Vol 43, No 6 (2017)

The results of examination of thin-film samples of the LiPON solid electrolyte, which were synthesized by magnetron sputtering, are reported. Data on the morphology, structure, elemental and phase composition, and electrophysical parameters of LiPON films are presented.

The distribution of charge particles in glow-discharge plasma during shock wave propagation through it is measured by a double electric probe. It is established that a decrease in the ion concentration in front of the shock wave is related to the occurrence of ion-acoustic oscillations in the plasma.

The influence of the heating rate of a solid solution up to the temperature of isothermal annealing on the distribution of CuCl particles by radii has been studied using the example of a solid solution of CuCl in glass. The study of changes in the distribution of particle radii in the CuCl phase has been performed using exciton-thermal analysis. It has been found that, with slow (60 min) heating of the sample to 650°C, the concentration of nucleates in the CuCl phase first increases rapidly and, then, the concentration decreases. The decrease in concentration is explained by the rapid growth of the critical radius with temperature and depletion of the solution. As follows from numerical simulation, the nucleation in a solution of CuCl in glass under conditions of slow heating is in good agreement with the experimental data.

The diffusion pumping of graphene by optical plasmons, propagating in metal, and separated from the graphene by a semiconductor layer has been investigated theoretically. It is shown that pumping of graphene with optical plasmons provides maximum negative terahertz conductivity of graphene at a lower (approximately by 25%) pumping power compared to a diffusion pumping of graphene with optical radiation.

Thin tin oxide films were fabricated by reactive RF magnetron sputtering. It was shown that the films possess gas sensitivity to ethanol vapor at 38°C. Measurements of the morphology and cleavage inner structure of the samples by atomic-force and scanning electron microscopy demonstrate that the films are composed of nanodimensional rod-like grains oriented normally to the substrate. The grains are separated by pores piercing the whole film. It was found that the grain diameter distribution is normal logarithmic one with several centers related as small integers, which indicates that the grains coalesce. The minimum grain size of 6 nm might correspond to the critical nucleus size under the used conditions of film deposition.

To solve the problem of the evaluation of the characteristic sizes and patterns of surface microdefects of complex-shaped samples, a holographic method for the measurement of transparent replicas representing an inverse impression of the investigated surface is proposed. This measurement method is based on the digital registration of the interferograms of a polymeric replica in the modified off-axis Leith–Upatnieks holographic scheme and on the calculation of the phase-incursion difference from a series of reconstructed digital holograms.

A mass spectrometer with a membrane interface has been used for measuring the relative concentration of carbon dioxide (CO₂) released from rat skin in response to thermal irritation and pain stimulus during intraperitoneal propofol–lidocaine anesthesia. It is established that the local anesthetic lidocaine directly influences the central nervous system and induces antinociceptive reaction to thermal irritation.

Results of gasdynamic and spectroscopic investigations of optical discharge in the subsupersonic flow of a homogeneous fuel–air (CH₄ + air) mixtures are presented. The combustion was initiated and maintained by optical discharge created using a CO₂ laser. The laser radiation propagated across the flow and was focused by a lens on the axis of the supersonic jet (M = 2). Emission-spectroscopy techniques provided data on the composition of radiating combustion products and the intensity of components emitted in the region of optical discharge. Patterns of Toepler’s visualization of the flow structure in the schlieren scheme are presented. The images were monitored by a high-speed video camera operating at an exposure time of 1.5 μs and a frame frequency of 1000 s^–1.

We have experimentally studied the formation of a droplet cloud during intense heating and subsequent explosive fragmentation of an inhomogeneous liquid drop. The experiments were performed with water drops containing graphite particles, which were heated in a flow of combustion products at a temperature varied from 600 to 1100 K. Three regimes of fragmentation of the inhomogeneous liquid drops have been observed, which are characterized by different total areas of liquid phase surface in aerosol clouds. Dependence of these regimes on the water/inclusion volume ratio and the amount of supplied heat has been determined.

A new method of introducing carbon into catalytic metal films for graphene synthesis is proposed. The method is based on the phenomenon of carbon recoil atoms from a layer of methane molecules that are adsorbed on a metal film being incorporated into this film under the action of bombardment with inert gas ions. To increase the thickness of adsorbed methane layer, the substrate is cooled down to −190°C. The proposed method has been implemented on a polycrystalline nickel film. After the final annealing, Raman spectroscopy showed the presence of numerous fragments of multilayer graphene on the film surface.

Vibrating-sample magnetometry techniques has been used for investigation of the electrophysical characteristics of several types of modern commercial multistrand composite wires based on Nb₃Sn superconducting compound at temperatures that were measured 4.2, 7, and 12 K in magnetic fields up to 8 T before and after irradiation of the samples by fast (32-MeV) protons to fluences values 3 × 10¹⁶, 1 × 10¹⁷, 3 × 10¹⁷, and 1 × 10¹⁸ cm^–2. All samples irradiated to fluences values up to 1 × 10¹⁷ cm^–2 exhibited growth of the critical current density, which was most sharply pronounced in strong magnetic fields at lower temperatures. Further irradiation to a fluence value of 1 × 10¹⁸ cm^–2 led to decrease of the critical current density below the initial level. The critical temperature of samples monotonically decreased with increasing irradiation dose.

Current–voltage (I–V) characteristics of Au/Ti/n-InAlAs/InP Shottky barriers have been studied in a temperature range of 100–380 K. It is established that, as the temperature increases from 100 to 200 K, the ideality factor drops from 1.58 to 1.1, while the barrier height grows from 0.55 to 0.69 eV. With a subsequent temperature increase from 200 to 380 K, both the ideality factor and barrier height vary, but only weakly. This behavior agrees well with the model of lateral inhomogeneity of the barrier height (Tung model), which is confirmed by the linear dependence of the barrier height on the ideality factor at temperatures within 100–200 K. Calculations according to this model yielded the value of 0.88 eV for the homogeneous-junction barrier height, 10^–4 cm^2/3 V^1/3 for the mean-square deviation of the Gaussian distribution of barrier heights, 3.7 × 10^–11 cm² for the effective area of regions with reduced barrier heights, and 10.7 A cm^–2 K^–2 for the Richardson constant.

A special approach to calculation of the spectrum of Lyapunov exponents has been developed and applied to diagnostics of the degree of regularity of wave structures in a model neural system. A transition between the regimes of regular wave dynamics and developed spatiotemporal chaos is demonstrated and quantitatively characterized.