Sodium formate is quite popular products in industries. Currently, there is no independent production NаНСОО, because it is synthesized in the production of pentaerythritol and an additive product of this technology. For the production of the required quality sodium formate it is necessary treatment of the product. It is known that the crystallization processes are widely used in the technology of reactive substances qualifying, and the first stage of polythermal crystallization largely has a significant impact on the quality of the crystalline product. In the article the influence of hydrodynamics, cooling rate, the saturation temperature and concentration of pentaerythritol on supersaturated sodium formate solutions to overcooling was shown. The mathematical equations that valid describe the revealed features of the process have been received. The dependences should be considered in treatment technology of sodium formate crystallization method.

Keywords: sodium formate, metastable zone width, polythermal crystallization, oversaturation, impurities pentaerythritol

In this work, the nanoparticles were investigated biogenic metals iron, fine and coarse copper nanoparticles, the nanoparticles of zinc test samples showed pronounced antitumor activity in the body tumor-bearing rats. Nanoparticles were introduced into the body of rats as a solution in sodium chloride .On laboratory X-ray absorption spectrometer R-XAS Looper were measured X-ray absorption spectra (XANES) of reference samples of iron, copper, zinc foil, iron oxide, copper, zinc and investigated nanoparticles. Based on the data, it was concluded that their structure, charge state and redox pure powders and sodium chloride.

Keywords: magnetic fluid, magnetite, nanoparticles, Fe3O4, oxidation state, density, antitumor activity

In this article we consider the use of quasi-homogeneous approximation to describe the properties of disperse systems. We used a statistical method of polymer based on the consideration of all possible structures averaged macromolecules of the same weight. The equations to assess many additive parameters of macromolecules containing their systems. Statistical polymer method allows modeling branched, cross-linked macromolecules and containing their system in a state of equilibrium or non-equilibrium state. Fractal consideration of random polymer allows you to s imulate different types of random fractals and other objects studied by the methods of fractal theory. A method of statistical polymer is not only applicable to the polymers but also to composites gels associates in other polar liquids and aggregate systems. In this paper we described the state of colloidal solutions of silica from the viewpoint of statistical physics. This approach is based on the idea consists in the fact that a colloidal solution of silicon dioxide - silica sol consists of a very large number of interacting particles in a continuous motion. It is dedicated to the study of an idealized system of colliding, but not interacting particles sol. Analyzed the behavior of silica sol, in terms of Maxwell-Boltzmann distribution was calculated and the mean free path of the colloidal particles. Based on these data, it was calculated the number of particles that can overcome the potential barrier in a collision. For modeling the kinetics of the sol-gel transition, we have discussed various approaches.

Keywords: quasi-homogeneous approximation, disperse systems, statistical polymer method, the formation of cross-links, fractal method, sol, silica sol, sol-gel transition, the mean free path

The paper discussed the mechanism of formation of polycrystalline hexagonal barium ferrite. The influence of alloying elements on the location of Fe3 hexagonal block R, on the border of hexagonal and spinel blocks (RS). It is shown that the presence of weakly diamagnetic ions or dopants in these positions provides specific properties of hexagonal ferrites and their practical use.

Keywords: hexaferrite barium, dopant, magnetic properties, the mechanism of formation, anisotropy, polycrystalline, magnetization, Mossbauer spectroscopy, the coercive force, Curie temperature

Research of possibility of management of morphological parameters of arrays nanoparticles Au (form, the size, density of superficial distribution) of the thin films of ZnO received on a surface by method of the pulse laser deposition (PLD) with subsequent annealing in the inert atmosphere was conducted. It was experimentally established that increase of the average size of Au nanoparticles leads to the plasmon peak broadening and its shifting to the red region. Nanoparticles with diameters 17, 25, 31, 37 and 40 nm have plasmon absorption maximums at wavelengths 570, 590, 605, 610 and 620 nm, respectively. With the increase of the average nanoparticle size nm to a certain value rise of maximum in absorbtion spectra at wavelengths 570, 590, 605 and 610 followed by its decrease at 620 nm is observed. The highest value of the intensity at/in the absorption maximum corresponds to the average diameter of the nanoparticles of 37 nm. Optimal conditions for synthesis of isolated arrays of Au nanoparticles on the surface of ZnO thin films with high maximum of plasmon absorption were experimentally found. Obtained results can be used to increase the sensitivity of the photodetectors and solar cells based on zinc oxide or chemosensors based on Raman amplification effect near the gold nanoparticles.

Keywords: nanoparticles of Au, arrays of isolated nanoparticles, plasmon resonance, a photodetector, photosensitivity, ZnO film

The technique of determination of local atomic structure in the vicinity of absorbing atom in the case of the presence of strong correlation between fitting parameters is proposed. This technique is applied to three test signals simulating the Pt L3-edge EXAFS spectra of Pt/Ag bimetallic nanoparticles. The test results demonstrates the improvements in precision of determined parameters comparing with common technique.

Keywords: Extented X-ray Absorbtion Fine Structure, EXAFS, multiparameter curve fitting, correlation between fitting parameters, bimetallic nanoparticles, local atomic structures, CUDA

Composites La0,67Sr0,33MnO3 (SiO2, Sb2O3) with different weight ratios have been synthesized. Their magnetoresistive and dielectric properties have been investigated. It has been established that in the frequency range from 10 to 106 Hz for SiO2 concentration of 10% the colossal magnitudes of the dielectric constant ( ~ 4 • 104) take place. The values of the negative isotropic magnetoresistance for samples with silica at room temperature is 8.6%, with abarriers of antimony oxide reaches 12%, which makes it possible to use such materials in spintronics.

Keywords: Magnetoresistance, colossal dielectric permittivity, glass composites, X-ray diffraction, spin polarization, barrier layers, tunneling, microstructure, dielectric spectrum, Maxwell-Wagner effect.

Recent advances in chemistry and technology of nonisocyanate polyurethane (NIPU) materials based on cyclic carbonate oligomers are reviewed in this paper. Reaction of the cyclic carbonate and amino groups results in β-hydroxyurethane fragments with specific properties. Primary attention is given to the hybrid materials that contain epoxy and acrylic compounds, especially materials based on renewable raw materials. Hybrid organic composites comprising of silanes are also considered. An overview of the recent publications in this field is provided with a more detailed description of achievements by the authors and their corporate employees. The use of NIPU materials as coatings, adhesives, and foams is described.

Keywords: nonisocyanate polyurethanes, cyclic carbonate oligomers, hybrid polymers

The paper presents the results obtained after study of the effects produced by differently oriented electric fields upon the electronic structure and spin-polarized transport in 1D graphene channel placed on wide bandgap semiconductor of the А3В5 type. Ab initio calculations of total energy and band structure have been performed within the framework of the density functional theory using Grimme's DFT(PBE)-D2 scheme. It has been demonstrated that carrier mobility in a 1D semiconductor channel of the ZGNR/А3В5(0001) type may reach the values of (1.7-30.5).10^4 cm^2/Vs and can be controlled using electric field.

Keywords: graphene nanoribbons, nitride aluminum, ab initio, semiconductor, electric field, band structure, density functional theory, transport properties, electronic properties.

In this paper the environmental effects on the vibrational properties of individual carbon nanotubes were studied by means of Raman spectroscopy. The individual nanotubes were first synthesized by catalytic chemical vapour depositon method. Then their geometric structure was determined by electron diffraction and high-resolution electron microscopy. The intrinsic experimental relationship between RBM frequency and the tube diameter was obtained and certain deviations from the expected 228/d relationship were found. The effect of the substrate was identified as the most probable explanation for these experimental observations. In order to quantify the origins of deviations, we propose a comparison between our experimental data and calculations performed in the framework of elasticity theory.

Keywords: individual carbon nanotubes, Raman spectroscopy, radial breathing modes, environmental effects

In this paper a method for the atomic structure analysis of single-walled and multi-walled carbon nanotubes based on the combination of Raman spectroscopy and electron diffraction is presented. We discuss the main criteria of this method and give an example of index-assignment of individual double-walled carbon nanotube. We argue that the combination of several techniques gives the most accurate and unambigous structure identification.

Keywords: individual carbon nanotubes, Raman spectroscopy, electron diffraction, electron microscopy

Symmetry of single-walled carbon nanotubes is analyzed using the parent phase approach. Transfer of the planar hexagonal order of graphene sheet onto surfaces of chiral and achiral nanotubes is divided into two steps. At the first step the rotational symmetry of graphene is reduced. In addition, the reflection symmetry is vanished for chiral nanotubes. At the second step the resulting subgroup symmetry is mapped in homomorphical way onto the symmetry group of the single-walled nanotube.

Keywords: crystalline symmetry, group theory, parent phase, single-walled carbon nanotubes, graphene

A study of X-ray absorption spectra depending solution of copper (II) and cobalt from the time of preparation of these solutions (immediately prior to the measurement and aged for six months), as well as the dependence of the spectra on the acidity of the solution (different levels of pH 5.7 and 1, which is achieved by addition of hydrochloric acid). Processing of the experimental spectra were in the software package Athena. The study established according to the experimental X-ray absorption spectra of the solution of copper (II) and cobalt chloride on the test conditions.

Keywords: X-ray absorption spectroscopy, soft X-rays, copper chloride, copper (II), cobalt chloride aqueous solution, X-ray absorption spectrometer Rigaku R-XAS, a cell with kapton window

High-temperature (295 - 1000 K) Raman studies of Nd-doped bismuth ferrite epitaxial heterostructures were performed. The bands 620 cм-1 and 1260 cm-1 were observed in the high-frequency range above the first-order phonons. The band 620 cм-1 corresponds to the maximum density of states of magnon branch at the Brillouin zone boundary. The intense second-order band at about 1260 cm-1 corresponds to the density of states of two-magnon excitations. The intensity of two-magnon scattering decreases with increasing temperature, and above the Neel temperature paramagnon scattering typical for antiferromagnetics was observed.

Keywords: Raman spectroscopy, multiferroic, bismuth ferrite, heterostructure

The presence of colossal dielectric constant in the low frequency region is observed in the strontium ferrite with hexagonal structure. This result can be explained in the framework of the "grain-layer" and the polarization of Maxwell - Wagner in the ceramic medium. The effect of negative capacitance in ceramic strontium hexaferrite at a frequency of less than 2.10 Hz has been detected.

Keywords: hexaferrite strontium, ferromagnetic, insulator, semiconductor, colossal dielectric constant, negative capacitance, high-temperature annealing, X-ray structural analysis, full-profile analysis, electron microscopy.

Band structure calculations were performed for quasi-2D MeO systems using the pseudopotential method within density functional theory. The calculations were carried out within the plane waves methodology using pseudopotentials. Density of electron states was calculated within the approxination of collinear magnetism. We examined the electron structure and estimated the electronic and magnetic properties of FM-ordered quasi-2D MeO systems (Me = Mn, Fe, Co, Ni). It has been demonstrated that the MnO - FeO - CoO - NiO row exhibits a shift in 3d spin down states of the metal relatively to the Fermi level towards the low-energy region. The above affects magnetization in 2D systems of oxides of 3d transition metals. The character of electron density distribution in quasi-2D MeO systems (Me = Mn, Fe, Co, Ni) indicates ionic bond type between the atoms in Me systems. The tendency towards increase of the band gap in the FeO→ CoO→ NiO row has been established. The obtained estimates of the local magnetic moment of a 3d transition metal atom in crystals of examined oxides correlate with experimental data. In conformity with existing views in physics, we have revealed the effect of spontaneous spin polarization of Me 3d and 2p bands of oxygen atoms in quasi-2D MeO systems (Me = Mn, Fe, Co, Ni), which in our opinion plays the main role in generation of magnetic moments in the atoms of 3d transition metal and oxygen.

Keywords: Density functional theory, pseudopotential mathod, ferromagnetism, electronic band structure, transition metal oxides

The atomic structure of bimetallic nanoparticles of Pt-Ag composition, which are the part of metal-carbon electro-catalysts PtAg/C, is studied by means of EXAFS spectroscopy using the suggested technique. These materials have been prepared by methods of consistent and simultaneous deposition of Ag and Pt atoms from aqueous ethylene glycol solutions of their salts with subsequent acid treatment. The values ​​of the structural parameters of the near environment of platinum atoms are determined. The nature of the distribution of components in nanoparticles is established. Cluster models of nanoparticles are constructed. The fraction of Pt atoms in the working shell and its dependance on preparation methods in each case are determined.

Keywords: Metal-carbon electrocatalysts, bimetallic nanoparticles, Catalysis, Platinum, X-ray absorption spectroscopy, atomic structure

By self-propagating high-temperature synthesis (SHTS) prepared fine powder оf La2-xSrxNiO4 composition , which is used to obtain dense ceramics exhibiting the properties of n-type semiconductor. Prolonged annealing of the samples resulted in a decrease of the conductivity on the order of 3-4, and the changing nature of the dielectric spectrum: dielectric constant ε' has a stable value of 4·104 Hz in the range of 0,4 − 1·105 Hz .

Keywords: dielectric constant, phase separation, nikelate of strontium lanthanum, self-extending high-temperature synthesis

This paper presented the study of the mechanochemical activation powder mix in dry and liquid grinding media, accompanied by agglomeration of the particles. It Is shown that when agglomerate particles having a bimodal size distribution is forming during the treatment in a dry grinding media and partially (2 wt % ) decaying at grinding by pestle in mortar. The transition to liquid grinding media is leading to a unimodal size distribution and increasing dispersion of the agglomerated particles, characterized by secondary agglomerating when using the alcohol and destruction when using activation in saturated aqueous solution of boric acid. Inherited effect mechanical activation parameters on the compaction process during cold compaction and hot stamping has been determined. Application treated in a high energy mill in an grinding media saturated aqueous H3BO3 Al-Si powder mix results in the formation of moldings with low cold-pressing relative density (0.735) and the activation of the hot stamping compaction (|εh| = 0,592) providing production of hot-deformed powder material with increased mechanical properties.

Keywords: mechanochemical activation, hot-deformed powder material, aluminum, silicon, dispersion, agglomeration

The composite cathode material of the core@shell type with the LiMn2O4@LiCoO2 formula of has been successfully synthesized using the solid-state reactions in several stages. Its structure has been studied by means of X-ray diffraction, scanning and transmission electron microscopy and vibrational infrared spectroscopy. Electrochemical investigation in two-electrode cell has been showed improvement of characteristics of the synthesized cathode material than the constituent components. The specific power of LiMn2O4@LiCoO2 is 650 mWh/g, against 450 and 500 mWh/g for LiCoO2 and LiMn2O4, respectively.

Keywords: lithium-ion batteries, cathode materials, Delafosse, X-ray structural analysis, electron microscopy, electrochemical properties

The solid solution of  LiMn1/3Cr1/3Fe1/3O2 with the structure of α-NaFeO2  isostructural with the widely used LiCoO2  has been synthesized and investigated as a cathode material. Rated voltage of LiMn1/3Cr1/3Fe1/3O2  relative to the lithium is 4 V.  The possibility of charging − discharging the material to a specific capacity of 220-250 mAh/g at currents of C/15-C/50 without phase transformations has been experimentally demonstrated. 

Keywords: lithium-ion batteries, cathode materials, Delafosse, solid solution, X-ray structural analysis, electrochemical properties

In this paper we study of the local atomic and electronic structure of nanostructured condensed material for rechargeable current sources on the basis of 15mas.%V2O5/Fe/LiF nanocomposite within charge-discharge cycle. Principle component analysis (PCA) of the series of Fe K-edge spectra collected during 1 st charge showing the concentrations of the components Fe, FeF2 and V[FeV]O4. We found the changes in the V oxidation state from the analysis of the experimental Fe K- and V K- XANES spectra. Total and partial density of states of components are presented.

Keywords: nanostructured materials for rechargeable current sources, dynamics of local atomic and electronic structures, XANES, DFT

In this paper a systematic study of individual single-walled and multi-walled carbon nanotubes was performed by Raman spectroscopy and high-resolution electron microscopy. We have presented the geometrical and electronic structure analysis on the examples of two tubes: individual single-walled and double-walled nanotubes. The role of different environmental effects and their influence on the final structure assignment are discussed. Moreover, we have shown that the Raman spectroscopy gives reliable estimations of the nanotube diameters and the conductivity. Given a non-destructible character of Raman spectroscopy, we may conclude that it is one of the most efficient methods for structure analysis of carbon nanotubes.

Keywords: Carbon nanotubes, Raman spectroscopy, electron microscopy

In this work we have investigated the structure of individual single-walled and multi-walled carbon nanotubes by high-resolution electron microscopy and electron diffraction. To grow carbon nanotubes we used a catalytic chemical vapor deposition method. It was shown, that this synthesis protocol gave in general single-walled and double-walled carbon nanotubes with a high level of crystallinity. The diameters of the nanotubes were in the range 1.5 - 7 nm. We also observed that there was a certain level of amorphous carbon deposited on the nanotube surface during the growth. In this work we also present the structure analysis of the double-walled carbon nanotube by means of electron diffraction. We show that the structural date derived from electron microscopy and electron diffraction agree within the experimental error.

Keywords: Carbon nanotubes, electron diffraction, electron microscopy

The possibility of channeling X-ray fluorescence inside the hollow microvascular at the energy of the exciting radiation in the vicinity SiL2, 3 - absorption edge has been researched. Theoretically obtained the angular distribution of the field passing through the microchannels. The calculation model of inhomogeneous waveguide layer with the generation of X-ray fluorescence inside the walls of the microchannels shows the possibility of escape of radiation at large angles.

Keywords: channeling of X-ray fluorescence, microchannel plates, focusing of X-ray radiation