The experimental studies of active plasma source are presented. The plasma was formed by an incomplete discharge on the surface of ferroelectric BaTiO 3 samples. The spectrum of the discharge was received using the optical emission spectroscopy method. The spectrum lines corresponded to the atoms and ions of elements related to the ferroelectric (Ba, Ti, O) and residual gas (N). The intensity of the spectrum lines depended on the discharge current and varied slightly depending on the residual gas in the pressure range of 10 -5 -10 -3 Torr. An increase in the gas pressure results in the slight increase in the electron temperature of excited atoms of the discharge plasma. The ion emission in a plasma source at a negative bias voltage has been studied.

— The optical properties of Al–Si–N nanocomposite coatings deposited by reactive magnetron sputtering on substrates of stainless steel 12H18N10T and zirconium alloy E110 are studied. The absorption and luminescence characteristics are determined by growth defects and also depend on the type of substrate and its treatment with a powerful ion beam. Absorption and luminescence centers are identified with intrinsic defects in c -Al and a -SiN x and their simplest complexes. The effect of hydrogen absorption and 420-keV proton irradiation on the optical properties of the coatings is established. The dose dependences of the optical characteristics indicate the radiation resistance of the coatings. The radiation resistance of the coatings on zirconium alloy is slightly higher due to the stabilizing effect of silicon-containing defects.

The Vavilov–Cherenkov effect is a well-known phenomenon widely used in various fields, including the diagnostics of charged particle beams. The possibility of separating Vavilov–Cherenkov radiation (VCR) and luminescent light is critical for the development of a new generation of optical methods in the diagnostics of low-energy beams. This paper presents the first experimental results on the detection of VCR from an electron beam with an energy of 5.7 MeV passing through diamond and corundum (sapphire) crystals. It is shown that Cherenkov and luminescent light have different glow times for a corundum crystal, while these times are comparable for synthetic diamond. The optical scheme implemented in the experiment, consisting of a filter and a polarizer, also makes it possible to separate Cherenkov and luminescent light. The proposed scheme for detecting VCR will be used to develop a new method for measuring the ion beam energy at the NICA facility (JINR, Dubna, Russia).

The work investigates the spectral transmittance of corundum (Al2O3) crystal plates before and after irradiation by an electron beam. It reveals the fact that even with a significant irradiation time, the spectral transparency of the plates changes slightly. Moreover, it demonstrates that for a wavelengths of similar to 300 nm, the transparency of the sample remains almost stable, while for shorter wavelengths brightening of the corundum plate is obtained. It is concluded that the use of corundum crystals as Cherenkov radiators for detecting of charged particles beams is prospective.

The effect of short-pulsed irradiation with 220 keV carbon ions for fluences of 2.2 x 10(13) - 2.1 x 10(15) cm(-2 )on the optical and electrical properties of titanium nitride films deposited by reactive magnetron sputtering on silicon and steel substrates has been studied. Relationships are obtained between the irradiation conditions and the parameters of interband absorption. A relationship has been established between the concentration of defects before and after irradiation, the degree of overlap of their levels and changes in the optical and electrical properties of the films. Reasons of high radiation resistance of the films are discussed. The optical and electrical properties of the films change during irradiation in two stages. The first stage is related to the annihilation of defects, the second stage is associated with their accumulation. Irradiation of films significantly slows down the rate of oxidation of their surface layers and stabilizes the electrical properties.

The effect of short-pulse irradiation with 200-keV carbon ions on the optical and electrical properties of aluminum-nitride films and Al–Si–N coatings with variable atomic composition deposited by reactive magnetron sputtering on a silicon substrate is investigated. Absorption and luminescence centers are associated with growth and radiation-induced defects in nitrides and their simplest complexes. A change in the properties during irradiation occurs due to the accumulation of radiation defects and their association into complexes. Ion irradiation is accompanied by intense radiation and the thermal annealing of unstable defects. The dose dependences of the coating characteristics indicate their high radiation resistance, which are slightly inferior to coatings on steel substrates. The radiation resistance of the coatings is due to the limiting effect of growth defects on defect formation, the wide band gap of nitrides and the interaction of defects.

In this paper, we study the optical properties of aluminum- and silicon-nitride films and Al–Si–N coatings with variable atomic composition deposited by reactive magnetron sputtering on glass, silicon, and steel substrates. The absorption and luminescence characteristics are determined by the composition of the coatings and microstructure and depend on the physical properties of the substrate. The absorption and luminescence centers are associated with intrinsic defects in the nitrides and their simplest complexes. The relationships between the accumulation of growth defects, their interaction, the type of distribution of localized states, the band gap, and the stability of the optical properties are established. At an increase in the silicon content in the coatings, the degree of static induced disorder increases, and the contribution of the continuous distribution of the defect levels and interband absorption increases. Silicon-containing defects stabilize the optical properties of the coatings.

The article reports on radiation defect formation parameters and radiation resistance of multilayer coatings from thin layers of aluminum and silicon nitrides deposited on sodium-calcium-silicate glass and monocrystalline silicon substrates by reactive magnetron sputtering. The samples were irradiated with helium ions of 28 MeV on a cyclotron and carbon ions 200 keV on an accelerator in the mode of short-pulse implantation. The characteristics of local absorption and luminescence centers before and after irradiation and their probable nature were determined. The optical centers had been identified as point intrinsic defects of a growth and radiation nature. The accumulation of radiation defects in layers of amorphous silicon nitride a-Si3N4 prevailed over the accumulation in crystalline c-AlN layers due to the diffusion of defects in amorphous layers and the formation of secondary defects in them. Changes in optical properties led to the conclusion about the high radiation resistance of the coatings. The main reasons for the resistance of coatings to ion irradiation were the high concentration of growth defects, their strong interaction and the wide band gap of the nitrides. Coatings deposited on silicon substrates had a higher radiation resistance compared to the same coatings deposited on glass substrates.

The effect of high-intensity short-pulsed ion irradiation on the optical properties of multilayer coatings, consisting from thin layers of aluminum and silicon nitrides, deposited by reactive magnetron sputtering on glass, steel and silicon substrates, has been investigated. The larger the thickness of AlN layers, the stronger the effect of growth and radiation defects on multilayer coating properties. When the concentration of growth defects increases and its interaction intensifies, the radiation resistance of coatings grows. In general, the radiation resistance of coatings was due to the wide band gap of their constituent nitrides and the high concentration of strongly interacting growth defects distributed along the inter-crystallite and interlayer boundaries.

The article reports on the irradiation effects of 350 keV helium ions in the continuous mode and 200 keV carbon ions in the mode of short-pulsed implantation with doses of 20 MGy, 200 MGy and 600 MGy on the optical properties of crystalline aluminum nitride films and nanocomposite coatings based on Al-Si-N triple compound deposited by reactive magnetron sputtering onto a steel substrate. The energy and kinetic characteristics of the absorption spectra due to radiation defects and their simplest complexes are determined. Short-pulsed ion implantation is accompanied by intense radiation and thermal annealing of unstable radiation defects, along with their complexes and the formation of thermostable defect complexes. The influence of the interaction between the states of defects with the growth and/or radiation nature localized in the forbidden zone with the depth on the properties is established. Dose dependences of the optical characteristics indicate a high radiation resistance of the coatings. The radiation resistance of the coatings is due to the limiting effect of high concentration of growth defects on the accumulation of radiation defects, the wide band gap of nitrides, and the interaction of defects through the exchange of charge carriers between their levels.

The effect of irradiation by carbon ions in the mode of short-pulsed ion implantation on the optical and electrical characteristics of graphite-like pyrolytic boron nitride was studied. The characteristics of the states of growth defects localized in the band gap change more significantly with an increase in the energy density of the ion beam, which is accompanied by the ordering of the electronic structure of the compound due to radiation - thermal annealing. Absorption spectra indicate the predominant effect of static disorder due to defects. Irradiation forms a defective semiconductor material with a maximum band gap of 3.3-3.45 eV, a current value of 2.65-2.83 eV for direct transitions and 1.1-1.8 eV for indirect transitions, and an absorption edge due to exponentially distributed states of 1.3-2.6 eV and 2.6-3.3 eV defects of different nature. Anion vacancies, their clusters and impurity-vacancy complexes make the main contribution to the material properties. Irradiation forms low - conducting dielectric layers with surface conductivity of mixed n- and p-type on the surface of a pyrolytic boron nitride. The conduction mechanism is determined by the activation exchange of charge carriers between the allowed bands and donor and acceptor levels due to radiation and growth defects. After irradiation, the Fermi level remains localized near the position characteristic of the pyrolytic boron nitride near the middle of the band gap.

This paper presents the results of an experimental investigation on the optical properties of the SixTiyCzOw nanopowders, produced by the pulsed plasma chemical method. Pulsed plasma chemical synthesis is realized on the laboratory stand, including a plasma chemical reactor (6 l) and TEA-500 electron accelerator. The parameters of the electron beam are as follows: 400-450 keV electron energy, 60 ns half-amplitude pulse duration, up to 200 J pulse energy, and 5 cm beam diameter. The spectrum of the diffuse reflection coefficient R(h nu) was measured using the AvaSpec-2048-2 (Avantes) spectrometer with the AvaLight-DHS light source (deuterium and halogen-tungsten lamp) and an integrating sphere. The band gap of the obtained composite is 2.03-3.12 eV.

This paper reports on the effect of the irradiation of Al-Si-N coatings by an intense pulsed ion beam. The Al-Si-N coating was deposited on a steel substrate by a reactive magnetron sputtering. The Al-Si-N coating with a high silicon content (30 at.%) was irradiated by a high-intense pulsed C+ ion beam. It was shown that metastable growth defects (GDs) created in the Al-Si-N coating during deposition can be healed up by its post-deposition irradiation using several pulses (1 and 10) of C+ ions with energy E-i = 200 keV, ion current density i(s) = 7 A/cm(2), pulse duration t(p) = 110 ns and radiation dose 2 MGy. The reduction in deposition-induced GD density results in an increased transmittance of the Al-Si-N coatings.

The characteristics of interband and exponential optical absorption of leucosapphire and polycrystalline corundum (polycor) after irradiation with chromium ions and subsequent annealing in vacuum at 300–1800 K and in air at 300–800 K are studied. Contributions of defects with different thermal and chemical stability into optical parameters were established. The effect of intrinsic radiation defects, of substitutional defects and of complexes on base of oxygen and defects on formation the focal point in absorption spectra owing to fulfilment of the Urbach rule was determined. Heating in air of strongly defective material synthesized in surface layers of alumina by the ion–heat modification influences the characteristics of defects and the electronic structure of band gap negligibly.

This paper presents the results of an experimental investigation on the optical properties of the TiO2 and TixCyOz nanopowders, produced by the pulsed plasma chemical method. Pulsed plasma chemical synthesis is realized on the laboratory stand, including a plasma chemical reactor (6 l) and TEA-500 electron accelerator. The parameters of the electron beam are as follows: 400-450 keV electron energy, 60 ns half-amplitude pulse duration, up to 200 J pulse energy, and 5 cm beam diameter. In TiO2 sample, obtained using the pulsed plasma chemical method, the particles can be divided into two groups: 100-500 nm large spherical particles and tiny complex particles (sized less than 100 nm). For TixCyOz sample, the morphology of the particles is mainly presented with irregular fragment shape. The average size of the particles is ranged from 200 to 300 nm. The band gap for all synthesized samples is within 2.94-3.35 eV.

The paper is focused on the study of the structural, electrical and optical characteristics of the ceramic silicon carbide before and after irradiation in the regimes of the high-power ion beams (HPIB) and high-intensity short-pulse implantation (HISPI) of carbon ions. The dominant mechanism of transport of charge carriers, their type and the energy spectrum of localized states (LS) of defects determining the properties of SiC were established. Electrical and optical characteristics of ceramic before and after irradiation are determined by the biographical and radiation defects whose band gap (BG) energy levels have a continuous energetic distribution. A dominant p-type activation component of conduction with participation of shallow acceptor levels 0.05-0.16 eV is complemented by hopping mechanism of conduction involving the defects LS with a density of 1.2T017-2.4T018 eV-Am-3 distributed near the Fermi level.The effect of radiation defects with deep levels in the BG on properties change dominates after HISPI. A new material with the changed electronic structure and properties is formed in the near surface layer of SiC after the impact of the HPIB.

The optical and electrophysical properties of polycrystalline diamond films (PDF) deposited from the abnormal glow discharge have been studied. The dominating mechanisms of absorption and charge carrier transfer and the energy spectrum of the localized states (LS) of defects which determine the properties of the films have been specified. The parameters of the interband absorption and electrical conductivity are determined by the continuous energy distribution in the band gap (BG) of the states of defects of different nature. The absorption edge of the crystalline phase of the films is separated from the absorption zone determined by the electron transitions between LS defects. The width of BG is narrowed to 0.2-0.5 eV from the quantity typical to the diamond. An additional film absorption edge is formed in the energy interval 1.2-3.3 eV, where Urbach rule is fulfilled and the interband absorption is realized at direct transitions through the optical gap 1.1-1.5 eV. The average width of BG is 2.6-3.24 eV estimated within semiclassical interband model. The interaction of the parameters of the interband and exponential absorption is determined by the crystal lattice static disorder. The dominating n-type of the activation component of the electrical conductivity is complemented by the hopping mechanism with the participation of the localized states of the defects distributed near the Fermi level with a density 5.6T017-2.1·1021 eV-1-cm-3.

The paper is focused on the study of the boron doping effect on the electrical characteristics, on the mechanism of charge carrier transfer, and on the energy spectrum of the localized defect states in the polycrystalline diamond films (PDF) deposited from an abnormal glow discharge. PDF doping enables to form the semiconductor layers of p-type conductivity, which have as good properties as those of PDF produced by the alternative methods. The doping reduces the degree of disorder in the film material brought by the growth defects, which determine the film electrical characteristics and electrotransfer mechanism. The PDF electrical characteristics and electrotransfer mechanism are determined by the defects of different nature, whose band gap energy levels have a continuous energy distribution. A p-type activation component is realized in the exchange of charge carriers between the valence band and shallow acceptor levels with the activation energy of 0.013-0.022 eV. Doping increases the effect of the hopping mechanism of the conductivity involving the localized states with a density of (1-6)·1020 eV-1 •cm-3 distributed near the Fermi level, which is in the low half of the band gap.

Electrical and photoelectric properties of polycrystalline silicon after high-intensity short-pulse implantation of carbon ions have been studied. It has been found that vacuum annealing (10 –2 Pa, 300–1200 K) of silicon affects the surface dark and photoconductivity. Optimal conditions of thermal vacuum treatment of silicon have been found that provide the most heat and field resistant changes in its properties. Probable causes for the changes in electric and photoelectric characteristics of the material have been revealed.