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Vol 11, No 5 (2017)

Article

Small-angle neutron scattering at fractal objects

Iashina E.G., Grigoriev S.V.

Abstract

The calculation of the correlation function of an isotropic fractal particle with the finite size ξ and the dimension D is presented. It is shown that the correlation function γ(r) of volume and surface fractals is described by a generalized expression and is proportional to the Macdonald function (D–3)/2 of the second order multiplied by the power function r(D–3)/2. For volume and surface fractals, the asymptotics of the correlation function at the limit r/ξ < 1 coincides with the corresponding correlation functions of unlimited fractals. The one-dimensional correlation function G(z), which, for an isotropic fractal particle, is described by an analogous expression with a shift of the index of the Macdonald function and the exponent of the power function by 1/2, is measured using spin-echo small-angle neutron scattering. The boundary case of the transition from a volume to a surface fractal corresponding to the cubic dependence of the neutron scattering cross section Q−3 leads to an exact analytical expression for the one-dimensional correlation function G(z) = exp(−z/ξ), and the asymptotics of the correlation function in the range of fractal behavior for r/ξ < 1 is proportional to ln(ξ/r). This corresponds to a special type of self-similarity with the additive law of scaling rather than the multiplicative one, as in the case of a volume fractal.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):897-907
pages 897-907 views

Mössbauer study of products from the arc synthesis of Fe-carbon nanoclusters

Kozlov V.S., Semenov V.G., Panchuk V.V.

Abstract

This paper presents the results of research into the phase and magnetic state of products of the arc synthesis of Fe-carbon nanoclusters by Mössbauer spectroscopy. These nanoclusters are prepared by the burning of iron-graphite electrodes and carbon-condensate extraction in organic solvents of varying polarity. The local inhomogeneity of the distribution of iron atoms is revealed in the studied samples. It is found that iron atoms are distributed between four iron-containing phases: α-Fe, γ-Fe, FeCn and iron carbide FeC2 at different ratios with an accuracy to the resonant absorption factor f. It is shown that the singlet line with a negative chemical shift observed in the Mössbauer spectra of the samples corresponds to the γ-Fe phase and not to iron metallofullerene.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):908-911
pages 908-911 views

Investigation of the radiation-protective properties of a highly filled liquid glass material

Vilkov F.E., Lozovan A.A., Bazhanov A.V., Kasitsyn A.N., Schekoturova O.E., Solovev M.K.

Abstract

Experimental studies of the radiation-protective properties of a highly filled liquid glass composite coating are presented. Investigations are carried out by irradiating test samples of aluminum alloys with a protective coating applied to their surface. The appreciable attenuation of ionizing radiation by the coating under study up to energies of 150 keV is found.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):912-916
pages 912-916 views

Features of changes in the surface structure of K-208 glass under electron—proton irradiation

Khasanshin R.H., Novikov L.S., Korovin S.B.

Abstract

Changes in the surface structure of K-208 glass after single-time irradiation of its samples with 20-keV electrons and protons are studied using atomic-force microscopy. Irradiation is performed in a vacuum chamber under a pressure of 10–4 Pa; the densities of the electron (ϕe) and proton (ϕр) fluxes are varied in the range of 1010–2.5 × 1011 cm−2 s−1. Analysis of the samples irradiated in the case where the parameters ϕe and ϕр increased in a stepwise manner makes it possible to study the appearance, growth, and evolution of microscopic structures on their surfaces. The radiation-stimulated processes of defect annealing and the release and field diffusion of alkali metal ions are accompanied by crystallization of the irradiated glass layer, which gives grounds for the use of dislocation mechanisms for mass transfer in explaining the formation of microprotrusions on its surface. It is shown that the character of changes in the structure is determined by the values of the parameters ϕe and ϕр and the ratio between them. In particular, it is established that, in the case of electron— proton irradiation of the glass, electrostatic discharges begin to noticeably affect the formation of microprotrusions for ϕе > 3ϕр.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):917-923
pages 917-923 views

Radiation resistance of 4H-SiC Schottky diodes under irradiation with 0.9-MeV electrons

Lebedev A.A., Davydovskaya K.S., Strelchuk A.M., Kozlovski V.V.

Abstract

Degradation of the parameters of 4H-SiC Schottky diodes after irradiation with 0.9-MeV electrons is studied. A charge-carrier removal rate of 0.07–0.09 cm–1 is determined. The Schottky diodes under investigation are shown to retain rectifying current-voltage characteristics up to doses of ~1017 cm–2. The radiation resistance of SiC Schottky diodes is found to be much greater than that of Si p–i–n-diodes with the same breakdown voltage.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):924-926
pages 924-926 views

Study of the combined carbonization of poly(vinylidene fluoride) by X-Ray photoelectron spectroscopy

Zhivulin V.E., Moskvina N.A., Gribov I.V., Andreychuk V.P., Morilova V.M., Khabibullina R.V., Pesin L.A.

Abstract

The surface composition of two samples synthesized by the combined carbonization of poly(vinylidene fluoride) (PVDF) films is studied by X-ray photoelectron spectroscopy. One of them is successively exposed only to chemical and radiation impacts, and the treatment of the other includes chemical, heat, and radiation exposure. The chemical preparation of both samples is the same. It is shown that the magnitude and direction of the gradient of the residual fluorine concentration in the surface layer of PVDF carbonization products can be controlled. Since dehydrofluorination decreases the surface electrical resistance of the material, a combination of chemical, heat, and radiation treatments can be used to create a predetermined sequence of heterolayers with different fluorine concentration on a flexible and transparent polymer base and, therefore, with different conductivities.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):927-932
pages 927-932 views

Structural phase states and properties of the layer surfaced on low-carbon steel with Fe‒C‒Cr‒Nb‒W powder-core wire followed by electron-beam processing

Ivanov Y.F., Kormyshev V.E., Gromov V.E., Konovalov S.V., Teresov A.D., Semin A.P.

Abstract

Structural phase states and tribological properties of the coating surfaced onto Hardox 450 martensite low-carbon steel with powder wire Fe‒C‒Cr‒Nb‒W and modified by subsequent electron-beam processing are studied by methods of modern physical material science. It is shown that irradiation of ~5 thick surfaced layer with high intensity pulsed electron beams results in the formation of ~20 μm thick surface layer with the master phases of α-Fe and NbC, Fe3C and M6C(Fe3W3C) carbides. The main difference of the surface layer modified with electron-beam processing from the unmodified volume of the surfacing is the morphology and dimensions of the second phase inclusions. In the modified layer of the surfacing the inclusions have smaller dimensions and are located in the form of interlayers along the grain boundaries. In unmodified surfacing the particles of the faceted shape located chaotically in the grain volume are the basic morphological type of the inclusions. It is noted that the small value of crystal lattice Nb parameter observed in the experiment may be caused by the high level of vacant interstitial sites having the smaller size in comparison with the occupied interstitial sites. It is established that wear resistance of the surfaced layer after electron-beam processing increases more than 70-fold relative to wear resistance of Hardox 450 steel and friction coefficient decreases significantly (~3-fold).

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):933-939
pages 933-939 views

Polyaniline-Containing composites based on highly porous carbon cloth for flexible supercapacitor electrodes

Klimont A.A., Stakhanova S.V., Semushin K.A., Astakhov M.V., Kalashnik A.T., Galimzyanov R.R., Krechetov I.S., Kundu M.

Abstract

Composites based on commercially available carbon cloth Busofit T-040 and conductive polymer polyaniline are fabricated using the electrochemical polymerization of aniline on the surface of carbon-cloth fibers. The sequence of technological operations for obtaining the composite is optimized; the procedure of preliminary modification of the carbon-cloth surface by electrochemical etching is worked out; and the capacitive characteristics of the obtained composites for use as flexible supercapacitor electrodes are studied. It is found that the introduction of polyaniline into the composition of composite electrode structures leads to an increase in the capacitance by 2–2.5 times compared to the initial carbon cloth due to the pseudocapacitance of polyaniline while maintaining a high electrical conductivity and efficiency. For a composite based on etched carbon cloth, the specific capacitance is 267 F/g (8.9 F/cm2 per unit of the geometric surface of the electrode) with a charge efficiency of 97–99%. The specific surface area of the composite, determined by the BET method, is 548 m2/g.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):940-947
pages 940-947 views

Effect of gamma radiation on the surface and bulk properties of poly(tetrafluoroethylene)

Obvintsev A.Y., Sadovskaya N.V., Khatipov S.A., Buznik V.M.

Abstract

The effect of gamma radiation on the contact angle θ, the work of adhesion γSL for polar and nonpolar liquids, disperse and polar components of the surface energy γS, the magnitude of bulk dielectric polarization P0, and the dielectric increment Δε for sintered and non-sintered poly(tetrafluoroethylene) (PTFE) of suspension polymerization are studied. Sintered PTFE exhibits anomalously high growth of the studied parameters with an absorbed dose up to 500 kGy: Δε by more than four orders of magnitude, the work of adhesion of the polar liquid \(\gamma _{SL}^{{H_2}O}\) by a factor of 1.5, the polar component of the surface energy γpolS by 20 times. The observed changes are found to be considerably larger than those expected from the viewpoint of the amplification of dipole–dipole and donor–acceptor molecular interactions with the participation of polar groups formed in poly(tetrafluoroethylene) upon irradiation. The similar behavior of Δε, \(\gamma _{SL}^{{H_2}O}\), and γpolS parameters depending on the exposed dose and subsequent annealing of the samples at 150°C is revealed. A unified mechanism for changes in the bulk polarization and surface properties caused by the formation in poly(tetrafluoroethylene) of long-lived electron–hole pairs is suggested.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):948-954
pages 948-954 views

Study of the morphology and structure of porous composites obtained from Na–CMC suspensions with aluminum micro-particles and boehmite nanoparticles

Antonova N.M., Babichev A.P., Berezovsky V.S.

Abstract

It is found that adding boehmite nanoparticles to a sodium–carboxymethyl cellulose suspension with glycerin and aluminum powder allows the formation of films with ordered pores (cells of 1200–600 μm in size). X-ray diffraction and infra-red spectroscopy reveal no changes in the chemical composition of films upon their solidification. The surface porosity of the films is established to be 65%. The developed porous composites are shown to be promising in the fabrication of antifriction coatings.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):955-959
pages 955-959 views

Short-Range order of TlIn1–xSnxTe2 thin films

Alekperov E.S.

Abstract

The formation of the short-range order structure of amorphous nanometer-thick TlIn1–xSnxTe2 films (х = 0.02–0.09) obtained via vacuum deposition onto substrates of fresh KCl and KJ chips and celluloid at a temperature below Т = 213 K is studied by high-energy electron diffraction. Both freshly deposited films and films held in vacuum (10–2 Pa) at room temperature in darkness for several months are studied. The effect of the tin concentration on the interatomic distances, the coordination numbers, and the time of amorphous phase stability of TlIn1–xSnxTe2 films due to a great spread in bond lengths and bond angles is established.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):960-962
pages 960-962 views

Influence of elastic-scattering processes on an X-ray photoelectron spectroscopy signal: Effect of the underlying surface

Kaplya P.S., Afanas’ev V.P.

Abstract

The boundary-value problem for the transfer equation with internal sources and without them is solved using the invariant embedding method. The influence of processes of photoelectron elastic scattering on the energy spectra of photoelectron emission is analyzed. The focus of attention is on the analysis of variations in the intensity and the spectral composition of the ascending flow of the photoelectron emission of a layer when underlying layers with different compositions appear. The physical fundamentals of the influence of elastic scattering on the formation of X-ray photoelectron spectra are demonstrated. The peak intensities for homogeneous Au 4s1/2 and Si 2s1/2 targets are calculated with and without the inclusion of reflection processes. The error appearing as a result of neglecting elastic scattering processes, which transform the descending motion into ascending type, is determined.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):963-968
pages 963-968 views

Anomalous asymmetry of carbon nanopillar growth on both sides of a thin substrate irradiated with a focused electron beam

Zhdanov G.S., Lozhkin M.S., Manukhova A.D.

Abstract

The dynamics of carbon nanopillar growth on both surfaces of amorphous carbon films 40–180 nm thick irradiated with a focused electron beam with an energy of 20 keV is studied. Prolonged irradiation causes the retardation and even complete termination of nanopillar growth on the upper side of the substrate while growth on the lower side continues. This unexpected result is explained by the dissociation of precursor molecules diffusing along the substrate by secondary electrons emitted from the conical nanopillar tip. The substrate acts as a filter allowing primary electrons to easily pass, but intercepting low energy secondary electrons. The lower efficiency of secondary electrons emitted in the lower half-space may be due to a decrease in the current density within the expanding beam of scattered electrons.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):969-972
pages 969-972 views

Spontaneous polarization of finely disperse dielectrics with surface donor centers

Kharlamov V.F.

Abstract

Spontaneous polarization and polarization in an alternating electric field of finely disperse dielectrics KMnO4, Pb(NO3)2, and CsNO3 after the appearance of current carriers upon the chemisorption of hydrogen are studied. The real part of their dielectric constant becomes negative, and low frequency dispersion of this quantity due to the Lorentz correction is observed. The spontaneous polarization of finely disperse dielectrics and the low frequency dispersion of their dielectric constant are determined by the properties of conduction electrons whose wave functions are limited by the powder grain size. The character of electronic phenomena and energy exchange upon the polarization of finely disperse dielectrics depends on the position of the Fermi level on their surface. An original method of research is applied.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):973-980
pages 973-980 views

On the possibility of using the Galerkin projection method to model the spatial distribution of minority charge carriers generated by an electron probe in a semiconductor

Seregina E.V., Stepovich M.A., Makarenkov A.M., Filippov M.N.

Abstract

In this paper, the results of using the Galerkin projection method to model the spatial distribution of minority charge carriers generated by an electron probe in a semiconductor material are presented. The problem is solved in the cylindrical coordinate system. The sought distribution is found in the form of the partial sum of the double Fourier series using the system of modified Laguerre functions. An order estimate of the residual error corresponding to approximate solution of the steady-state equation of their diffusion is given. The approximate calculated results are compared with the exact solution of the one-dimensional equation.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):981-986
pages 981-986 views

Experimental and simulation investigations of the peculiarities of relativistic electron beam scattering at a small angle of incidence on a thin flat target

Serov A.V., Koltsov A.V., Mamonov I.A.

Abstract

The refraction angles θd of electron beams passing through aluminum and thin flat copper foils and reflection angles θr are measured. A microtron with 7.4 MeV particles is used as a source of electrons. The angle between the particle trajectory and the target surface α is varied in the range 5°–30°. The dependences of the refraction and reflection angles on the α angle and foil thickness δ are measured. A dosimetric film is used to make pictures of cross sections of the electron beam scattered by a thin 50 μm copper foil. Image processing allows the spatial distributions of refracted and reflected particles to be obtained. The processes of relativistic electron scattering at a small angle of incidence on a flat target are simulated by the Monte Carlo method. The results of simulation are compared with experimental data. Particle scattering at a bimetallic target consisting of 200-μm aluminum and 70-μm lead layers are simulated. A dependence of the spatial-energy distributions on the order of metal layers placed along electron trajectories is found.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):987-993
pages 987-993 views

Method for additional purification of the surface of Si(111) single crystal

Risbaev A.S., Khujaniyazov J.B., Bekpulatov I.R., Rakhimov A.M.

Abstract

A method for additional purification of the surface of single crystals of semiconductors is developed, which consists in the preliminary cleaning of samples by thermal heating in combination or without ion etching in ultrahigh vacuum, followed by implantation with low-energy Ba+ ions (or ions of other alkaline elements) and their successive removal by brief (1 min) high-temperature (T = 1550 K) thermal heating. The effect of additional purification is achieved by the fact that the embedded ions of Ba+ or other alkaline elements, being active, form compounds with impurity atoms (O, C, S, N, etc.) and are removed during hightemperature heating.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):994-999
pages 994-999 views

Neutron-beam former for the REVERANS reflectometer with a vertical scattering plane

Schebetov A.F., Gordeev G.P., Lazebnik I.M., Konik P.I., Didenko G.P., Zabenkin V.N., Axelrod L.A.

Abstract

A device that forms a vertically diverging neutron beam is described. The device allows scanning at the angle of incidence of neutrons on a fluid surface in a reflectometer with a vertical scattering plane. Computer simulation of the former is carried out, and the beam characteristics (horizontal and vertical divergences and the neutron energy spectrum) are obtained. These characteristics are compared with experimental data. Three units are the main advantages of the former: specially fabricated input and output collimators and neutron filters. The reasons for differences in the experimental and simulated data are discussed.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):1000-1007
pages 1000-1007 views

Power loss to generating ion current in radio-frequency ion thrusters and technological sources of ions

Abgaryan V.K., Riaby V.A., Yamashev G.G.

Abstract

The balance of power in a radio-frequency ion source is constructed by calculating the inevitable power loss at surfaces bordering the inductive discharge plasma and power loss to the generation and preliminary acceleration of working-gas ions. The relationship between the specific radio-frequency power consumption per ion-current unit emerging from the source and electron temperature and geometric parameters of the gas discharge chamber is determined.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):1008-1013
pages 1008-1013 views

Evolution of surface morphology during the growth of amorphous and polycrystalline silicon films

Novak A.V., Novak V.R., Smirnov D.I.

Abstract

The evolution of the surface morphology of LPCVD poly-Si films (deposition temperature 620°C), a-Si films (deposition temperature 550°C) and poly-Si films, obtained by the crystallization of a-Si is investigated in the thickness range 40–500 nm. It is found that upon an increase in the thickness from 40 to 500 nm, the surface roughness (parameters Sq, Sz, Sv) is increased for poly-Si, while in the case of a-Si and poly-Si obtained by crystallization a-Si, on the contrary, decreases. The correlation length (Sal) increases for all three types of silicon films. Poly-Si films, obtained by the crystallization of a-Si, as compared to LPCVD poly-Si films have a significantly lower surface roughness, respectively, Sq two times less at a thickness of 40 nm and sixteen times less at 500 nm. In contrast to thick films, thin a-Si films (at thicknesses of less than 40 nm) have a granular structure, which is especially pronounced at an average thickness of about 20 nm and there is a maximum on the dependence of the roughness Sq on the thickness.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):1014-1021
pages 1014-1021 views

Analysis of the surface morphology, structure and properties of polyamidoimide nanocomposites with tubular hydrosilicates

Gubanova G.N., Sukhanova T.E., Vylegzhanina M.E., Lavrentiev V.K., Romashkova K.A., Kutin A.A., Maslennikova T.P., Kononova S.V.

Abstract

The surface morphology, structure and transport properties of polyamidoimide (PAI) films prepared from poly(diphenyloxidiamido-N-phenylphtalimidene) synthesized by low temperature polycondensation, and composites with chrysotile-type hydrosilicate nanotubes (NTs) based on it are investigated using АFМ (atomic force microscopy), X-ray diffraction analysis and pervaporation methods. The dependence of the free surface morphology of PAI films on their thicknesses is found: the minimal value of the roughness parameters is achieved at a film thickness of 15 μm, in this case the minimal value of the sizes of macromolecular “nodules” is also recorded, which is 50 nm. It is established that upon the introduction of NTs up to 7 wt % into PAI films with a thickness of 35 μm, the mesomorphic polymer structure is retained. An antibatic dependence of the nanocomposite transport characteristics on surface roughness parameters is detected. The maximal value of the ideal separation factor for a methanol-cyclohexane mixture is demonstrated to correspond to a composite containing 1 wt % of NTs and possessing minimal values of the surface-roughness parameters.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):1022-1032
pages 1022-1032 views

Profile, morphology and surface elemental composition of through micro-holes in silicon wafers

Zhukov A.A., Zabotin Y.M., Podgorodetsky S.G., Anurov A.E.

Abstract

The micro-profile, elemental composition, and positive etching wedge formed during the Bosch process of through micro-holes in silicon wafers are investigated by methods of optical and scanning electron microscopy, energy dispersive spectroscopy and optical profilometry. The maximum height of the wall profiles is shown to be 3.1 μm at a base length of 100 μm. The dynamics of the positive etching wedge forming on the boundary silicon–polyimide is studied. The most intense etching occurs at the micro-hole center; the wedge’s geometric dimensions (the depth, external diameter and tilt angle) linearly increase in proportion to the number of etching cycles. The elemental composition of the micro-hole surfaces after their formation and also after additional processing is experimentally investigated. It is shown that the sequential removal of polyimide from oxygen plasma and aluminum in liquid etchant does not lead to micro-hole surface contamination.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):1033-1038
pages 1033-1038 views

TEM Study of the microstructure of melt grown FeGe2 single crystals

Bunkin A.Y., Kolosov V.Y., Papushina T.I.

Abstract

The results of transmission electron microscopy and metallographic investigation of the microstructure of FeGe2 single crystals are reported. The main defects revealed are edge dislocations, dislocation loops, and stacking faults located predominantly in close-packed crystallographic planes. The spatial distribution of structural defects is shown to correlate with the specific features of the growth technology. The dislocation density in the samples studied is about 104 cm–2 and is almost constant in a wide pulling-rate range. Small amounts of doping elements (Co, Al, Sn) do not significantly change the microstructure, and thus high quality crystals can be obtained after corresponding correction of the growth parameters.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):1039-1041
pages 1039-1041 views

Polytherms of the wetting angles of zinc and Serbian bronze on tungsten–cobalt hard alloys

Elekoeva K.M., Kasumov Y.N., Kutuev R.A., Manukyants A.R., Ponegev M.K., Sozaev V.A., Khastsaev B.D.

Abstract

The temperature dependences of the wetting angles of zinc and Serbian bronze on a WC–Co hard alloy are studied by the sessile drop method. The polytherm of the zinc wetting angles in the temperature range from the melting point to 800°C is approximated by the equation θ = 149–0.01t, while for Serbian bronze, the dependence θ(t) from the melting point to 600°C is nonlinear. Then, a descending branch is observed, which is approximated by the equation θ(t) = 140–0.005t. The nonlinear dependence of θ(t) is consistent with the previously found dependence for the surface tension σ(t).

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):1042-1045
pages 1042-1045 views

Investigation of the local characteristics of amorphous electrical steel

Virus A.A., Kaminskaya T.P., Stepovich M.A., Korovushkin V.V., Shipko M.N., Tikhonov A.I., Popov V.V.

Abstract

The local characteristics of amorphous electrical steel (foil) before and after exposure to weak (10–100 kA/m) low-frequency (10–20 Hz) magnetic-field pulses are studied by atomic force microscopy, scanning electron microscopy, and electron probe microanalysis. The research results show that, at certain magnetic-treatment parameters, the magnetic properties of the material change, while the concentrations of the phases present in it and the surface structure of the foil remain unchanged.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):1046-1049
pages 1046-1049 views

Structure and properties of a low-carbon steel surface modified by electric arc surfacing

Ivanov Y.F., Gromov V.E., Kormyshev V.E., Konovalov S.V., Kapralov E.V.

Abstract

The structural-phase state and the distribution of microhardness over the cross section of single and double coatings deposited onto martensitic Hardox 450 low-carbon steel by alloyed flux-cored wire, are studied using modern physical materials science. It is demonstrated that the microhardness of a double deposited layer 10 mm in thickness exceeds the microhardness of the base metal by more than three times. It is found that the improved mechanical properties of the deposited layer are due to the formation of a submicro- and nanodisperse martensitic structure containing iron borides forming a plate-type eutectic. Plates of iron boride Fe2B are formed in the eutectic in a single deposited layer, and in a double-deposited layer, plates of FeB are formed. The existence of bend extinction contours, indicating the formation of internal stress fields at the interface between the phases of iron borides and α-iron borides, is revealed.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):1050-1055
pages 1050-1055 views

Energy spectrum of electrons transmitted through curved dielectric tubes

Petukhov V.P., Petukhov M.V.

Abstract

The transmission coefficients and the energy spectra of electrons with an energy of 10–20 keV transmitted through curved glass and polyurethane tubes are measured with a cylindrical electrostatic analyzer. The spectra of X-ray excited by these electrons at the tube outlet are also measured. At larger beamdeflection angles, the spectral distribution of electrons at the curved tube outlet expands considerably, and the maxima of the spectral curves shift toward lower energies. The obtained results suggest that electrons propagating within a curved tube lose energy in the process of inelastic collisions with walls. The transmission coefficient, which is determined by measuring the electron current at the tube inlet and at its outlet, depends only slightly on the electron energy (in the studied energy range) and drop by a factor of more than two when the deflection angle is increased from 0° to 90°.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):1056-1061
pages 1056-1061 views

Comparative analysis of methods for measurement of the surface potential of dielectrics charging under electron-beam irradiation in a scanning electron microscope

Rau E.I., Tatarintsev A.A., Kupreenko S.Y., Zaitsev S.V., Podbutsky N.G.

Abstract

A concise critical analysis of possible methods for measuring the suface potentials of dielectric targets under medium-energy electron-beam irradiation in a scanning electron microscope is carried out. The advantages of studying charging kinetics by recording a shift in the entire energy spectrum of emitted electrons are shown. Two new methods of surface-potential estimation are proposed: using the cathodoluminescence signal and the signal of backscattered electrons. It is found that the total energy of electrons reflected from charged dielectric targets is several times greater than the energy of electrons reflected from an uncharged dielectric.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):1062-1068
pages 1062-1068 views

Emission theory of amorphous-material sputtering. Energy dependence of the sputtering coefficient

Pustovit A.N.

Abstract

The applicability conditions for the Boltzmann kinetic equation in describing the sputtering process are analyzed. The application of the kinetic equation for calculation of the sputtering coefficient is questionable because of the small depth of origin of sputtered particles. A physical model of the emission sputtering theory for amorphous materials is proposed. The threshold sputtering energies and energy dependence of the sputtering coefficient for amorphous materials are calculated in the framework of the proposed model for the case of the normal incidence of primary ions in the energy range of 10 to 105 eV. The calculations are in good agreement with the experimental results.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):1069-1077
pages 1069-1077 views

Synergetics of surface sputtering by polyatomic ions

Oksengendler B.L., Maksimov S.E., Nikiforov V.N., Turaev N.Y.

Abstract

The phenomenon of the sputtering of solids under bombardment with molecular ions is considered within the framework of synergetics. The complete sputtering process is divided into three stages with the help of the concept of three successive regimes: the implementation of a dynamic system, the appearance of a statistical system, and the achievement of a completely statistical system. The manifestation of the basic mechanisms is revealed: elastic cascades and mass transfer under the action of shock waves.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):1078-1081
pages 1078-1081 views

Evolution of the stimulated resonance of a channeling electron beam

Ambartsumov V.V., Kalashnikov N.P.

Abstract

The motion of channeled particles in the co-moving coordinate system can be considered as a onedimensional oscillator (in the case of planar channeling) or as a two-dimensional atom (in the case of axial channeling). The transverse motion of channeled particles is characterized by the discrete spectrum; in this case, the probability of occupation of transverse-motion levels depends on the entrance angle of the charged particle with respect to the crystallographic axes of a single crystal. A charged channeled particle passing through a single crystal experiences the periodic action of lattice atoms. If the frequency of the external periodic action of the crystal lattice coincides with that of the transition of the channeled particle from one quantum state of transverse motion to another, then resonance excitation of the channeled particle can occur; it is similar to the excitation of atomic electrons by the periodic field of a monochromatic electromagnetic wave. In this paper, the resonance conditions are discussed and the dependence of the probability of the occupation of transverse-motion levels of channeled particles (electrons) on the single-crystal thickness is analyzed.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):1082-1088
pages 1082-1088 views

Investigation of crystal imperfections with multiple X-Ray interferometers

Drmeyan H.R., Melkonyan A.H., Knyazyan Z.H.

Abstract

A method of investigation of crystal imperfections on the basis of multiple X-Ray interferometers is proposed and tested. Double and triple X-Ray interferometers enable a more complete description of the deformed state of crystals, revealing different interference patterns (segregation lines, fringe shifts, Moiré patterns), and analysis of the formation of their contrast caused by defects in the crystals under investigation. Double and triple three- and four-crystal interferometers are tested; Moiré patterns are obtained. A perfect method of stereometric topography is proposed for detecting defects in single crystals.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):1089-1095
pages 1089-1095 views

On the possibility of applying the bers apparatus to modeling the processes of heat and mass transfer caused by electrons in a planar multilayer medium

Gladyshev Y.A., Kalmanovich V.V., Stepovich M.A.

Abstract

Some possibilities of joint application of the Bers factorial-function apparatus and matrix method to the mathematical modeling of heat and mass transfer processes in a multilayer medium are considered. The possibility of using this method is shown by the example of the diffusion of minority charge carriers generated by a wide electron beam in multilayer semiconductor planar structures. The results of calculations by this method for homogeneous and three-layer semiconductor structures are presented.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):1096-1100
pages 1096-1100 views

HPHT single crystal diamond type IIB growth sector influence on the secondary electron emission phenomenon

Sadovoy V., Blank V., Teteruk D., Terentiev S., Kornilov N.

Abstract

Secondary electron emission (SEE) coefficient correlation with (100) synthetic HPHT-grown single crystal diamonds type IIa and type IIb growth sectors was investigated. SEE coefficient quantitative measurements were carried out for various growth sectors: the highest magnitudes were revealed for (100), (311) and {110} growth sectors, but {111} growth sectors have SEE coefficient 4‒6 times lower in comparison with mentioned above for both investigated crystal types. The SEE coefficient dependence of primary beam energy is non-standard for all growth sectors: SEE coefficient goes up with primary beam energy increasing. These results are very important for diamond microelectronics as various growth sectors utilization considerably changes output characteristics.

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2017;11(5):1101-1107
pages 1101-1107 views