AbstractThe features of the formation of the surface morphology of polyethylene terephthalate under the influence of a high-power ion beam of nanosecond duration are investigated. It is established that in the case of a single exposure of such a beam to polyethylene terephthalate, as well as for the majority of other polymers, pores are formed in the surface layer; however, their number is much less. Significant differences begin to appear when the polymer is repeatedly irradiated with a high-power ion beam. For most polymers this leads to an increase in the surface porosity and partial local destruction of the surface layer. Under such irradiation conditions, various spatial structures are formed on the surface of polyethylene terephthalate, the type and sizes of which depend on the number of irradiation pulses. X-ray microanalysis of the surface layer shows a significant (1.4 times) decrease in the oxygen content after ion irradiation. The irradiation of polyethylene terephthalate by a high-power ion beam does not result in the formation of a thin carbon layer on its surface. The possible reasons for the formation of such a surface morphology under the action of a high-power ion beam on polyethylene terephthalate are considered.

AbstractThe results of spectral analysis of the surface of polysulfone fiber (channel) after transmission of a 10-keV electron beam through it are presented in this work. This work is a continuation of the study of the dependence of the quantity of electrons transmitted without loss of energy through the array formed of polysulfone hollow fibers, on the angle of rotation of the array about the vertical axis. Data of the analysis demonstrates significant modification of the internal surface of the channel after its electron irradiation. It is made clear that, in the case of the long-term irradiation of polysulfone tubes by charged-particle beams, a dark coating is formed on the surface layer of the channel which can have a significant impact on the transmission capacity and controllability of the channels in the context of the control of charged particles. Comparison of the elemental composition of the surface of the fiber before and after the grazing interaction of a beam of electrons with an energy of 10 keV with it reveals an increase in the carbon concentration in the irradiated fiber of 50 wt %, and an oxygen content increase of 40 wt %. The sulphur amount does not change, and remains at the level of about 10 wt % both in the irradiated and in nonirradiated sample.

AbstractThe paper presents the results of a study of syndiotactic polymethyl methacrylate with a molecular weight of 107 g/mol, synthesized by the method of ionic polymerization with radiation initiation. Changes in the chemical structure of the polymer material were analyzed by means of IR spectroscopy, differential thermal analysis, and gel permeation chromatography. The process of weight loss during thermal decomposition of the initial polymer can be divided into three stages: low-temperature, medium-temperature, and high-temperature ones. After exposure of the polymer even to minimum doses of ionizing radiation, there is no pronounced thermal effect of polymer melting. A scatter in the molecular sizes was found, as well as a relatively rapid decrease in the molecular weight under the action of X-rays in the dose range of up to 100 J/cm3. Polydispersity at low doses is approximately 3.5 times higher than that at doses on the order of 10 kJ/cm3. The achieved rate of latent image development was approximately five times compared with the polymer with a molecular weight of 106 g/mol under standard conditions. The contrast was 3.4. Microstructuring was performed by the X-ray lithography method on the VEPP-3 source with the use of synchrotron X-rays. The resulting microstructures are up to 5 µm high and about 2 µm in diameter.

AbstractWe present the results of the synthesis of nanoclusters of metallic zinc and its oxide in crystalline quartz implanted with 64Zn+ ions with a dose of 5 × 1016 cm–2 and energy of 40 keV and annealed in oxygen at 400–900°C. Scanning electron microscopy combined with energy-dispersive spectroscopy, Rutherford backscattering spectroscopy and photoluminescence are used for the study. After implantation, separate nanoclusters of metallic zinc with a size of less than 1 μm are detected on the surface and in the surface layer of quartz. During annealing, metallic zinc passes to the phases of its oxide ZnO and silicate Zn2SiO4. After annealing at 700°C (optimal for obtaining the ZnO phase), zinc-oxide nanoclusters smaller than 500 nm are formed in the quartz surface layer. The photoluminescence spectrum exhibits a doublet peak at a wavelength of 370 nm, which is due to exciton luminescence in zinc oxide. After annealing at 800°C, the ZnO phase degrades, and the zinc silicate Zn2SiO4 phase is formed.

AbstractWe study the structure of a zinc coating on steels with a silicon concentration of 0.02, 0.06, 0.20, and 0.67 wt %. The coating is applied by dipping into a pure zinc melt and in a zinc melt with 0.05 wt % of nickel for 5 min at a temperature of 450°С. The features of the morphology of the ζ phase of the coating are found depending on the silicon concentration in the steel. With a silicon concentration of 0.06 wt %, the ζ phase is presented by branched dendrites growing to the surface. This leads to the so-called “Sandelin effect”, when the coating thickness is not the same over the entire surface of the substrate. On high-silicon steels (with a silicon concentration of 0.67 wt %), the ζ phase consists of large crystallites and makes up 90% of the entire coating thickness. Growth of the coating phases is effectively suppressed by alloying the zinc melt with nickel in an amount of 0.05 wt %. We find a change in the structure of the individual phases of the coating upon alloying the zinc melt. Energy-dispersive microanalysis revealed coating areas with a jump in the nickel concentration up to 0.33 wt %. Interpreting the Kikuchi patterns shows that the initial structural type of the ζ phase of the coating is kept for all steels and corresponds to the FeZn13 intermetallic compound with a monoclinic crystal lattice, in which 0.30–0.33 wt % of iron is replaced by nickel. A finely dispersed mixture of phases is found in the coating on high-silicon steel, located between the crystallites of the δ phase and ζ phase with an increased concentration of silicon (0.61 wt %) and nickel (0.2 wt %). The coincident Kikuchi patterns and the small values of the average angular deviation confirm the detection of Fe3Zn10, FeZn13, and Ni2Zn3Si intermetallic compounds.

AbstractA technology is developed for producing thin films of CuGaSe2 by the method of two-step selenization when the reaction component (selenium) is delivered by a flow of a carrier gas (nitrogen). The effects of the temperature of selenization on the surface morphology, composition, and structure of CuGaSe2 films are studied by electron microscopy and X-ray-diffraction phase analysis. Based on X-ray photoelectron spectroscopy data on the transformation of chemical states of the components, the influence of the temperature of selenization on the phase-formation process in films is analyzed.

AbstractThe work presents the results of studying the effect of irradiation of the surface of hypoeutectic silumin with a pulsed electron beam on the mechanical properties of the material. Silumin of grade AK5M2 (Al–(4.0–6.0) Si–1.3 Fe–0.5 Mn–0.5 Ni–0.2 Ti–2.3 Cu–0.8 Mg–1.5 Zn) is used as a test material. To carry out uniaxial tensile deformation, double-sided proportional samples with heads are made. The results of studying the evolution of strain fields of layered composites silumin/carbon-fiber-reinforced plastic (CFRP) based on irradiated silumin in uniaxial tension are also presented. The carbon fiber is made of a filler (FibARM Tape-230 unidirectional carbon fabric) and a binder (FibARM Resin 530 two-component epoxy compound). The fracture surface of the samples is studied using scanning-electron-microscopy techniques. The dependences of the maximum and minimum values of strains in the localizers on the sample surface on the averaged strains over the working area of the sample are plotted. An increase (relative to silumin in the initial state) in the strength and plastic properties of both samples of irradiated silumin and of the silumin/CFRP composite is determined. The sawtooth character of the deformation curve of uniaxial tension of the silumin/CFRP composite material with a pre irradiated surface of the silumin plate is revealed.

AbstractThe development of modern technologies, including nanotechnology, is based on the application of methods for the diagnostics of objects used in technologies processes. For this purpose, most promising methods are those implemented using a scanning electron microscope. Moreover, one of the basic methods is the measurement of linear sizes of relief structures of micrometer and nanometer ranges used in microelectronics and nanoelectronics. The basis of operation of scanning electron microscopes is the secondary electron emission of a solid body. However, practically all known regularities of secondary electron emission have been obtained for surfaces, the relief of which was neglected. A review of theoretical and experimental materials of studying the secondary electron emission of solid bodies on surfaces without a relief is given. Practically all known regularities have been verified in experiments and have received their own physical explanation. However, the application of secondary electron emission in scanning electron microscopy, used in microelectronics, nanoelectronics and nanotechnology, requires knowledge of the regularities, which emerge on relief surfaces. The regularities that can be applied in a scanning electron microscope to measure the linear sizes of relief structures are demonstrated. A conclusion is drawn as to the necessity of studying the influence of the surface relief of a solid body on secondary electron emission.

AbstractThe results of studying the morphology and crystalline, local atomic, and chemical structure of iron(III) oxide coatings on the surface of porous aluminum oxide with different morphology using methods of scanning-electron- and atomic-force microscopy, X-ray phase analysis, X-ray photoelectron spectroscopy, as well as X-ray absorption near edge structure (XANES) spectroscopy are presented. Films of porous alumina are synthesized by the two-stage anodic oxidation of aluminum in 0.3 M aqueous solutions of sulfuric and oxalic acids. To change the pore diameter, some of the films are etched in a phosphoric-acid solution. Samples of iron oxide nanocoatings are obtained by oxidation of iron films in air deposited onto porous alumina substrate matrices by magnetron sputtering at a temperature of 300°C for 3 h. It is shown that oxidation leads to a twofold increase in the coating thickness of the control sample and is associated with an increase in the density of iron oxide compared to pure iron. With a change in the nanoporous structure on the surface of the substrates, the morphological features of the coatings change: there is overgrowth of the pores with iron oxide. Controlling the processes leading to such overgrowth will make it possible to carry out a targeted change in the structure-sensitive properties of composite structures based on iron oxide.

AbstractThe effect of the electron-irradiation temperature on radiation-defect formation in silicon carbide is studied for the first time. Commercial high-voltage 4H-SiC Schottky diodes are studied. Irradiation is carried out by electrons with an energy of 0.9 MeV at temperatures of 20°C and 200°C. The spectra of radiation-induced defects are measured using nonstationary capacitance spectroscopy. It is established that with an increase in the temperature of irradiated silicon carbide, not only the number of introduced radiation defects decreases, but also their spectrum changes. If cold irradiation leads to the formation of six deep traps, then hot irradiation leads to the formation of only three traps: Z1/Z2 (0.68 eV), EH5 (1.08 eV), and EH6/EH7 (1.58 eV). During hot irradiation the number of induced radiation defects also sharply decreases, which leads to a decrease in the rate of removal of charge carriers (compensation of semiconductor conductivity) by almost four times: from 0.25 to 0.065 cm–1. It is noted that nonlinear effects in radiation-defect formation are observed in silicon carbide. At a fixed dose of irradiation of silicon carbide by electrons, the number of introduced radiation defects depends on the electron-flux density (dose-accumulation time).

Abstract—A uniformly moving charged particle generates transition radiation when moving in an inhomogeneous medium (in particular, when crossing the interface between two media) and diffraction radiation when moving near medium inhomogeneities without crossing their boundaries. Both diffraction and transition radiation can be used to detect particles and monitor beams in accelerators. While methods based on the transition radiation of particles for diagnostics of both relativistic and nonrelativistic beams are widespread, the application of diffraction radiation for these goals remains the subject of research. Diffraction-radiation generation weakly perturbs the motion of a particle beam, which makes it possible to develop nondestructive beam-diagnostics methods. The description of the diffraction radiation of a nonrelativistic charged particle for a conducting sphere was constructed earlier by means of the image method known from electrostatics. The method for finding the parameters of particle flight by the sphere was proposed within the framework of this approach; it used a single point detector recording the intensity and polarization of diffraction radiation. Here we propose a scheme with three detectors that solves the same problem without recording the radiation polarization.

AbstractA relationship is established between the crystallographic texture developed during various thermomechanical treatments and the functional properties of titanium-based alloys, in particular, titanium nickelide obtained by sintering calcium-hydride powder. The thermomechanical treatment of sintered workpieces is carried out by rotary forging, radial shear rolling, or extrusion. The temperature of the last stage of deformation in all cases is 900°C. The neutron diffraction analysis of the samples is performed on the SKAT texture diffractometer at the Joint Institute for Nuclear Research (Dubna, Russia). The projection plane of the experimental pole figures is perpendicular to the sample axis and the deformation axis. The shape memory characteristics are determined by torsion deformation on wire samples cut from rods along the axis. The texture is most fully demonstrated by the sample after extrusion: the volume fraction of textured grains reaches 85%, and the maximum pole density is 2.76 m.r.d. (multiple of a random distribution). The functional properties under torsion deformation γpore = 2–16% are studied. Extruded samples and samples subjected to radial shear rolling demonstrate the best superelasticity in the austenitic phase γsuper = 15% and maximum values of the critical stresses γcr = 15%, starting from which the deformation becomes irreversible. The relationship between the sharpness of the crystallographic texture and the functional properties of the TiNi alloy after thermomechanical treatment is revealed.

AbstractThe paper focuses on the synthesis of gadolinium-doped ceria (CexGd1 – xO2 – y) thin films on the anodes of solid oxide fuel cells by reactive dual magnetron sputtering. CexGd1 – xO2 – y thin films 4 μm thick are deposited in the transition and oxide modes, differing by the oxygen concentration in the vacuum chamber. Residual stresses after the film deposition and thermal annealing in air are determined by the curvature of the anode plates. Dependences are obtained between the deposition modes, residual stresses and parameters of fuel cells with the CexGd1 – xO2 – y electrolyte. The surface morphology and cross-section of the films are studied on a scanning electron microscope. The X-ray diffraction analysis is additionally conducted to study the structure of gadolinium-doped ceria thin films using the synchrotron radiation during 1300°С annealing. It is shown that under certain conditions of the film deposition and annealing, compressive stresses can transfer to tensile stresses, which reduces the anode plate deformation after the CexGd1 – xO2 – y electrolyte deposition.

AbstractOsmium compounds with the Os 5d 4 electron configuration and an octahedral environment of neighboring atoms attract much attention due to the influence of the spin-orbit interaction on the appearance of magnetic properties in materials. X-ray absorption near edge structure (XANES) spectroscopy makes it possible to obtain information about the value of the spin–orbit interaction from measuring the intensity ratio of lines near the absorption edges. The influence of the spin–orbit interaction on the Os L2,3-edge XANES spectra of osmium compounds having an octahedral environment of halogen atoms is studied. Two types of systems are investigated, namely, isolated osmium clusters in complex compounds and the OsCl4 compound containing Os polymer chains bridged by Cl atoms. Magnetic-susceptibility measurements show a nonmagnetic ground state and Van Vleck paramagnetism in the case of isolated clusters and a nonzero magnetic moment over the entire temperature range in OsCl4. As a result of measurements of the XANES spectra, high values of the line intensity ratio are obtained near the Os L3/L2 absorption edges, which is associated with the strong effect of the spin-orbit interaction on the electronic structure. The theoretical analysis of the XANES spectra of Os compounds with different ligands and outer-sphere cations shows that the electronic structure and magnetic properties depend on the spin–orbit interaction, the crystal-field splitting, the electron-pairing energy, and noncubic distortions of the Os environment.

AbstractThe fast periodic pulsed research reactor IBR-2 started operating in 1982 at the Joint Institute for Nuclear Research in Dubna, Russian Federation. IBR-2M was successfully upgraded and restarted in 2012. The third-generation neutron source reactor IBR-2M has the world’s highest neutron flux per pulse. A new neutron source (the NEPTUN reactor) is currently being designed to replace IBR-2M after it is out of service. The NEPTUN reactor is a fourth-generation pulsed neutron source that uses Np-237 as a nuclear fuel for the first time. The optimization of the thermal moderator (water moderator) of the NEPTUN reactor is considered in order to obtain the highest thermal neutron flux on the extracted neutron beam. It is shown that the increase in water thickness leads directly to a shift of faster neutrons towards thermal spectra, but the maximum neutron flux can be obtained only at an optimum thickness.

AbstractTo assess the resistance of polymer nanocomposites to the effects of atomic oxygen in low Earth orbits, we study the effect of oxygen plasma on the structural and optical properties of an epoxy resin with the addition of graphene and Taunit-M carbon nanotubes. Introducing carbon fillers to epoxy resin increases the weight loss and erosion depth when exposed to oxygen plasma. The weight erosion coefficient at an atomic-oxygen fluence of 30 × 1020 cm–2 is 0.82 × 10–23 g/at for pure epoxy resin and 0.86 × 10–23 and 1.06 × 10–23 g/at for samples with graphene and Taunit-M, respectively. In the case of the sample with the Taunit-M filler, a greater weight loss and erosion depth are observed as a result of irradiation in oxygen plasma in comparison with the sample with the graphene filler. The treatment of carbon nanocomposites in oxygen plasma significantly decreases the reflectance coefficients in the spectral range of 0.2–2.5 µm. The lowest diffuse (less than 1%) and specular (less than 0.02%) reflectance coefficients are registered for the irradiated polymer with Taunit-M.

AbstractThe results of using the statistics of multiple scattering to describe the dependence of the stopping power S of matter on the energy E0 of a beam of alpha particles are presented. It is shown that the application of a new technique based on taking into account the dependence of the charge state of beam ions on the ratio of the ion velocity to the minimum velocity of substance electrons makes it possible to carry out calculations S appropriate for experimental results in a wide range of particle energies E0.

AbstractA review on extending the fields of applications of the atomic-force-microscope hybrid mode is presented. This is the main mode for two-probe AFM manipulators. Various methods for improving the feedback system of AFMs, which significantly reduce noise in topographic mapping are presented. Additionally, the successful application of a wide range of probes, both flexible ones such as standard W probes and glass capillaries as well as rigid probes (sapphire probes with probe-tip diameters of dozens of microns) are presented as well. We show examples of the application of this mode in measurements of the conductivity and adhesion forces of nanowhiskers on a Si substrate. Besides this, the application of the hybrid mode in microfluidics and nanofluidics, such as the formation of drops of defined volumes, the replacement of drops, and their division and merging are presented. Examples of different techniques for manipulating nanowhiskers on the surface of a Si substrate are presented. The possibility of the manipulation of nanowhiskers by means of a liquid flow formed by an AFM probe, i.e., avoiding direct tip-to-nanowhisker contact, is shown.

AbstractThe article presents the results of a study of vacuum-arc coatings obtained by the sputtering of Ti–B–Si–Ni cathodes fabricated using self-propagating high-temperature synthesis with simultaneous pressing. The techniques for manufacturing cathodes of the indicated composition are characterized; the modernized HNV 6.6-I1 installation, the conditions and modes of coating deposition in an argon atmosphere and in a nitrogen + argon gas mixture in the ratio of 90/10 are described. To study the physical and mechanical properties of the resulting coatings, the hardness is measured at different loads on the indenter; the strength of adhesion to the base is assessed by the Rockwell method; the elemental composition of the cathodes and the (Ti–B–Si–Ni)N coating is determined using Auger spectroscopy, and the phase composition of the (Ti–B–Si–Ni)N coating is determined using X-ray phase analysis; a study of the properties of the coating (Ti–B–Si–Ni) is carried out by scratch testing. As a result of a comprehensive analysis of the results obtained, it is concluded that the high hardness of the (Ti–B–Si–Ni)N coating (more than 40 GPa) is due to its composition, which includes both nitrides and high-hardness titanium borides. The heterophase nature of the structure of this coating can serve as a contribution to the stressed state of the material. The coating has a graded-layer structure. The material contains a Ti–B–Si–Ni layer bound to the substrate and the main functional layer (Ti–B–Si–Ni)N. The coating has both a high hardness and sufficient strength of adhesion to the base (adhesion) determined by scratch testing. The combination of these properties makes the material promising for its practical application in the production of tools.

AbstractThe effect of a high-power ion beam of nanosecond duration on the stress-strain state of the surface layer of aluminum and its alloys is studied. The data of elemental and phase analysis, residual stresses, sizes of coherent-scattering regions and dislocation density are compared with the microhardness value for different irradiation regimes. A decrease in the lattice parameters of the α phase of aluminum with an increase in the ion current density is found, which indicates the deforming effect of the resulting compressive residual stresses during irradiation with a high-power ion beam. Analysis of the sizes of the coherent-scattering regions in alloys compared with pure aluminum shows a tendency toward their decrease; in D16 alloy grinding occurs by a factor of 1.5, the dislocation density increases by a factor of two, and in V95T alloy, the dislocation density increases by a factor of 3. This trend indicates the significant influence of alloying elements on the dispersion and density of dislocations with varying irradiation parameters.