Abstract New Al/SiC heteroparticles are investigated experimentally and theoretically. A composite material based on Al and SiC is predicted to exhibit a markedly higher tensile strength than pure Al due to the robust interface between Al and SiC. The theoretical predictions receive experimental confirmation. Specifically, incorporation of nano-SiC into the aluminum matrix to a level of 10 wt % is

Abstract The role of clustered particles in the formation of a secondary flow (“wake”) upon the outflow of gas into a rarefied medium in condensation modes is found out. The boundaries of the “wake” are found by comparing the spectral and photometric measurements. Possible mechanisms of the initiation of its glow are considered. The role of the energy exchange of clusters with background gas in the

Abstract AlN/c-sapphire templates grown by plasma-activated molecular beam epitaxy have been studied using multicrystal X-ray diffractometry and a multi-beam optical stress meter system. Studies of the seed and buffer layers grown at different ratios of Al and N* growth flows and substrate temperatures have shown that templates with small tensile elastic stresses (<0.5 GPa) and densities of screw and

Abstract The kinetics of nucleus growth from a parent nanophase medium with a limited stock of material has been theoretically studied in the presence of possible growth arrest caused by destruction of the source of supersaturation. This regime is characteristic of the island growth of GaAs nanowires (NWs) from a Ga nanodroplet via the vapor–liquid–solid (VLS) mechanism as observed during in situ diagnostics

Abstract A new miniature design of a highly selective lowpass filter based on a suspended substrate with a two-sided stripline pattern has been developed. The filter frequency response slope (cutoff attenuation rate) and stopband attenuation depth are determined by transmission zeros, the number of which is equal to the filter order. An experimental prototype of a fifth-order lowpass filter on 0.5-mm-thick

Abstract An ablation of a thin layer of surface contamination of the target that self-recovers after each pulse of a powerful ion beam has been used to control ion fluences. Using a time-of-flight optical spectrometer, the average speeds of the lightest components of the ablative plasma, which are hydrogen and carbon, have been measured. and the ion fluence has been determined by their difference.

Abstract The mode of generation of picosecond optical pulses in the spectral range near 1064 nm by semiconductor lasers with distributed feedback and active region based on an InGaAs/GaAs quantum well has been studied. In the gain-modulation mode, the width of laser pulses decreases from 150 to 35 ps as the temperature increases from 5 to 50°C. It was demonstrated that there is a temperature range

Abstract The contribution of residual atmosphere gases to the flux of collectively accelerated protons in a Luce diode has been determined by comparing the number of protons generated by anodes made of polyethylene and pyrolytic boron nitride. Radioactivation diagnostics based on the nuclear reactions 10B(p, α)7Be and 12C(p, γ)13N has been used to determine the mean number of protons per pulse and

Abstract Nonlinear optical microscopy techniques have been used to study thin films of single-phase (perovskite) and two-phase (perovskite–pyrochlore) lead zirconate titanate (PZT) deposited on Pt/TiO2/SiO2/Si by means of radio-frequency magnetron sputtering at various target–substrate distances (D = 30–70 mm). Results revealed inhomogeneous distribution of second-harmonic generation in spherulitic

Abstract Epitaxial aluminum nitride (AlN) layers on Si(111) substrates have been grown by sequential application of several techniques including reactive magnetron sputter deposition to a thickness of 20 nm, metalorganic vapor-phase epitaxy (MOVPE) to a total thickness of 450 nm, and hydride vapor-phase epitaxy (HVPE) to a final thickness of 2 μm. Synthesis of AlN layers by this combined method provides

Abstract Coatings are fabricated using plasma-ion sputtering and codeposition of ultradispersed Ta and Cd particles and Nb- and Mo-doped W and Cd particles. The fabricated coatings consist of a mixture of crystallized cadmium and the amorphized refractory metals. Subjecting the coatings to thermal annealing in vacuum at 800°C for 1 h results in complete evaporation of cadmium from the coatings and

Abstract—A new method is proposed for studying relaxation and transient processes in ferroelectric ceramics under the influence of a constant electric field. Precision measurements of the time dependences of the complex permittivity of ferroelectric ceramics in the region of weak electric fields were carried out using the method of impedance spectroscopy. A comparative analysis of various methods for

Abstract We report results of the first investigation of dusty plasma formed in glow discharge in the region of a strongly inhomogeneous magnetic field with a field gradient estimated at 2 × 103 G/cm, where a stable magnetic trap has been found. Geometric characteristics of the dusty plasma structure were determined, and the angular velocity of plasma rotation in several sections perpendicular to the

Abstract The influence of dynamic preload on the fatigue endurance limit of AMg6 alloy has been experimentally studied in a range of 109 loading cycles. It is established that prestraining up to 10% deformation at 103 s–1 rate leads to a 22% decrease in the fatigue endurance limit. A mathematical model is proposed that can adequately predict fatigue fracture, including that after preload.

Abstract The effect of induced mechanical activation of radio-frequency superradiance in a parametric mode under the action of an external rheological explosion at high pressure on a paramagnetic composite—a system of crossed spins based on binuclear complexes Co (QH)2–O–Co(QH)2 or Mn(QH)2–O–Mn(QH)2 (QH is a ligand based on 3,6-di-tert-butylpyrocatechol) in a polystyrene matrix—is found. Possible methods

Abstract In this paper, we examine the issues of the formation and propagation of melted zones during electric explosion of thin aluminum films on the oxidized silicon surface. A difference in the formation and propagation mechanisms of melted zones on the surface during the passage of a current pulse and after it was switched off is found. After the current pulse is switched off, the migration of

Abstract The mechanisms of current transport through indium antimonide quantum dots (QDs) have been examined by analyzing normalized differential tunneling current–voltage characteristics. Electron tunneling with the discrete spectrum of QDs taken into account has been studied. The positions of the first three levels of their electronic spectrum have been estimated. It has been demonstrated that the

Abstract Results of designing and studying a prototype of an active element on copper bromide vapors with continuous control of the energy of each radiation pulse are presented. It is distinct feature in featuring implementation of the above mode for a gas-discharge tube with a large volume (above 1.5 L) and formation of the radiation by an unstable cavity. In doing this, a hydrogen-containing addition

Abstract In the framework of the model of cold hydrodynamics, acceleration of the flow of dusty plasma in azimuthal electric and radial magnetic fields has been studied. The obtained results show that there are conditions under which macroscopic particles are captured and accelerated by the plasma flow.

Abstract Single-mode lasing of quantum-cascade lasers with a distributed Bragg reflector formed by ion-beam etching in layers of the upper waveguide cladding is demonstrated. The active region is formed based on an In0.53Ga0.47As/Al0.48In0.52As solid-alloy heteropair with two-phonon depletion of the lower level in the cascade. Single-mode lasing at a temperature of 280 K corresponds to the emission

Abstract We present an experimental approach using the microfluidic techniques, optical microscopy, and high-speed imaging to study the demulsification of water-in-oil emulsions under the action of a nonuniform alternating electric field. The parameters characterizing the demulsification dynamics are estimated. The approach can be used to develop effective methods for water-in-oil emulsions treatment

Abstract A unified analytical technology based on the integration of scanning probe nanotomography and optical microscopy (SPNT–OM) is presented, and the potential of the technology is demonstrated by the example of a multiparameter analysis of encoded microspheres. The presented SPNT–OM technology can become a powerful tool for multimodal nanocharacterization of a wide range of microparticles, composites

Abstract In this Letter, we experimentally study the temperature dependence of the thermal radiation spectra of an Al2O3 : Ti3+ single crystal in the visible and near-infrared regions of the spectrum under laser-thermal heating. The thermal spectra of Al2O3 : Ti3+ in the temperature range of T = 330–900 K were found to differ significantly from the blackbody radiation spectrum and to be selective with

Abstract We consider a method of detrended fluctuation analysis (DFA method), which enables the study of long-range correlations in nonstationary processes. Its modification is proposed, including the calculation of additional quantity, that is, a scaling index, characterizing the effects of nonstationarity in the experimental data. Using the dynamics of the blood flow velocity in cerebral vessels

Abstract The influence of proton irradiation at high temperatures (“hot” irradiation) on the capacitance–voltage and current–voltage characteristics of semiconductor devices based on silicon carbide has been studied for the first time. The experiments were performed on commercial high-voltage integrated 4H-SiC Schottky diodes with a blocking voltage of 1700 V, which were irradiated by 15-MeV protons

Abstract Thin aluminum nitride (AlN) films have been synthesized by reactive ion–plasma sputtering (RIPS) and their properties have been studied in view of using this method for obtaining protective coatings on output facets of high-power semiconductor laser cavities based on AlxGa1 −xAs/GaAs heterostructures. Investigations by energy-dispersive X-ray spectroscopy and ellipsometry techniques showed

Abstract The possibility of designing a compact source of soft X-ray radiation without the accompanying generation of fast electrons is under study. The source is formed by the interaction of high-contrast femtosecond laser pulses of relativistic intensity with supersonic argon gas jets. The optimal conditions are found under which the conversion coefficient to soft X-ray radiation in the range of

Abstract The level of a sonic boom that occurs in a supersonic air flow around two bodies—a disk and a thin revolving body—is calculated. The bodies are placed one after another. The thin body is in the aerodynamic shadow of the disk. The Mach number of the incident flow is 2. The calculations are performed using the combined body phantom method. By varying the position and size of the disk, it is

Abstract It is shown that transient processes arising in the growth chamber of a molecular beam epitaxy (MBE) system influence the structure of interfaces and electron spectrum of quantum wells in GaAs/AlxGa1 –xAs heterostructures used for the creation of photodetectors (PDs) operating in the mid-IR range. These processes lead to a low-frequency shift of the PD operating transition, appearance of interband

Abstract Some results of the numerical calculation of the electron ground state energy and electron density in tunnel-coupled InAs/GaAs quantum dots composing a simple cubic superlattice are presented. The calculation is performed within the modified effective mass method taking into account the microscopic (atomic) structure of individual quantum dots without taking spin-orbit coupling and strain

Abstract Stress–strain diagrams (σ–ε curves) have been studied during uniaxial compression of Ni49Fe18Ga27Co6 alloy single crystals in the [011] axis direction for the initial samples and those after 15-min annealing at 1373 K with subsequent quenching in water. It was established that the σ–ε curves of initial crystals exhibited a one-stage character and showed a single stress decay, whereas the curves

Abstract GaN heterostructures on silicon substrates have been grown by metalorganic chemical vapor deposition. Transistors with the gate periphery of 1.32 mm are designed. The saturation power of the package die at a frequency of 1 GHz was 4 and 6.3 W at supply voltages of 30 and 60 V, respectively. The maximum drain efficiency is 57%.

Abstract Magnetocaloric properties of Gd(Ni0.98Si0.02) and Dy(Ni0.95Si0.05) compounds and their hydrides Gd(Ni0.98Si0.02)H3 and Dy(Ni0.95Si0.05)H4 have been studied in a temperature interval of 2–100 K. It is established that the partial substitution of Si atoms for Ni atoms and subsequent hydrogenation can lead to significant changes in the Curie temperature, magnitude of the magnetocaloric effect

Abstract A technique that allows one to form thick thermomigration silicon layers heavily doped with gallium for prospective power electronic devices is proposed. The dependences of the perfection of structure and the composition of the layers on the temperature of their formation were studied by the methods of X-ray topography, X-ray reflection curves, and secondary-ion mass spectrometry. It is established

Abstract Concentrator photovoltaic units based on Fresnel lenses and secondary concentrators—hollow focons made of sheet aluminum—have been developed. To increase the efficiency of sunlight conversion, the optimal configuration of focons was determined and the photoelectric characteristics of the units were examined. The use of focons provided an increase in the admissible misorientation angle of the

Abstract Composite materials based on a 5xxx series aluminum alloy strengthened with 0.1 wt % of multiwalled carbon nanotubes (MWCNTs) or 0.1 wt % WC1 –x/MWCNTs were synthesized by high-energy ball milling and subsequent gas extrusion. The structural phase composition and physicomechanical properties of bulk composites are characterized. A comparison with published data on the properties of composites

Abstract A design of a fully solid-state thin-film lithium-ion battery prototype and results of its being tested are presented. It is shown that the specific features of its charge–discharge characteristics are associated with the change of the Fermi level in the electrodes and are due to changes in the concentration of lithium ions in the course of charge–discharge. The specific capacity characteristics

Abstract The ranges of H and D ions in crystalline Si and W have been calculated. It is shown that the depth distribution of the ranges is divided into two components with an increase in the ion energy: one is related to the atomic scattering in surface layers, while the other characterizes particles captured into the channel. A new phenomenon has been observed: a stable spatial structure of the beam

Abstract A complex physicomathematical model of heat transfer in packets of cooled microrocket gas-dynamic planar nozzles used for the pumping of gas-dynamic lasers is presented. A small size (~15 mm), due to which they are quickly heated up and require intense heat removal, is a specific feature of such rocket nozzles. The complex physicomathematical model of heat transfer and gas dynamics, as well

Abstract The sensitivity of nanoporous silicon-based binary mixtures with different oxidizing agents to mechanical effects (impact and friction) has been experimentally determined on K-44-1 and K-44-3 shock machines. The results obtained are compared with the data on the sensitivity of regular initiating explosives.

Abstract An experimental and numerical approach for studying the bubble deformation on the surface in the shear flow of viscous liquid is developed. The numerical approach is based on the boundary element method for the Stokes flows. The methods of optical microscopy and high-speed recording are applied for the experimental investigation of the bubble deformation. The dynamics of the variation in the

Abstract The possibility of generating ultrabroadband chaotic oscillations within a frequency range up to 60 GHz with a bipolar SiGe heterojunction transistor is demonstrated. The uppermost frequency of this range is determined by the cutoff frequency of the active generator element. Such a possibility appears after the generator structure is complemented with an additional nonlinear circuit, in which

Abstract Experimental data obtained by the calorimetric method enable analyzing the energy storage capacity of phase-change materials based on n-alkanes. It is shown that a set of n-alkanes with the number of carbon atoms in the chain from 9 to 36 can be used to create comfortable living conditions for people in the temperature range from –50 to 70°C.

Abstract The postgrowth processing of mesa structures for multijunction solar cells based on GaInP/GaInAs/Ge heterostructure has been studied. Methods of wet chemical and electrochemical etching are considered, and a technology of forming a separation mesa structure is proposed that ensures improved surface quality and profile of the side wall of a mesa for heterostructures with various compositions

Abstract Parameters of terahertz (THz) emission in two-dimensional (2D) tungsten diselenide (WSe2) film grown by chemical vapor deposition from the gas phase have been studied for the first time. The main mechanism of THz radiation generation in this system is established. Dependence of the THz signal amplitude on azimuthal angle in a 2D WSe2 film has been studied. The distribution of the electric

Abstract Efficiency of the transmission of high-frequency signals by semiconductor plasma antennas based on Ge and Si single crystals with surface nonequilibrium electron-hole plasma generated by laser diode radiation has been experimentally studied. Dependences of the amplitude of a radiated 6- to 7.5-GHz microwave signal on the laser power and size of the laser-irradiated region on the semiconductor

Abstract Photographs and spectra of single-bubble sonoluminescence of a bubble moving in pure water and aqueous solutions of \({\text{Ru}}({\text{bpy}})_{3}^{{2 + }}\) are obtained. It is shown for ruthenium complex solutions that there are luminescence regions outside the main trajectory of motion of the luminous bubble, which are absent in pure water. The observed spatial localization of these regions

Abstract Spectral characteristics of the Ga(In)As subcell of triple-junction GaInP/Ga(In)As/Ge solar cells have been experimentally and theoretically studied. It is established that the use of a wide-bandgap “window” layer with optimum thickness (100 nm for Ga0.51In0.49P, 110 nm for Al0.4Ga0.6As, and 115 nm for the Al0.8Ga0.2As) in Ga(In)As subcell allows the response photocurrent to be increased by

Abstract The dependence of random telegraph noise (RTN) amplitude on the gate overdrive in a junctionless field-effect transistor (FinFET) with rectangular and trapezoidal channel (fin) cross sections manufactured using silicon-on-insulator technology has been numerically simulated. It is established that the RTN amplitude in the subthreshold region of gate voltages for a FinFET with a trapezoidal

Abstract Thin aluminum nitride (AlN) films on sapphire (Al2O3) substrates were grown by means of ion-beam deposition (IBD) and studied by methods of scanning electron microscopy, Raman scattering, and optical transmission spectroscopy. Results revealed the influence of IBD process parameters (gas mixture composition, ion beam energy, and substrate temperature) on the morphology, structure, and optical

Abstract We describe a model of a stable, metal-modified heteromolecule based on a hybrid of diamondene and graphene containing hydrogen atoms for the stabilization of sp3 bonds. Hydrogen atoms were replaced by atoms of carbide-forming metals (Fe, Co, Ni). After the replacement of H atoms by Fe, Co, and Ni atoms in the initial heteromolecule and optimization of its geometry, it turned out that the

Abstract Epitaxial Sr0.5Ba0.5Nb2O6/MgO thin films with layers of differing thickness (but with identical total thickness) have been prepared by radio-frequency magnetron sputtering with application of discontinuous deposition technology. It is established that a decrease in the layer thickness intensifies the unit-cell deformation, which is retained if the thickness of subsequent layers does not exceed

Abstract An ensemble of van der Pol oscillators coupled in a ring has been numerically simulated. Peculiarities of chaotic dynamics have been studied by analysis of Fourier spectra and Lyapunov exponents. It is established that chaotic dynamics appearing upon the breakup of multifrequency tori is characterized by a broadband spectrum.

Abstract Spatio-temporal distributions of radiation from pulsed sliding surface discharge of ~300-ns duration in quiescent air at pressures within 2–200 Torr and in the presence of shock waves in supersonic flow with Mach numbers M = 2.8–3.3 have been experimentally studied. The dynamics of radiation from discharge was analyzed based on processing of the streak images and nine-frame images of discharge

Abstract The design of a simple compact cryothermostat intended for studying the influence of γ irradiation on the optical losses of single-mode fluorosilicate optical fibers operating at a 1.31-μm wavelength is described. It is established that the radiation resistance of these optical fibers increases as the test temperature is decreased from +25 to –60°C.

Abstract We present the results of a theoretical study of the electrodynamic characteristics of fast and slow electromagnetic waves (EMWs) propagating in a metamaterial consisting of a ferromagnetic film inside which there is a periodic lattice of thin metal wires. The ferromagnetic thin-film metamaterial possesses the properties of a left-handed medium at frequencies of slow electromagnetic waves

Abstract We consider a new promising approach to the combustion of water-saturated hydrocarbon fuels in the form of foamed emulsions, stable combustion of which can sometimes be maintained at a water content above 90% mass %. Theoretical analysis and numerical simulations demonstrated the basic physical mechanism determining these broad combustibility limits, which consists in the natural spatial separation

Abstract Current–voltage characteristics of composite field-effect transistors with active layers based on inorganic perovskites, nanocrystals of cesium halides CsPbBr3, embedded into the matrix of a semiconductor polymer PFO (PFO:CsPbBr3) have been analyzed. An increase in current gain β in current–voltage characteristics of structures of this kind with increasing negative gate voltage was found and

Two-dimensional interaction of a shock in air with elliptic area (two-dimensional gas bubble) filled with propane-oxygen mixture with addition of heavy gas is numerically studied using Euler’s equations. Propane combustion is modeled with one-stage Arrhenius kinetics. Three different ignition regimes are found: direct detonation initiation by sufficiently strong shock, detonation near the triple point

Abstract A strong dependence of the optical breakdown in a liquid in the ultrasonic field on the amplitude and frequency of ultrasound is demonstrated. The increase in the intensity of spectral lines of potassium and oxygen during the optical breakdown is detected by the increase in the amplitude and frequency of ultrasound. At the same time, the effect of saturation is observed at high frequencies