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Tube bundles are an integral part of the two-phase heat exchangers and are employed in numerous commercial applications. Present research compares two kinds of horizontal staggered tube bundles under upward crossflow boiling to see how tube rows affect the heat transfer coefficient (HTC). The experimental setup developed houses the tube bundle for temperature measurements and facilities the recording of high-speed images at different operating conditions. The investigation is carried out for heat fluxes of 10–75 kW/m2, mass fluxes of 20–100 kg/m2s, and P/D ratios of 1.25, 1.6, and 1.95, with distilled water as the working fluid. It is observed that both tube bundles show an increase in overall HTC with an increase in heat flux. However, the 5 × 3 tube bundle resulted in a greater heat transfer rate as compared to the 2 × 3 tube bundle due to the bundle effect. Further, both tube bundles have a diminishing trend of HTC with a rise in mass flux. The rate of rising in HTC was found to decrease with an increase in the number of tube rows in the tube bundle and with an increase in the P/D ratio. Therefore, interestingly it is observed that the increase in bundle average HTC of 5 × 3 tube bundle is not twice that of 2 × 3 tube bundle rather it is quite lesser which further deteriorates with an increase in P/D ratio. The row-wise and bundle average HTC obtained is also predicted with a dimensionless correlation within an error of ± 15%.

Along with a brief overview of literature data on energy storage technologies utilising hydrogen and metal hydrides, this article presents results of the related R&D activities carried out by the authors. The focus is put on proper selection of metal hydride materials on the basis of AB5- and AB2-type intermetallic compounds for hydrogen storage and compression applications, based on the analysis of PCT properties of the materials in systems with H2 gas. The article also presents features of integrated energy storage systems utilising metal hydride hydrogen storage and compression, as well as their metal hydride based components developed at IPCP and HySA Systems.

The structure, hydrogen storage and electrochemical properties of annealed low-Co AB5-type intermetallic compounds have been investigated. La-alloy, Nd-alloy and Cr-alloy are used to represent La0.8Ce0.2Ni4Co0.4Mn0.3Al0.3, La0.6Ce0.2Nd0.2Ni4Co0.4Mn0.3Al0.3 and La0.6Ce0.2Nd0.2Ni3.8Co0.4Mn0.3Al0.3Cr0.2, respectively. The XRD results indicated that annealed samples are all single-phase alloys with CaCu5 type structure. The maximum of both hydrogen content and discharge capacity is obtained for La-alloy 1.23 wt%H2 and 321.1 mA h/g, respectively. All the investigated alloys are quiet stable with ΔH of hydrogen desorption about 36–38 kJ/mol H2. Cycle life of alloy electrode has been improved by partial substitution of La for Nd and Ni for Cr. The highest capacity retention of 92.2% after 100 charge/discharge cycles at 1C has been observed for Nd-alloy. The hydrogen diffusion coefficient measured by PITT is higher at the start of charging process and dramatically reduces by 2–3 order of magnitude with saturation of β-hydride. The highest value 6.9 × 10−13 cm2/s is observed for La alloy at 100% SOC. Partial substitution La for Nd and Cr for Ni in low-Co AB5 metal hydride alloys slightly reduces maximum discharge capacity, HRD performance and hydrogen diffusion kinetics. Low-Co alloys show good overall electrochemical properties compared to high-Co alloys and might be perspective materials for various electrochemical applications.

Introduction of finely disperse mineral additives of natural and man-made origin to Portland cement in order to improve the indicators of its physical-mechanical properties and partially replace clinker is one of the urgent directions for solving the resource and energy saving problems, as well as environmental protection problems in the production and application of building materials. The expansion of the raw material base of mineral additives can be achieved by using calcined polymineral clays, which are common in many regions of the Russian Federation, including the Republic of Mordovia. The article presents the results of research on the effects of calcination temperature and time of thermally activated polymineral clays of the Republic of Mordovia on their physical-chemical efficiency in cement systems. According to the study results of dehydration processes of clay minerals using the synchronous thermal analysis, it is established that the optimum calcination temperature for clays of Nikitsky and Staroshaigovsky deposits located in the area of 500–800 °C. This temperature range corresponds to the processes of the initial crystal structure restructuring of clay minerals of the kaolinite and illite groups, associated with their dehydroxylation, which contributes to the transition of these phases to the active form. The optimization of calcination parameters of polymineral clays based on the study results of influence of their additives on the mixed cement binder activity confirmed the thermal analysis data. It was found that the production of mineral additives with the highest values of the activity index is facilitated by 2-hour heat treatment of clays at 700 °C. At the specified calcination parameters, the replacement of 10% of Portland cement with the additive of thermally activated Nikitsky clay allows achieving the mixed binder activity that exceeds by 3 % the same indicator of mixed binder based on Portland cement and high-quality metakaolin.

By optical methods (Raman spectroscopy, infrared spectroscopy, X-ray photoelectron spectroscopy) and electron-microscopy techniques, it was found that the atomic structure of germanium monoxide films of stoichiometric composition corresponds to the random bonding model and does not contain germanium nanoclusters. This structure is metastable and transforms into a random mixture structure at a temperature of 260°C and higher. The metastability of solid GeO can be caused by internal strains in the atomic network.

The paper presents results of an experimental study of the effect of pin microstructures on the wetting front propagation and its structure under adiabatic conditions and on strongly pre-heated surfaces, as well as the heat transfer and critical heat fluxes under steady-state heat release with liquid nitrogen film flowing. The surface structuring was created by the deformational cutting method (DCM). Comparison with data obtained on a smooth heater is presented. It is shown that the microstructures created by the DCM may have a significant effect on the nature of the temperature curves, reducing the total time of plate cooling at rewetting up to 2 times, and significantly change the structure and dynamics of the wetting front under adiabatic conditions. At the same time, such microstructuring with preset parameters of microfinning has weak influence on the heat transfer under steady-state heat release. High-speed video data of the processes are presented.

The processes of crystallization of amorphous germanium films of various thicknesses and multilayer germanium/silicon nanostructures under isothermal annealing (T = 440°C) were studied. Samples were grown on glass substrates using the method of plasma-chemical deposition. The phase composition of the structures was determined from the analysis of Raman spectra. It was found that 200 nm thick germanium film almost completely crystallizes after two hours of annealing, while crystalline nuclei with a volume fraction of less than 1% only appear in a 6 mm thick germanium film. Four-hour annealing of a thin film leads to a noticeable increase in the nuclei size and the crystallinity fraction increases to 40%. Annealing of a-Ge (6 nm) nanolayers embedded in a-Si matrix under the same conditions for 2 and 4 hours does not even lead to partial crystallization, the layers remain amorphous. The influence of interfaces on the crystallization of germanium layers is discussed.

The physicochemical parameters of spherical amorphous nanoparticles (SANPs), consisting of a mixture of triterpenoids of birch bark (MTB) with 20-hydroxyecdysone (20E), are studied. The nanoparticles are obtained by injection and investigated by electron microscopy, dynamic light scattering, and UV spectroscopy. In the studied series of concentrations of 20E from 5 to 20 wt %, in relation to the mass of the MTB, the optimal concentration is 20E 10 wt %; at this concentration, the most stable nanodispersions are formed in water, 20E is fully included in the SANPs, their average size is 193.1 nm, they are characterized by a narrow polydispersity interval, and they have the greatest absolute value of the ζ-potential. Ecdysteroid-containing SANPs of this composition can be recommended for use in medicine as prolonged forms of ecdysteroids as radioprotective and other pharmacological agents.

This work was devoted to studying the atomic structure and electron spectrum of a-SiOx : H films created on silicon and glass substrates by means of plasma-enhanced chemical vapor deposition (PECVD). Depending on the conditions of oxygen supply into the reactor, the stoichiometric parameter x of the films was varied from 0.57 to 2. The structure of the films and the specific features of their electron structure were characterized depending on the parameter x with a complex of structural and optical methods and ab initio quantum-chemical simulation for the model SiOx structure. The studied SiOx : H films were established to consist predominantly of silicon suboxides SiOy, SiO2 clusters, and amorphous silicon. Based on the spatial fluctuations of their chemical composition, the model of bandgap width and potential fluctuations was proposed for SiOx electrons and holes. The obtained data would provide the charge transport in a-SiOx : H films with more precise modeling important for the creation of nonvolatile random-access memory (RAM) elements and memristors on their basis.

Composites consisting of Ge nanoclusters embedded in GeO2 matrix were modified by selective removal of the germanium dioxide in deionized water or HF. Thin (up to 200 nm) and thick (300−1500 nm) GeO2{Ge-NCs} heterolayers were studied before and after the etching using Raman spectroscopy, scanning and spectral ellipsometry, scanning electron microscopy. It was found that a stable skeletal framework from agglomerated Ge nanoparticles (amorphous or crystalline) was formed after the etching of thin GeO2{Ge-NCs} heterolayers. When removal the GeO2 matrix from a thick GeO2{Ge-NCs} heterolayer, released Ge nanoclusters were arranged in a vertically ordered chains.

We have developed a model for calculating the Raman spectra for optical phonons localized in diamond nanocrystals. The novelty of this approach is that it includes the contribution of localized phonons with dispersion over the entire Brillouin zone (3D model). The model is refined in that the phonon dispersion is calculated in the well-tested bond-charge model. The effects of the contribution to the Raman spectra from longitudinal optical phonons with frequencies higher than their frequency at the center of the Brillouin zone are considered. Comparative analysis of the calculated spectra and experimental spectra obtained from nanopowders and nanocrystalline diamond film is performed.

In present study nanocomposites of Graphene Like Material (GLM) and nickel containing 5–60 wt % Ni were prepared by a co-reduction of graphite oxide and Ni2+ ions. These nanocomposites served as effective catalysts of hydrogenation-dehydrogenation of magnesium based materials and showed a high stability on cycling. Composites of magnesium hydride with Ni/GLM were prepared by high-energy ball milling in hydrogen. The microstructures and phase compositions of the studied materials were characterized by XRD, SEM and TEM showing that Ni nanoparticles have size of 2–5 nm and are uniformly distributed in the composites. The kinetic curves of hydrogen absorption and desorption by the composites were measured using a Sievert's type laboratory setup and were analyzed using the Avraami – Erofeev approach. The re-hydrogenation rate constants and the Avraami exponents fitting the kinetic equations for the Mg/MgH2+Ni/GLM composites show significant changes as compared to the Mg/MgH2 prepared at the same conditions and this difference has been assigned to the changes in the mechanism of nucleation and growth and alteration of the rate-limiting steps of the hydrogenation reaction. The composites of Mg with Ni/GLM have a high reversible hydrogen capacity exceeding 6.5 wt % H and also show high rates of hydrogen absorption and desorption and thus belong to the promising hydrogen storage materials.

The optical properties of float-zone (FZ) silicon irradiated with swift heavy ions (SHI) are studied. In the low-temperature photoluminescence spectra, a broad peak in the range 1.3–1.5 μm is evident along with the well-known X, W, W', R, and C lines. In this case, it is found that, as the irradiation dose is increased in the range 3 × 1011–1013 cm–2, the photoluminescence peak falls and narrows and, at the same time, its maximum shifts to longer wavelengths.

The solvent extraction technology is a promising method for recovery of unconventional oil resources because of its high efficiency, low energy consumption, and high compatibility. Solvent selection and solvent loss are the main limitations in terms of industrialization of the technology. To evaluate the solvent, efficient detection of the residual solvent content in the extracted-oil gangue is also a problem. A solvent extraction-gas chromatography (GC) combined method is proposed for fast determination of residual organic solvent in extracted-oil ore gangues (mixed with process water). To improve the precision, a combination of the external standard method and the internal standard method (ES&IS method) was applied. This analytical method shows a relative standard deviation (RSD) of less than 2%. The recovery of residual solvent was in the range of 95.4 ~ 102.0 wt% (for a spiked organic solvent content of 0.5 to 25.0 wt%). It is also found that whatever types of solvent (ethanol, tetrahydrofuran, cyclohexane, n-heptane, acetone, ethyl acetate, or toluene) are used, the method detection limit (MDL) can be less than 0.023 mg/mg. The whole procedure of this method, including the pretreatment and instrumental detection, can be finished in-situ in a relatively short time (less than 1.5 hours). On the other hand, due to the simple application of solvent extraction pretreatment and GC detection, this measurement can be a low-cost one. Therefore, it can be applied to solvent selection and solvent recovery method evaluation and propel the industrialization of the solvent extraction technology.

Ion-plasma sputtering and codeposition of ultrafine particles of hafnium and carbon were used to produce film coatings in the concentration ranges of 5.3–59.8 at % C. Structural investigations revealed the existence of Hf–C solid solutions in the concentration range of 5.3–11.5 at % C. In the concentration range of 21.5–59.8 at % C, the coatings consist of the hafnium-carbide phase; and at 16.2 at % C, both phases coexist. The lattice parameters of the phases present in the films and their variation depending on the carbon concentration have been determined. The dependence of the HfС lattice parameter in the range of 16.2–35.0 at % C on the nature of the substrate on which the coating is deposited has been established. The solid solutions of carbon in hafnium exhibit conductivity of metallic type; the resistance of the hafnium carbide almost does not change upon cooling from 300 to 11 K. The direct synthesis of hafnium carbide HfC by a codeposition of nanoparticles on the surface of products can be used as a technological method.

Solid solutions of cadmium in niobium and NbCd2 phase are formed by magnetron sputtering and coprecipitation on substrates moving relative to the flow of Nb and Cd particles. The NbCd2 phase can be described by a tetragonal unit cell with the parameters a = 0.84357 nm, c = 0.54514 nm, and c/a = 0.6426. A very high hole concentration in NbCd2 is established by studying the coating absorption and transmission spectra corresponding to the intermetallic-compound composition near the fundamental absorption edge, determining the band gap, and measuring the carrier mobility. Such a concentration is characteristic of a strongly degenerate semiconductor or metal. The band gap is determined to be 1.26 eV. The variation in the concentration of carriers and their mobility depending on the cadmium concentration in coatings of the Nb–Cd system confirms the occurrence of the NbCd2 phase.

Zirconium oxide was obtained via traditional precipitation from a ZrOCl2 solution with ammonia followed by drying at 110 °C. The carbon-coated samples were synthesized by calcination of the pristine zirconia mixed with polyvinylalcohol. The obtained ZrO2@C samples of core-shell structure as well as the reference samples of pristine zirconia were calcined at different temperatures from 500 to 1400 °C. All the materials were examined by a set of physicochemical methods (a low-temperature argon adsorption, transmission electron microscopy, X-ray diffraction analysis, photoluminescence spectroscopy). It was found that the carbon coating prevents the sintering of the oxide nanoparticles, which allows one to maintain the specific surface area, the size of the oxide core and, finally, stabilize its phase composition. Transformation of the cubic phase into monoclinic phase becomes significantly complicated. Thus, 40% of the cubic phase was detected even after calcination of the ZrO2@C sample at 1400 °C. Moreover, the carbon-coated samples treated at elevated temperatures with subsequent removal of the carbon shell were found to possess the highest concentration of the defects related to a presence of the anion vacancies in zirconia.

Lanthanum and zirconium oxides are well known to be applied as an additive to improve the properties of the commercial alumina. Such modified aluminas are widely used in different catalytic fields including three-way catalysis. In the present research we have paid attention to the possible effects of the doping on the catalytic performance and stability of bimetallic Pd-Rh catalysts. The samples were prepared via an incipient wetness impregnation of the commercial supports, tested in CO oxidation under prompt thermal aging regime and characterized by physicochemical methods.

The Raman spectra of SiO2 films containing InSb spherical nanocrystals produced by ion-beam synthesis are studied. TO- and LO-like modes in the spectra of the InSb nanocrystals are detected at frequencies of 187 and 195 cm–1, respectively. The shift of these modes to high frequencies with respect to the corresponding frequencies in InSb bulk crystals is analyzed from the viewpoint of the influence of the quantum-confinement effect, strains in nanocrystals, the surface phonon frequency, and scattering at the frequency corresponding to stretched anion–cation modes at the surface of polar spherical nanocrystals. The position of the 195-cm–1 mode corresponds to LO phonons in InSb nanocrystals hydrostatically compressed in the SiO2 matrix at pressures of about 10 kbar. The 187-cm–1 mode corresponds to resonance at the Frohlich frequency.

Ta–Be solid-solution–alloys have been obtained for the first time by ion-plasma sputtering and co-deposition of ultradispersed Ta and Be particles in the range of concentrations of Be from 1.1 to 85.8 at % in the film, which is a confirmation of the thermofluctuation melting and coalescence of small particles. A regular character of changes of the unit-cell volume of the solid solution of Be in β-Ta has been established. Upon the vacuum annealing at 800°C of a sample with Be concentration at a level of 26.8 at %, there was a new phase, identified as Ta3Be, with a tetragonal face-centered lattice with p arameters a = 0.7579 ± 0.0003 nm and c = 0.7370 ± 0.0005 nm. The X-ray diffraction data for the identification of this intermetallic compound are given. The performed electron-microscopic investigations have shown that the thermal expansion coefficient of the Ta3Be phase is greater than that of the solid solution of Be in β-Ta. The study of the temperature dependence of the electrical resistance of the Ta3Be phase upon cooling from room temperature to 10 K has shown that this phase has a metallic character of the R(T) dependence. The Ta3Be phase does not possess superconducting properties down to 10 K.

The processes of the crystallization of amorphous germanium films and multilayer germanium/silicon structures upon exposure to nanosecond (70 ns) ruby laser radiation (λ = 694 nm) are studied. The samples are grown on silicon and glassy substrates by plasma-enhanced chemical vapor deposition. Pulsed laser annealing of the samples is conducted in the range of pulse energy densities Ep from 0.07 to 0.8 J cm–2. The structure of the films after annealing is determined by analyzing the scanning electron microscopy data and Raman spectra. It is established that, after annealing, the films are completely crystallized and, in this case, contain regions of coarse crystalline grains (>100 nm), whose fraction increases, as Ep is increased, and reaches 40% of the area. From analysis of the position of the Raman peaks, it is conceived that the crystalline grains, whose dimensions exceed 100 nm, either contain structural defects or stretching strains. The correlation length of optical vibrations is determined from the phonon confinement model and found to increase from 5 to 8 nm, as Ep is increased. Pulsed laser annealing of multilayer Ge(10 nm)/Si(5 nm) structures induces partial intermixing of the layers with the formation of Ge–Si alloys.

Tensile-strained germanium films in Ge/GeSn/Si/GeSnSi multilayer heterostructures grown by molecularbeam epitaxy on Si(001) substrates are investigated by Raman spectroscopy. Biaxial tensile strains in the films reach 1.5%, which exceeds values previously obtained for this system. Splitting of frequencies of long-wavelength optical phonons is experimentally observed; i.e., the shift of the frequency of the singlet induced by biaxial tensile strains is larger than the shift of the frequency of the doublet in agreement with calculations. The strain-induced shift of Raman scattering peaks from two-phonon scattering in germanium is also detected.

Films of nonstoichiometric germanium–silicon glasses of two types—GeOx[SiO](1 – x) and GeOx[SiO2](1 – x)—are deposited onto cold Si (001) substrates by evaporating GeO2 and SiO (or SiO2) powders simultaneously in high vacuum. Film samples in their initial (as-deposited) state and after being annealed at 550 and 650°C for 1 h are investigated using IR and Raman spectroscopies and electron microscopy, and their photoluminescence (PL) is studied as well. Raman spectroscopy shows that, in contrast to the initial GeO[SiO2] film, the initial GeO[SiO] one contains clusters of amorphous germanium, their size being ~3 nm, as found by electron microscopy. The presence of Si–O, Ge–O, and Si–O–Ge bonds in the films is established by IR spectroscopy. Clusters of amorphous germanium are found in both films after annealing at 550°C, while germanium nanocrystals are formed in the films subjected to annealing at 650°C. For the initial films, a broad band with a maximum at 1050 nm is registered in their low-temperature PL spectra, which may originate from such defects as oxygen vacancies and overstoichiometric germanium atoms. Annealing causes structural changes in the films and affects their PL behavior. The films containing germanium nanoclusters give rise to PL with a maximum at 1400–1600 nm, with the defect-related signal being diminished. The temperature dependence of PL intensity exhibits a decreasing behavior, but PL is observed to temperatures as high as 200 K. The contribution of germanium nanocrystals formed at the annealing stage to PL is discussed.

Nonstoichiometric GeO0.5[SiO2]0.5 and GeO0.5[SiO]0.5 germanosilicate glassy films are produced by the high-vacuum coevaporation of GeO2 and either SiO or SiO2 powders with deposition onto a cold fused silica substrate. Then the films are subjected to furnace or laser annealing (a XeCl laser, λ = 308 nm, pulse duration of 15 ns). The properties of the samples are studied by transmittance and reflectance spectroscopy, Raman spectroscopy, and photoluminescence spectroscopy. As shown by analysis of the Raman spectra, the GeO[SiO] film deposited at a substrate temperature of 100°C contains amorphous Ge clusters, whereas no signal from Ge–Ge bond vibrations is observed in the Raman spectra of the GeO[SiO2] film deposited at the same temperature. The optical absorption edge of the as-deposited GeO[SiO2] film corresponds to ~400 nm; at the same time, in the GeO[SiO] film, absorption is observed right up to the near-infrared region, which is apparently due to absorption in Ge clusters. Annealing induces a shift of the absorption edge to longer wavelengths. After annealing of the GeO[SiO2] film at 450°C, amorphous germanium clusters are detected in the film, and after annealing at 550°C as well as after pulsed laser annealing, germanium nanocrystals are detected. The crystallization of amorphous Ge nanoclusters in the GeO[SiO] film requires annealing at a temperature of 680°C. In this case, the size of Ge nanoclusters in this film are smaller than that in the GeO[SiO2] film. It is not possible to crystallize Ge clusters in the GeO[SiO] film. It seems obvious that the smaller the semiconductor nanoclusters in an insulating matrix, the more difficult it is to crystallize them. In the low-temperature photoluminescence spectra of the annealed films, signals caused by either defects or Ge clusters are detected.

The formation of InSb nanocrystals at the bonding Si/SiO2 interface of silicon-on-insulator structure was obtained as a result of the In and Sb atom diffusion from the ion-implanted SiO2 and Si regions, respectively, toward the interface. After the annealing at 1000 °C, the Raman scattering peaks corresponding to the transverse and longitudinal optical phonon mode in the monocrystalline InSb matrix were obtained. As the annealing temperature grew to 1100 °C, the transverse optical phonon mode vanished and the longitudinal optical phonon mode dominated in the spectrum. This effect is explained by matching InSb and Si lattice constants under ion-beam synthesis conditions.

The phase transitions during the oxidation of polycrystalline tin (β-Sn) were studied. The intense photoluminescence from SnO was observed in the annealing temperature range of 300–400 °C. An increase in the annealing temperature led to a sharp decrease in photoluminescence. It is associated with the phase transition of SnO to SnO2. Two approaches were proposed for obtaining the dual-band material based on tin oxides and GeSiSn compounds. Using the Sn-rich nanoislands grown on the vapor–liquid-solid (VLS) mechanism, the nanoislands having SnO(x) in their upper part, and the SiSn solid solution under SnO(x) were obtained after annealing. Furthermore, the growth technology of the dual-band material, which included tin oxides on top of a GeSiSn/Si multiple quantum well (MQW) structure, was developed. Tin oxides demonstrated the photoluminescence signal in the visible region, whereas the SiSn solid solution in nanoislands and GeSiSn/Si multiple quantum well structure showed the photoluminescence signal in the infrared range.

Ion-plasma sputtering and code position of Mo and Cd ultrafine particles have been used for the first time to prepare solid solutions that are alloys with a concentration up to 57.3 at. % Cd in the film; this confirms the thermal-fluctuation and coalescence of small particles. When coatings are formed by molyb-denum and cadmium nanolayers less than 2 nm in the concentrations range of 60-66 at. % Cd, a new phase was found that was prepared directly in the course of film coating formation; it was identified as the MoCd 2 compound with a tetragonal face-centered lattice, with the parameters a = 0.78231 nm and c = 0.77039 nm. X-ray diffraction data for the identification of the intermetallic compound were determined. The unit cell of MoCd 2 has been constructed. Upon accumulation in the lattice, cadmium first replaces the molybdenum atom in the center of the unit cell, then another cadmium atom is embedded in the molybdenum lattice, replacing the atom at one of the cube corners and accompanied by a cubicto-tetragonal cell transformation where the cadmium atoms are embedded in pairs on the side faces of the cell in the MoCd 2 compound. Thermal stability of the intermetallic compound is limited by 200 ◦ C. Synthesized phase of MoCd 2 has a metallic type of conductivity.

A series of the Rh-containing samples supported on pure γ-Al2O3, La-doped γ-Al2O3, LaAl11O18 and LaAlO3 was prepared and characterized. Diffusion of Rh3+ ions from the surface of the support into its bulk causing the rapid deactivation of the catalyst in a model reaction of CO oxidation under the prompt thermal aging conditions was shown to be accelerated by a presence of lanthanum. The amount of rhodium disappeared from the surface during the high temperature treatment was estimated by a testing reaction of ethane hydrogenolysis and an electron paramagnetic resonance spectroscopy with spin probe. In order to characterize rhodium ions diffused into the bulk of the support at different calcination temperatures, the optical spectroscopic methods (diffuse reflectance UV–vis and photoluminescence spectroscopies) were applied. Rh3+ ions were shown to be applicable as a luminescence probe to follow the process of their bulk diffusion and localization within the matrix of the support, as well as for the structure identification of the La-containing sites responsible for the alumina thermal stabilization. The obtained data on luminescence of Rh3+ ions indicate that already at 800 °C the oxygen octahedrons corresponding to LaAl11O18 structure are being formed in the local coordination surroundings of isolated La ion in the 4%La2O3-Al2O3 support. It is important to notice that the structures of such kind can be formed in La-doped aluminas only. There are no octahedron positions with sufficient values of the crystal field for the formation of luminescence centers of Rh3+ ions in pure γ-Al2O3.

—The ferromagnetic resonance in an array of permalloy microstrips 3000 × 500 × 30 nm3 in size, which are ordered on a rectangular 3.5 × 6 μm2 lattice, is studied using magnetic resonance force microscopy with strong probe–sample interaction. This interaction induces intricate modifications of the observed spectra, which are manifested both in line splitting and in changes in shape. The dependences of the observed spectra on the sample–probe distance and the orientation of the magnetic moment of the probe are analyzed.

Heavily boron doped nanocrystalline diamond films grown on glass substrates by the method of plasma-chemical deposition, were investigated using Raman spectroscopy. Analysis of the spectra showed both the phonon confinement effect in nanocrystalline grains and Fano interference effect due to the contribution of electron Raman scattering in heavily doped p-type diamond films. The increase of boron concentration led to decrease of the size of crystalline diamond grains. The films are semitransparent and have good conductivity, so that it can be used as transparent electrodes in giant-scale electronics and optoelectronics.

Tailoring magnetic properties in nanocluster assembled cobalt (Co) thin films was achieved by admitting a small percentage of H2 gas (∼2%) into the Co gas phase cluster formation chamber prior to deposition. The oxygen content in the films is considerably reduced by the presence of hydrogen during the cluster formation, leading to enhanced magnetic interactions between clusters. Two sets of Co samples were fabricated, one without hydrogen gas and one with hydrogen gas. Magnetic properties of the non-hydrogenated and the hydrogen-treated Co nanocluster assembled films are comparatively studied using magnetic force microscopy and vibrating sample magnetometry. When comparing the two sets of samples the considerably larger coercive field of the H2-treated Co nanocluster film and the extended micrometer-sized magnetic domain structure confirm the enhancement of magnetic interactions between clusters. The thickness of the antiferromagnetic CoO layer is controlled with this procedure and modifies the exchange bias effect in these films. The exchange bias shift is lower for the H2-treated Co nanocluster film, which indicates that a thinner antiferromagnetic CoO reduces the coupling with the ferromagnetic Co. The hydrogen-treatment method can be used to tailor the oxidation levels thus controlling the magnetic properties of ferromagnetic cluster-assembled films.

The effect of the annealing temperature on the optical and structural properties of the a-SiOx:H thin films prepared by gas-jet electron beam plasma chemical vapor deposition method was studied. Annealing was carried out at 600, 700, 800, 900 and 1000 °C for 4 h in oxidizing atmosphere. According to FTIR spectroscopy measurements, the oxygen and hydrogen concentration in the as-deposited films was 25 at.% and 2 at.%, respectively. The SEM image showed that the as-deposited material had column structure with a large number of vertical voids. As a result of annealing, the thickness of the films decreased by approximately 1.5 times for all samples. The value of refractive index at 650 nm decreased from 2.5 to 2.0 with the increase of the annealing temperature. The E04 optical gap decreased in comparison with the value of the as-deposited thin films for 600 °C and 700 °C, and increased for 800–1000 °C. For annealing at a temperature of 600 °C, the structure of the material changes insignificantly. A rearrangement in the structure of the matrix with the formation of amorphous silicon nanoclusters occurs at 700 °C and 800 °C. Annealing at the higher temperatures leads to transition from a material with amorphous nanoclusters to a material with nanocrystallites.