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Changes of the structure and phase composition occurring during the interaction of copper and its alloys in the solid-state phase with the liquid melts of indium, gallium and tin are considered. It is shown that the phase and morphological composition of interaction products depends on the relations between the rates of diffusion and the rates of reagent dissolution. Structural transformations that take place during contact melting and eutectic crystallization in the zones of indium - tin and indium - bismuth contacts are also considered. A hypothesis concerning the nature and microstructure of eutectics is proposed.

A local atomic structure around titanium positions in Ti-bearing hibonite (CaAl₁₂O₁₉) has been studied. The structural models of substitution of different substitution defects Ti-Al in hibonite by titanium atoms have been considered. Optimization of structural models of hibonite has been done by means of density functional theory calculations using pseudopotential approximation as implemented in VASP 5.3 code. Gibbs free energies analysis has shown that models of substitution of M2 and M4 aluminum positions by titanium atoms are the most probable. For the most probable structural models of Ti-bearing hibonite theoretical X-ray absorption near-edge structure (XANES) spectra near the titanium K -edge have been calculated. Significant differences in theoretical XANES spectra calculated for different structural models with non-optimized and optimized atomic structure have been demonstrated. Changes in the intensity of pre-edge structure of Ti K -XANES spectra for different substitution models of aluminum by titanium have been observed which relate to different titanium coordination in structural models. Energy shift of spectral features towards lower energy for optimized models implies increase of interatomic distances in local surroundings of Ti absorbing atoms.

The behavior of Li-exchanged natrolite Li_1.92Na_0.10[Al_2.02Si_2.98O₁₀]x2H₂O at compression in penetrating (water-containing) medium was studied by in situ synchrotron powder diffraction in diamond anvil cell up to 2.5 GPa. Within 0-1.3 GPa the compression is almost isotropic, and upon the further pressure increase the sample undergoes additional hydration, leading to abrupt volume expansion by 22%, a record value for natrolite. In the proposed model for the high-pressure phase Li₂[Al₂Si₃O₁₀]x6H₂O the Li⁺ cations have no contact with the framework O-atoms and are surrounded by "water-jacket" in the form of semi-octahedron (tetragonal pyramid) composed of five H₂O molecules. Such polyhedra, lining up along the channel axis, are joined through their edges and create a "water" column expanding the structure.

The behavior of K-exchanged gonnardite K_2,18Na_0,04Ca_0,02(H₂O)_2,2 [Al_2,26Si_2,74O₁₀] at compression in penetrating water-containing medium was studied by synchrotron powder diffraction in diamond anvil cell. In contrast to the initial gonnardite, which exhibits the transition to high-hydrated paranatrolite at elevated humidity, its K-exchanged form is not capable of over-hydration even at high pressure. Within the whole studied pressure range (up to 4.8 GPa) the sample experiences the compression. At 3.5-4 GPa the compression anomaly is observed, which is interpreted as a phase transition accompanied by the symmetry lowering from tetragonal to monoclinic. The high-pressure structure evolution of K-exchanged forms of gonnardite and natrolite is compared; the difference in their behavior is explained by distinct configuration of the framework water-cation subsystem.

The formation of the high-pressure hydrous phase Mg₃Si₄O₁₀(OH)₂xxH₂O (10 Å phase) through the reaction ‘talc+water’ at 450°C and 4 GPa was studied using diamond anvil cell. The powder diffraction measurements in situ , performed at the Siberian Center of Synchrotron and Terahertz Radiation (SSTRC), were applied to refine the lattice parameters, atomic coordinates and the occupancy of interlayer H₂O site in the structure of 10 Å phase at 450°C and 4 GPa. The lattice parameters are a = 5.234(1), b = 9.053(2), c = 10.87(1) Å, β = 99.2(1)^о, and V = 508.5(6) ų (space group C2/m). The results of Rietveld refinement show the best fit for the trioctahedral mica structure with split position Ow of the interlayer H₂O molecule. The half occupancy of the Ow site corresponds to one H₂O molecule per formula unit.

Nanocomposites based on PtPd-nanoparticles with chemical ordering like disordered solid solution on surface of multilayer graphene have been prepared through thermal shock of mechanically obtained mixture of double complex salt [Pd(NH₃)₄][PtCl₆] and different carbon materials - exfoliated graphite, graphite oxide and graphite fluoride. An effect of original carbon precursors on formation of PtPd bimetallic nanoparticles was studied using X-ray absorption spectroscopy (XAFS), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). It was shown that the distribution of bimetallic nanoparticles over the multilayer graphene surface as well as the particles size distribution is controlled by the graphene precursors. For all nanocomposites, the surface of the nanoparticles was found to be Pd-enriched. In case when the thermal exfoliated graphite and graphite oxide were used as the graphene precursors a thin graphitized layer covered the nanoparticles surface. Such a graphitized layer was not observed in the nanocomposite, which used the fluorinated graphite as the precursor.

Ge K-edge EXAFS (Extended X-Ray Absorption Fine Structure) spectra have been measured for multilayer semiconducting heterosystems containing interacted groups of quantum dots ("molecules from quantum dots") ordered in rings on different stages of their growth depending on topologic parameters and growth conditions. In accordance with our results obtained previously for the quantum dots of SiGe, for the molecules of quantum dots it was found that deformation at the interface leads to decrease in the interatomic distance of Ge-Ge by ~0.03 Å. Effect of heterosystem topology and temperature at different stages of their growth on interlayer diffusion was investigated. It was found that at the first growth stage (growth of "seeded islands" serving as a basis for obtaining the molecules) at 700°C a concentration of Ge atoms in the system is ~38%. With further growth of the vertically-matched quantum dots groups the concentration of Ge increases up to ~43-47% depending on the growth conditions. Comparable analysis of different modes of EXAFS measurements was performed to determine precisely structural parameters of heterosystem SiGe with different thickness grown on Si(100) surface.

In the work the results of structural studies of nanocomposite systems based on ZnS:Cu (5 at.% and 10 at.%) deposited by explosive evaporation on porous anodic aluminum oxide matrices fulfilled by EXAFS and X-ray phase analysis techniques have been presented. The composites under study are promising for applications in electroluminescent light sources. The results of the studies of emission intensity of light sources depending on frequency and amplitude of exciting field have also been presented.

The microwave synthesis of quantum dots based on CdS has been performed, the temperature ( T 180°C and 150°C) and synthesis duration (10 min and 5 min) have been varied. The analysis of the peak broadening in X-ray diffraction has shown that the average particle size in the synthesized samples is 10.02 nm for the CdS _{T = 180°C} sample and 5.22 nm for the CdS _{T = 150°C} sample. For both synthesis temperatures particles of sphalerite phase are formed but the sample CdS _{T = 180°C} contained some impurity of wurtzite phase too. Cd K -XANES spectra in the standard samples and quantum dots have been recorded using a Rigaku R-XAS X-ray absorption laboratory spectrometer. The theoretical analysis of the Cd K -XANES spectra of bulk samples of CdS and CdS nanoparticles has been performed. It has been shown that the theoretical difference spectra between bulk CdS and CdS with decreased lattice parameters demonstrate the same tendency as the experimental difference spectra between bulk CdS and the quantum dot samples under study. It has been shown that the theoretical Cd K -edge HERFD-XANES spectrum in CdS demonstrates considerably more detailed structure pointed to the need of the analysis of experimental Cd K -edge HERFD-XANES spectra to pick out more precise information on local atomic structure parameters of small semiconducting quantum dots.

Colloidal quantum dots of the CdSe family have been studied by X-ray absorption near edge structure (XANES) spectroscopy and computer modelling. Cd K -edge XANES spectra in colloidal quantum dots based on varisized CdSe nanoparticles have been recorded. Atomic structure of CdSe particles and also CdSe particles doped by transition metal atoms Mn and Co has been modelled based on the density functional theory. The embedding of the doping atoms is shown to result in considerable changes in the local atomic structure of CdSe particles. XANES spectra have been calculated above the Cd K -edge in CdSe particles, above the Mn K -edge in CdSe:Mn particles, above the Co K -edge in CdSe:Co particles. The sensitivity of XANES spectroscopy to small changes in structural parameters of the nanoparticles of CdSe family has been demonstrated that furnishes an opportunity to apply it for the verification of atomic structure parameters around positions of cadmium and doping atoms of transition metals in quantum dots based on CdSe.