Abstract An expression for the free energy of nucleus formation from liquid phase of a catalyst during growth of III–V semiconductor nanowires (NWs) via the vapor–liquid–solid (VLS) mechanism has been derived with allowance for depletion of the number of atoms of the group V element (As) in the drop as a result of the island growth during As deposition from the gas–vapor phase. Various regimes of island

Abstract The nuclear stopping power of hydrogen and helium isotopes in Be, C, and W materials that are promising for use as the first wall of a tokamak reactor are calculated. It is shown that the presence of an attracting potential well has a substantial effect on the dependence of the nuclear stopping power on the collision energy. The use of potentials calculated in the approximation of the density

Abstract Composite plasmonic structures consisting of gold nanoparticles and carbon nanodots (CDs) in mesoporous silica particles have been synthesized. It has been established that the visible photoluminescence of CDs in these structures is three times more intense than that in analogous structures free of gold nanoparticles.

Abstract Acoustic emission upon mechanical loading of alloys of the Pb–Sn system is studied. It is revealed that the Kaiser effect is not observed under repeated loading of the material at component concentrations leading to the formation of a eutectic structure. An explanation for the absence of acoustic-emission memory in eutectic lead-based alloys is proposed. The explanation is based on the specific

Abstract The effect of UV radiation and a strong electric field on the current–voltage characteristics of resistive structures based on polymorphic gallium oxide (Ga2O3) films is discussed. Ga2O3 films were deposited by the method of halide vapor phase epitaxy (HVPE) on smooth and patterned sapphire substrates with a baseline orientation (0001). α-Ga2O3 films grow on smooth substrates, and gallium

Abstract The spectrum of IR active noncovalent interactions of the eggshell membrane has been studied, and the energies of these interactions are estimated. The obtained results are compared to data reported previously for various samples of human aortic valve tissues. It is concluded that the eggshell membrane offers a promising analog of the basal layer of the aortic valve that can be used for biophysical

Abstract A design of a tunnel junction (TJ) based on n++-InGaAs/p++-InGaAs/p++-InAlGaAs layers for vertical-cavity surface-emission lasers (VCSELs) for the 1.55-μm spectral range fabricated by wafer fusion of an InAlGaAsP/InP optical cavity and wafers with AlGaAs/GaAs distributed Bragg reflectors has been suggested and tested. The presence of the oxidation-resistant InGaAs layers makes it possible

Abstract We calculated the compaction parameters of CoSb3 thermoelectric powders under field-activated sintering. The values of the creep activation energy, sensitivity to the strain rate, and the complex parameter of the material characterizing the state are obtained. The compaction of the powders is due to the mechanisms of grain sliding in the sample. We performed the computer simulation of the

Abstract The effect of modification of a porous carbon material used to manufacture supercapacitors with a polymeric cobalt complex with a Salen-type Schiff base on the capacity of the material has been studied. Conjunction of multielectron redox processes in the polymer with the proposed effective modification technology makes it possible to increase the electrode capacity by 2.4 times in comparison

Abstract The destabilization of a cumulative jet with an initial velocity of more than 8 km/s upon penetration into brittle materials is studied. Using electron microscopy, the state of materials that remain in the cavity is analyzed. The observed phase transformations of copper and brittle materials in the residual cavity indicate high temperatures in the penetration region and reveal the effect of

Abstract Specific features of the current processes in silicon heterojunction with intrinsic thin layer solar cells have been investigated. The proposed model takes into account the ambipolar motion of carriers and allows one to calculate the operating characteristics at an arbitrary ratio of the diffusion length and the crystalline-substrate thickness. A numerical method for estimating the recombination-loss

Abstract The relationship between the spatial parameter of the development of a localized plastic flow (the length of the localized plasticity autowave) and the length of the deformed sample is studied. According to experiments carried out on polycrystalline samples of a zirconium alloy and commercial purity aluminum, these quantities are related to each other by a logarithmic law valid at the stage

Abstract It is shown that laser modification of a nanometer titanium film can be used for precise control of the loss level in optical waveguides on lithium niobate substrates. Theoretical estimates of the change in linear losses at the level of 0.95 dB/mm were confirmed by experiments on local laser modification using radiation at a wavelength of 976 nm with a threshold intensity of 1 kW/mm2. The

Abstract A radioabsorbing structure shielding a metal plane in the form of a ferrite layer with a dielectric layer containing a grating of resistive squares has been considered. The diffraction problem of a plane electromagnetic wave incident perpendicular to the surface of the structure has been solved. Based on the solution of the optimization problem, it is shown that, in contrast to the ferrite

Abstract The method of hot-filament chemical vapor deposition has been employed to synthesize diamond particles with germanium–vacancy and silicon–vacancy color centers. In the next stage, the reactive ion-plasma etching of the particles was performed. This, yielded diamond nanoparticles with photoluminescence spectra constituted by two narrow high-intensity zero-phonon lines of the centers introduced

Abstract Electron-stimulated desorption (ESD) of K atoms from the surface of K/KxAuy/Au/W system has been studied. It is established that the ESD process occurs in the K adlayer and adjacent KxAuy subsurface layer. A model of the ESD of K atoms from the K/KxAuy/Au/W system is proposed. Semiconductor nature of KxAuy compounds is confirmed.

Abstract A variant of the scheme of a magnetometric sensor based on cesium atomic vapor is proposed and experimentally investigated. The sensor uses magnetic resonance excitation by modulated light of an hyperfine optical pumping that is transverse to the magnetic field. It is shown that, for a cell with a volume of 0.125 cm3, the variational sensitivity of such a scheme, estimated from the ratio of

Abstract Single-electron transport in a planar structure of InSb, PbS, and CdSe semiconductor colloidal quantum dots has been studied by scanning tunneling microscopy. Current dips similar to the Coulomb gap have been observed in the I–V characteristics. The qualitative and numerical comparative estimates suggest that a structure consisting of a set of quantum dots exhibits single-electron transport

Abstract This paper investigates the formation mechanism of the propulsive force of a flapping airfoil, which performs harmonic angular oscillations in a continuous medium flow, in the light of the recently proved general theorem on the added mass of bodies in a viscous incompressible fluid. The flow is described by the Navier–Stokes equations. The calculations were performed by the mesh-free numerical

Abstract High strain rate deformation of aged alloys has been theoretically analyzed. Different types of the experimentally observed concentration dependences of the yield stress are explained within a unified approach.

Abstract A numerical study of the gas dynamics of the processes of the outflow of a rarefied binary gas mixture with a large ratio of the species mass from the source into vacuum is carried out. The calculations are performed by the direct simulation Monte Carlo method. The effect of increasing the density of the heavy species in the vicinity of the outlet of the source is revealed . A significant

Abstract An ultra-wideband bandpass filter formed by cascading of a novel high-pass filter (HPF) and a low-pass filter (LPF) on suspended substrates with a two-sided pattern of strip conductor has been investigated. The high selectivity of the HPF is ensured by the transmission zeros near the passband, the number of which is equal to the filter order. A second-order HPF has been designed on a 0.5-mm-thick

Abstract AlGaAs/GaAs microdisk lasers with InAs/InGaAs quantum dots have been transferred to the surface of a silicon wafer using an indium solder. The microlasers have a common electric contact deposited on top of the residual n+-GaAs substrate and individual addressing is ensured by placing the microdisks with the p contact down onto separate contact pads formed on silicon. No effect of a non-native

Abstract— The mechanism of enhancing the interaction of optical radiation with a superconducting niobium nitride film on the surface of optical waveguides on a lithium niobate substrate using an additional cover layer with a high refractive index has been studied. It has been shown that adiabatic deformation of waveguide modes allows increasing the absorption of light in a superconducting film to the

Abstract Quantum capacitance CQ of an infinite graphene sheet, a graphene nanoribbon, and a chain of carbon atoms (carbyne) have been analytically estimated within the framework of simple models. A nonmonotonic dependence of CQ on the electrostatic potential is demonstrated. The data obtained are compared with the calculation results of other researchers.

Abstract The laws of drop formation are experimentally studied in narrow horizontal microchannels with rectangular section with heights from 50 to 150 μm. It is shown that there exists a new flow regime when the drops in the form of vertical liquid bridges move along the microchannel. Three mechanisms of formation of such drops are distinguished: formation directly near the liquid nozzle, departure

Abstract We report an experimental study of the electrical properties of the interface between the Al2O3 passivating coating grown by plasma enhanced atomic layer deposition at different temperatures and the p-CdHgTe (xCdTe = 0.22) coating grown by molecular beam epitaxy via measuring the C–V characteristics of MIS structures. It has been established that, at an Al2O3 growth temperature of 200°C, the

Abstract Results are reported of an experimental study of the scattering and near-field interaction of a terahertz electromagnetic field with graphene ribbons near the metallic probe of an atomic-force microscope. It is shown that the near-field terahertz scattering in ribbons is enhanced in comparison with that in the case of an unstructured graphene. Resonance peaks at 0.2–1.6 THz appear in the spectra

Abstract We have studied the magnetic properties of two-phase borosilicate glasses with matrices containing a mixture of β-Fe2O3 and Fe3O4 nanoparticles. The dimensions of the oxide nanoparticles are determined, and the temperature of blocking (TB ~ 330 K) of the ensemble of superparamagnetic nanoparticles is estimated. It is also established that a sharp increase in the specific magnetization of these

Abstract The behavior of a cylindrical body with a nonaxisymmetric cross section in a horizontally positioned cylindrical cuvette filled with viscous incompressible fluid and performing rotational oscillations is experimentally studied. The effect of vibrational suspension of a heavy nonaxisymmetric cylinder near the bottom of a vibrating cavity at a distance comparable with the thickness of the Stokes

Abstract A powerful pulsed dc converter has been developed for charging battery assemblies on board of hybrid and electric aircraft, which enables full battery capacity charging in cruise mode of the aircraft. This 10-kW modular design converter can operate in a buck–boost mode in a voltage range of 130–300 V with a current limit of 70 A at an output voltage of 150 V. The efficiency of the created

Abstract The results of hardness and Young’s modulus study of near-surface layers of 4H-SiC hexagonal silicon carbide obtained by the modified Lely method from the C-face (000\(\bar {1}\)) and Si-face (0001) at shallow depths of the indenter are presented. It is shown that the differences in the elastic properties and hardness of SiC propagate from the surface into the crystal at a depth of about 60

Abstract The possibility of local measurement of the fluctuation level of the radial plasma velocity using equatorial enhanced scattering of a narrow microwave beam in the upper hybrid resonance in internal regions of tokamak plasma is demonstrated. Restrictions of the proposed method at the plasma periphery where the density fluctuation amplitude increases and small-angle scattering of microwaves

Abstract The results of studies of the dynamics of near-electrode processes in the initial phase of a spark discharge in atmospheric-pressure air in the point-plane geometry are presented. After breakdown, regions of about 50 μm or more in size with an increased electron concentration of (3–8) × 1019 cm–3 near the surface of the flat cathode have been observed. With allowance for the experimental data

Abstract The propagation time of chaotic ultra-wide-band rf pulses through a wireless multipath-propagation channel in the frequency range from 3 to 5 GHz has been experimentally determined. The error in measuring the propagation time of chaotic ultra-wide-band rf pulses has been estimated from their envelope for the solution of the problem of measuring the distance between objects and their localization

Abstract A titanium surface has been irradiated by a femtosecond laser in n-hexane at different pressures. The influence of laser-induced plasma on the character of formation of the surface-periodic structures in the pressure range from 6 mbar to 22 bar has been considered. The surface of the treated samples is analyzed by scanning electron microscopy. It is shown that the period of the obtained laser-induced

Abstract The morphology, composition, and electronic properties of CoSiO films formed on a CoSi2/Si(111) substrate surface by \({\text{O}}_{2}^{ + }\) ion implantation followed by thermal annealing have been studied. Energy band structure parameters are determined, and information on the density of electron states in the valence and conduction bands is obtained. The bandgap width of a CoSiO film is

Abstract The peculiarities of the process of preparation of metal oxide nanopowders by the evaporation–condensation method with pulsed heating of the material by focused subterahertz radiation are described. It is shown experimentally that the optimal conditions for the rapid evaporation of a substance are achieved at the highest possible pulse power and the largest possible duty cycle at a fixed average

Abstract Scanning electron microscopy and X-ray spectroscopy have been used to study the effect of processing of multiwalled carbon nanotubes (MWCNTs) with an argon ion beam on the structure of SnOx/MWCNT composites formed by magnetron sputtering. It has been shown that the use of ion processing increases the interfacial adhesion and allows forming composites with a uniform distribution of tin oxide

AbstractFor the conditions obtained in experiments on the interaction between a shock wave and the ionization-unstable plasma, the influence of a thermally stratified energy source on the front of a shock wave is numerically modeled on the basis of the full system of Navier–Stokes equations. It is shown that the front curvature detected in schlieren images is associated with a higher temperature of

AbstractPhotoelectric characteristics of photodetectors of the type of a photoresistor based on microcrystalline films of the organometallic perovskite CH3NH3PbI3 with gold and aluminum contacts have been studied. The maximum photosensitivity of the photodetectors was 30 A/W. The buildup and decay times of the photoconductivity were in the range from 2.6 to 25.5 μs.

Abstract—The possibility and efficiency of laser excitation of the elastic vibrations in microoptoelectromechanical systems under the action of recoil force upon an external photoeffect have been analyzed. It has been shown that this mechanism of vibration excitation can be an order of magnitude more effective than the light pressure in these systems based on GaAs. The proposed method of creating such

AbstractThe dependence of the temperatures of magnetic phase transformations in porous ferromagnetic materials on the geometric characteristics (volume and shape) of pores and their distribution in a particular material has been studied. The geometric features of nanopores have been characterized by their effective pore radius and form factor (deviation of the pore shape from spherical). Estimations

AbstractA method and calculation results are presented for the flow field and convective heat transfer in a hollow cylinder having an end wall and rotating about the axis of symmetry under variation of the angular velocity of rotation and cylinder height.

AbstractResults are presented of a study of the morphology of germanium films nanostructured by ion implantation. Film samples were grown by magnetron sputtering in an ultrahigh-vacuum installation and then irradiated with 40 keV Ge+ ions at fluences in the range of (1.8–8) × 1016 ions/cm2. Scanning electron microscopy demonstrated that vacancy complexes with diameters of ~50–150 nm are gradually formed

AbstractUsing the method of DC magnetron sputtering, nonstructured amorphous metal coatings of Zr75Pd25 composition were obtained with an average deposition rate of 1.3 nm/s at a substrate temperature of 40°C, while crystalline coatings were formed at a higher substrate temperature. A crystalline coating with equilibrium phase composition was obtained at 350°C. Coatings deposited at intermediate temperatures

AbstractWe proposed a model of neural dynamics based on a phase-locked loop system with delayed feedback. The model can demonstrate chaotic oscillation modes, in which switching between qualitatively different types of oscillations that are characteristic of neural activity takes place.

AbstractThe feasibility of detecting the emission of a microdisk laser with a diameter of 23 μm with an active region based on InGaAs/GaAs quantum well-dots using a nearby photodetector (100 × 4000 μm) with a similar active region is demonstrated. For continuous lasing, a pump current of 20 mA, and a distance between the faces of the microlaser and the photodetector of about 100 μm, a photocurrent

AbstractWe used field emission microscopy to study the field desorption of sodium and cesium atoms from a rhenium field emitter precarbonized in benzene vapor. The dependences of the ion currents of sodium and cesium on the voltage applied to the field emitter differ. The difference in the ion current dependences is explained by the formation of multilayer graphene on the crystalline surface of a rhenium

AbstractThe deformation behavior of 3D 03X17H14M2 steel samples with various lattice structures created by selective laser melting has been studied under compression conditions using the digital image correlation method. Spatially temporal patterns of localization of transverse (εxx) and longitudinal (εyy) deformations of topological structure actual types have been studied. It has been found that

AbstractThe possibility of using a diluted magnetic semiconductor (In, Fe)Sb as a functional layer for use in spintronics, namely, as a ferromagnetic injector in a spin light emitting diode, has been investigated. The luminescent characteristics, as well as the temperature dependence of the circular polarization degree of of a spin LED electroluminescence with an (In, Fe)Sb injector, are studied.

AbstractAn analytical method for determining the amplitude and velocity of an autowave pulse emerging in isentropically unstable heat-releasing media is presented. The method is suitable for any values of acoustic dispersion and growth rate and requires the knowledge of heat-loss function only without the need for a numerical solution of a complete system of gas-dynamic equations.

AbstractThe paper presents the calculations of the physical and energy parameters of nanocarbon structures with the components of a metal-porous cathode active substance. Obtained results match experimental data. It has been experimentally determined that the active substance modified by the sulfoadduct of carbon nanoclusters has an evaporation rate 1.5 times lower than the typical one. Tests of nanocarbon-modified

AbstractThe results of growing multilayered nitrogen-doped nanostructures that have the form of periodically arranged nanometer-thick nitrogen-containing layers in a single-crystal CVD diamond are presented. The possibility of creating nitrogen-doped diamond layers with extremely sharp boundaries (less than 1 nm) is demonstrated. The photoluminescence study have shown that multilayered structures make

AbstractHigh-efficiency concentrator photovoltaic modules have been developed and fabricated. The modules include a lens panel based on 32 Fresnel lenses (12 × 12 cm each), 32 multi-junction solar cells with secondary concentrators in the form of phocons, and heat-removing electrically insulating boards based on an aluminum oxide ceramic placed on the backside aluminum base. Efficiency measurements

AbstractThe influence of thermomechanical cycles (compression along the [011] direction and recovery of the shape memory strain upon crystal heating) on the form and characteristics of the compression diagrams of Ni49Fe18Ga27Co6 alloy crystals not subjected to high-temperature annealing and quenching in water after the growth has been investigated. It is found that these characteristics change during

AbstractThe possibility of organizing multiuser access based on the differentially coherent information transmission scheme using chaotic radio pulses as data carriers has been demonstrated. Some theoretical estimates were made for the maximum number of subscribers and the information capacity of a multiuser system. Computer-aided modeling was performed to validate the obtained theoretical results

AbstractCondensation and adsorption of Ni with a thickness from several tenths of a monoatomic layer to several hundred layers on the surface of a single-crystal W tip has been studied by field emission microscopy in a wide range of surface temperature T. In contrast to adsorption of Si on W, adsorption of Ni on W does not induce any W surface reconstruction in the entire range of substrate temperatures

AbstractThe electrical injection of the spin-polarized current into silicon in the Fe3Si/n-Si epitaxial structure is demonstrated. The spin accumulation effect is examined by measuring the local and nonlocal voltage in a special four-terminal device. The observed effect of the electric bias on the spin signal is discussed and compared with the results obtained for ferromagnet/semiconductor structures