although the photovoltaic performance is currently modest, there is still a big margin for improving the overall film quality.

A new method for studying semiconductor multilayer structures used in the manufacture of optoelectronic devices, based on the analysis of photoluminescence spectra under two-quantum excitation, is described. This method makes it relatively easy in several cases to determine the band gap of individual layers, their thickness, and the degree of doping with impurities.

The behaviour of low-lying 0+ levels, transition rates E2, and cross sections (p,t) of direct reactions was studied based on the SU(5) subgroup. Exploiting this subgroup was received simple analytic expressions for the transition matrix elements E2 and cross sections (p,t) reactions. It is proposed to describe the collective vibrational degree of freedom by an algebra SU(5), which is formed by five components. It should be noted that the considered finite-dimensional systems differ from the geometric description, in which the number of bosons is N→∞.