This paper is a brief summary of the results of long-term experimental studies of C60Hx hydrofullerites with a hydrogen content of up to x ~ 60 or more, obtained by loading C60 fullerites with hydrogen at pressures up to 9 GPa and temperatures up to 500°C. Basically, this is an overview of already published data. Some results for hydrofullerites with compositions of x ~ 60 and x ~ 90 are presented for the first time.

Wood of forest beech (Fagus sylvatica L.) has high physical and mechanical properties and is widely used in various industries. In this paper, it is shown that, when exposed to elevated temperatures, changes in the chemical composition of forest beech wood, disordering of bonds in the system of lignin and holocellulose, transformation of lignin, and decomposition of holocellulose caused mainly by the decomposition of part of hemicelluloses occur.

Исследовано строение и физические свойства аморфных пленок SiOx, полученных химическим травлением аморфного ленточного сплава на основе железа. Нейтронная дифракция, а также атомно-силовая и электронная микроскопия показывают, что полученные визуально прозрачные пленки имеют аморфную структуру схожую с морфологией опалов и обладают диэлектрическими свойствами. Методами дифференциально-сканирующей калориметрии, рамановской и ИК-спектроскопии была проведена оценка степени упорядоченности в структуре образцов до и после их термической обработки. Установлено, что отжиг пленок в воздушной среде, при температуре 1273 K, приводит к изменению их химического состава в сторону соединения SiO2, с включениями фазы кристобалита. The present paper contains investigations of the structure and physical properties of amorphous SiOx fi lms synthesized by the chemical etching of the amorphous Fe-based alloy bands. Neutron diff raction, atomic-force microscopy and electronic microscopy prove that the synthesized visibly transparent fi lms have the amorphous structure, similar to the morphology of the annealed films and possessing dielectric properties. By using the methods of diff erential scanning calorimetry, Raman spectroscopy and infrared spectroscopy there was performed the assessment of the order in the structure of the samples prior to and after their thermal treatment. It was established that the annealing of the fi lms in the air medium at the temperature of 1273° K results in the changing of the fi lms’ chemical composition towards the SiOx compound, with inclusions of the cristobalite phase.

AbstractThe structure and the physical properties of amorphous SiO_ x films prepared by chemical etching of an iron-based amorphous ribbon alloy have been studied. The neutron diffraction and also the atomicforce and electron microscopy show that the prepared visually transparent films have amorphous structure, exhibit dielectric properties, and their morphology is similar to that of opals. The samples have been studied by differential scanning calorimetry, Raman and IR spectroscopy before and after their heat treatment. It is found that annealing of the films in air at a temperature of 1273 K leads to a change in their chemical compositions: an amorphous SiO_2 compound with inclusions of SiO_2 nanocrystals (crystobalite) forms.

contact with the ampoule walls and absence of plastic deformation of the crystal under its own weight. For improvement of the fullerite C60 crystal growth technology before the scheduled space experiments on the ISS the growing of the high purity grade fullerite C60 crystals with the sufficiently high structural perfection were carried out on the Earth from the C60 vapor in sealed quartz ampoules (pre-evacuated to the pressure of 10−3 Pa) at temperatures in the evaporation zone ranging from 560 – 610 ◦C with a temperature gradient between the evaporation and deposition zones of 3 – 10 K/cm within 72 h. The grown single crystals had a size of ∼ 5× 5× 5 mm and habitus corresponding to the fcc lattice. IR spectroscopy shows the high purity fullerite C60.

The structure and the physical properties of amorphous SiO x films prepared by chemical etching of an iron-based amorphous ribbon alloy have been studied. The neutron diffraction and also the atomicforce and electron microscopy show that the prepared visually transparent films have amorphous structure, exhibit dielectric properties, and their morphology is similar to that of opals. The samples have been studied by differential scanning calorimetry, Raman and IR spectroscopy before and after their heat treatment. It is found that annealing of the films in air at a temperature of 1273 K leads to a change in their chemical compositions: an amorphous SiO 2 compound with inclusions of SiO 2 nanocrystals (crystobalite) forms.

A new hydrocarbon - hydrographite - with the composition close to CH is shown to form from graphite and gaseous hydrogen at pressures above 2 GPa and temperatures from 450 to 700 degrees C. Hydrographite is a black solid thermally stable under ambient conditions. If heated in vacuum, it decomposes into graphite and molecular hydrogen at temperatures from 500 to 650 degrees C. Powder X-ray diffraction characterizes hydrographite as a multilayer "graphane II" phase predicted by ab initio calculations [Wen X-D et al. PNAS 2011; 108: 6833] and consisting of graphane sheets in the chair conformation stacked along the hexagonal c axis in the - ABAB - sequence. The crystal structure of the synthesized phase belongs to the P6(3)mc space group. The unit cell parameters are a = 2.53(1) angstrom c = 9.54(1) angstrom and therefore exceed the corresponding parameters of graphite by 2.4(2)% and 42.0(3)%. Stretching vibrations of C-H groups on the surface of the hydrographite particles are examined by infrared spectroscopy. (C) 2015 Published by Elsevier Ltd.

Significant changes in infrared absorption spectra of polystyrene upon the addition of cesium sulfate nanoparticles to it are observed, which is due to two variants of attachment of organic molecules to nanoparticles (through hydrogen and pi bonds). The relation between the bonds changes significantly during deformation of polystyrene/cesium sulfate composite owing to differences in the mechanical strength thereof. In its turn, the differences in atomic and electronic bond structures result in a significant differentiation of their influence on light emission processes, making it possible to control the scintillation characteristics of polystyrene/nanoparticle composites via regulating their composition and morphology.

We have investigated nanoparticles (NPs) formation in Si by Zn-64(+) ion implantation at substrate temperature of 350 degrees C. Hot implantation was chosen to avoid amorphization of Si near-surface layer. In as-implanted samples the Zn crystal NPs were created. Then the samples were subsequently subjected to isochronous annealing in oxygen at elevated temperatures. The depth profile of implanted Zn was analyzed by Rutherford backscattering spectroscopy. The dependence of photo-luminescence spectra on annealing temperatures was observed. In these spectra the peak at 370 nm attributable to ZnO phase and wide peak at 430 nm due to defects were revealed. The visualization and identification of NPs were obtained by transmission electron microscopy and transmission electron diffraction of cross-section samples. From these study it follows, that after annealing at temperature of 700 degrees C and higher the NPs with structure of Zn(core)/ZnO center dot Zn2SiO4(shell) were formed. Auger electron spectroscopy investigation followed the phase content in depth profile was varied from ZnO center dot Zn2SiO4 at a substrate surface to metal Zn in a substrate body.[GRAPHICS]. (C) 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

The transmission and Raman spectra of C 60 H 42 samples synthesized at a high hydrogen pressure and stored under different conditions have been measured. It has been found that, upon interaction of the compound with air, a part of C 60 -H chemical bonds are replaced by C 60 -O-H bonds. It has been experimentally shown that the observed changes in the vibrational and electronic properties of C 60 H 42 are caused by the interaction of the compound with atmospheric oxygen and water vapor. The rate of oxidation of the studied samples is significantly less than the value previously published for the oxidation of the C 60 H 36 compound synthesized by the reduction of fullerene C 60 dissolved in different solvents with the use of Zn/HCl. This is explained by the fact that particles of the product of the hydrogenation at a high hydrogen pressure are polycrystals with relatively large sizes, unlike the fullerene hydrides synthesized by the reduction of C 60 with Zn/HCl.

The distribution profiles of the dopant in the surface layer of a SiO2/Si structure implanted with Zn and O ions are studied via Rutherford backscattering spectroscopy for He2+ ions using the channeling technique. The redistribution of implanted impurities in the Si surface layer during the formation process of zinc oxide (ZnO) nanoparticles is analyzed. The effect of the annealing temperature on the formation process and growth of ZnO nanoparticles is studied. The sample-surface morphology is examined via atomic force microscopy. The optical absorption and photoluminescence of the implanted layers are studied.

A solid-phase composite material based on multi-walled carbon nanotubes and an ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate) has been synthesized. It has been found using infrared spectroscopy that vibrational modes of the ionic liquid are shifted by 4–12 cm −1 toward lower energies with respect to those observed in the initial fluid due to the interaction of ionic liquid molecules with the nanotubes. Electron microscopy has revealed that, in the composite, the ionic liquid is present on the surface of nanotubes and partially inside them. It has been shown that the degree of extraction of lanthanides from aqueous solutions with the use of the synthesized composite increases with increasing content of the ionic liquid in it.

The investigation of ZnO NPs formation in SiO2/Si structure by Zn+ ion implantation with furnace annealing is presented. After implantation the samples were subsequently isochronally subjected to annealing during 1 h in nitrogen at 400 degrees C, and then in oxygen at 600 and 800 degrees C. The radiation defects and Zn implant profiles were investigated by Rutherford backscattering spectroscopy. Optical absorption spectra from reflection experiment data of the test samples were studied at room temperature in a spectral range 250-600 nm. Photoluminescence was spent using He-Cd laser with wavelength 325 nm in a spectral range of 240-800 nm. After implantation in SiO2 film were created metal Zn NPs. After annealing at 400 degrees C Zn there occurred increasing of Zn NP size. During annealing in temperature range of 600-800 degrees C there occurred transformation from Zn metal NPs to its oxide form ZnO.GRAPHICS(C) 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Magnetic materials are usually divided into two classes: those with localised magnetic moments and those with itinerant charge carriers. We present a comprehensive experimental (spectroscopic ellipsomerty) and theoretical study to demonstrate that these two types of magnetism do not only coexist but complement each other in the Kondo-lattice metal, Tb2PdSi3. In this material the itinerant charge carriers interact with large localised magnetic moments of Tb(4f) states, forming complex magnetic lattices at low temperatures, which we associate with self-organisation of magnetic clusters. The formation of magnetic clusters results in low-energy optical spectral weight shifts, which correspond to opening of the pseudogap in the conduction band of the itinerant charge carriers and development of the low- and high-spin intersite electronic transitions. This phenomenon, driven by self-trapping of electrons by magnetic fluctuations, could be common in correlated metals, including besides Kondo-lattice metals, Fe-based and cuprate superconductors.

Fullerit C 60 single crystals were grown by sublimation on Earth and under microgravity during the FOTON-M3 mission using the same growth parameters and the same multizoned electrovacuum POLIZON-M furnace. IR spectroscopy and X-ray measurements revealed the considerably better crystal structure of the crystals grown under microgravity.

It has been found that treatment of europium molybdate single crystals under high uniform pressure leads to radical changes of the IR reflectance spectra of the samples. Instead of a series of narrow lines, which are characteristic of the spectrum of the initial crystal, the spectrum of the sample subjected to pressure treatment exhibits broad bands. As follows from the results of X-ray diffraction measurements, this transformation of the IR spectra is associated with the fact that, after pressure treatment, the sample represents an amorphous matrix with inclusions of nanocrystals of the high-pressure phase. In the IR spectra, the high-pressure phase manifests itself in the form of a new line at approximately 600 cm −1 . After annealing of the sample with an increase of the temperature from 100 to 400°C, the high-pressure phase disappears. A further increase of the annealing temperature to 550°C leads to the recovery of the crystal structure of the initial β′ phase of europium molybdate and to the appearance of lines corresponding to the α phase.

Highly porous periodic structures consisting of a three-dimensional replica of pores in the initial opal lattice have been synthesized by high-temperature thermochemical treatment of opal matrices filled with carbon compounds, followed by dissolution of silicon dioxide. It has been shown that the main phases of the composite are carbon and silicon carbide. Based on the X-ray diffraction, Raman, and IR spectroscopy data, it has been assumed that the composite contains fragments of hexagonal diamond. The photoluminescence and optical reflection spectra of the composites have been measured.

The conditions for synthesizing an opal-zirconia-carbon nanocomposite in the form of monolithic (without pores) transparent silica with an ordered distribution of nanocrystals throughout the sample have been determined. Zirconia nanocrystals form a three-dimensional periodic lattice of nanoclusters with sizes ranging from several nanometers to several tens of nanometers. This nanocomposite exhibits properties typical of photonic crystals. The samples have been studied using electron microscopy, X-ray diffraction, photoluminescence, and Raman scattering. The structural state and spatial arrangement of zirconia nanocrystals and carbon clusters in the nanocomposite have been elucidated. Optical transmission and optical reflection photoluminescence spectra of the nanocomposites have been measured.