Abstract The Young’s modulus of a finite-sized zigzag carbon nanotube-based ribbon-like columnar graphene is theoretically studied. The dependence of elastic characteristics on the structural parameters of columnar graphene such as the length and diameter of carbon nanotubes constituting the composite is studied. In this case, within the limits of a particular composite, the structure parameters of

Abstract Justification and generalization of the glass transition criterion of Schmelzer is proposed with the involvement of the model of delocalized atoms. Unlike the approaches of Bartenev and Vol’kenshtein–Pti-tsyn, in the generalized kinetic criterion of glass transition, the glass transition temperature and almost universal dimensionless constant (determining by the part of the fluctuation volume

Abstract The above-barrier glide of edge dislocations in binary alloys containing Guinier–Preston zones under high-energy impacts was theoretically analyzed. It was shown that the dependence of the yield stress of these alloys on the dislocation density in conditions of high-rate deformation deviates from the Taylor relationship and is a nonmonotonic function with a maximum. The maximum point corresponds

Abstract This study presents the reliability of diamond-like carbon (DLC) ultrathin films fabricated by DC magnetron sputtering as the gate dielectric layer in metal–insulator–semiconductor (MIS) devices. Stress-induced leakage current (SILC) and time-dependent dielectric breakdown (TDDB) measurements were performed to determine the reliability of the devices. The MIS device with DLC film deposited

Abstract The relaxation processes in polycrystalline PZT films formed on silicon substrates have been studied during a quasi-static change in an external electric field. The dielectric relaxation is shown to be characterized at least by three relaxation times depending on the direction of the self-polarization in the film, the value of the polarizing field, and also the PZT film annealing temperature

Abstract An increase in the static strength of materials operating in extreme service conditions does not enable one to judge the reliability of resulting products. This report describes the features of material deformation observed as the deformation rate increases in the cases of aluminum and titanium alloys. The possibility of choosing a material for given service conditions is discussed in terms

Abstract The correlation between the mechanical properties of a material in microvolumes and the material under a load has been studied. A fractographic analysis is performed for the surface of fatigue failure of a railway rail with an internal cross crack. The correlation of the fractographic features with the material structure is discussed. A sample with an internal cross crack in the rail head

Abstract The structure of a powder germanium treated in a planetary mill in the presence of small (5–25%) additions of diamond powder has been studied by high-resolution transmission electron microscopy using a JEM-2010 electron microscope. As a result of the treatment, twins and stacking faults have been detected in germanium along plane (111). The germanium deformation is shown to lead to the polytypism

Abstract The formation of iron silicide thin films under graphene grown on the silicon carbide surface is investigated. The thin films are synthesized by consecutive intercalation of iron and silicon atoms into the graphene. Experiments are carried out in situ in ultrahigh vacuum. The elemental composition and chemical state of the surface of prepared samples and their atomic structure are determined

Abstract Using a pseudo-potential approach within the virtual crystal approximation, the elastic properties of YxIn1 – xN semiconductor ternary alloys in the hypothetical zinc-blende phase have been investigated. The results obtained for InN show a reasonable agreement with data available in the literature. Other case, our findings are the first predictions for alloys in question. The composition dependence

Abstract The properties of long cylindrical superconductors with a diameter comparable with coherence length ξ have been investigated in the framework of the Ginzburg–Landau theory. The equations of the theory have been solved using the general boundary conditions for the order parameter. The use of such boundary conditions makes it possible to take into account the effect of the boundary of a cylinder

Abstract New environmental-friendly lead-free barium calcium stannate titanate (BCTS)–Portland cement (PC) composites were studied and fabricated to be compatible with the concrete structures for sensors and smart-structure health-monitoring applications. The lead-free composites were produced by pressing and curing techniques. The effect and optimum of BCTS content on properties of composites were

Abstract The electronic structure of an ultra-thin molybdenum oxide film obtained by oxidation of molybdenum at an oxygen pressure of 1 Torr and the effect of adsorption of sodium atoms on its electronic structure are studied by photoelectron spectroscopy. Photoemission spectra from the valence band and core levels of O 2s, Mo 3d, Mo 3p, and Na 1p are studied upon synchrotron excitation in the photon

Abstract The near-edge luminescence of zinc oxide epitaxial film grown via molecular-beam epitaxy on a sapphire substrate is studied. Upon an increase in optical excitation at room temperature, the luminescence spectrum changes radically and a new band appears with a maximum of ~3.17 eV. It has features of stimulated emission, i.e., a threshold of nonlinear growth and a narrowing of the half-width

Abstract The determination of the breakdown voltage and the diagnostics of the prebreakdown state of a material is a topical problem of studying characteristics of insulating materials and structures based on them when applying an external electric field. The new effective method of the diagnostics of the prebreakdown state of multilayer structures (MLC) based on the ferroelectric–relaxor 0.55Pb–Mg1/3Nb2/3O3–0

Abstract The structure, dielectric characteristics, and magnetoelectric effect of a 0.5BiFeO3–0.5PbFe0.5Nb0.5O3 multiferroic ceramics are studied. We found that the ceramics is pure and has a structure similar to that of cubic one with a = 3.999(5) Å at room temperature, which is retained within 20–600°C. We showed that the 0.5BiFeO3–0.5PbFe0.5Nb0.5O3 solid solution possesses both ferroelectric and

Abstract Optical properties of titanium dichalcogenide compounds, TiX2 (X = S, Se, and Te) have been calculated by first-principles calculations using density functional theory as implemented in SIESTA code. The unit cell of each of these compounds was optimized and the calculations were performed to obtain the optical properties. Further, external electric field (along Z direction) and biaxial strain

Abstract The thermoelectric characteristics of carbon nanotubes are studied theoretically. The behavior of the differential thermal EMF of single-layer carbon zigzag-type nanotubes is studied in an external longitudinal dc electric field. The dynamics of the electron subsystem of the nanotubes is described using the Boltzman kinetic equation in terms of the quasi-classical approximation of relaxation

Abstract The brownmillerite phase has been studied by X-ray diffraction and Mössbauer methods. The available data on single-phase compounds with the perovskite structure in strontium ferrite SrFeO3 – δ are analyzed. All the valence states of iron for any phase state of strontium ferrite are found to be determined by its local oxygen environment. This fact enables us to understand the regularity of

Abstract Layered magnetic films of Co–P alloy, which are sets of laminates with certain atomic and chemical structures, have been investigated by spin-wave resonance. Coatings of two types were synthesized: a magnonic crystal (amorphous Co(P)/fcc Co(P))N and gradient Co(P) films. They exhibit two different modifications of the spin-wave resonance (SWR) spectrum. In the first case, the SWR spectrum

AbstractThe dynamics of the magnetization vector of the free layer of a layered spin-valve structure has been simulated. As materials for a free and fixed layer, we have considered six magnetically soft ferromagnets with planar anisotropy. The types of magnetization dynamics being of practical interest for MRAM and HMDD (magnetization vector switching), STNO (stable precession of the magnetization

AbstractThe main parameters of the tunnel barrier of Josephson Nb/AlOx/Nb and Nb/AlN/Nb junctions are estimated in a wide range of the current density using the Simmons method. The dependences of the tunnel barrier height and width of the resistivity are determined experimentally for each type of the junctions. A decrease in the tunnel barrier height of the junction with the AlN interlayer by 0.3 eV

AbstractThe transport properties of two types of quasi-one-dimensional superconducting microstructures were investigated at ultra-low temperatures: the narrow channels close-packed in the shape of meander, and the chains of tunneling contacts “superconductor-insulator-superconductor.” Both types of the microstructures demonstrated high value of high-frequency impedance and-or the dynamic resistance

AbstractThe microwave and magnetic parameters of Josephson Nb/Au/Sr2IrO4/YBa2Cu3Ox mesastructures with a layer of Sr2IrO4, a material representing a Mott antiferromagnetic insulator with a high spin–orbit interaction energy ESO ~ 0.4 eV, were studied. Shapiro steps, oscillating with radiation power, appeared under monochromatic electromagnetic radiation confirm the Josephson properties of these structures

AbstractThe pseudogap phase of HTSC cuprates is associated with the formation of a system of quantum electron–hole (EH) dimers similar to the Anderson RVB phase. A specific role of the electron–lattice relaxation in the formation of metastable EH dimers in cuprates with the T and T ' structures is considered. An effective spin–pseudospin Hamiltonian of the CuO2 plane of cuprate is introduced in the

AbstractThe article studies the attenuation of vacuum Rabi oscillations for a system of two superconducting solid-state qubits placed in a high-Q microwave cavity. Two different cases are considered in which: 1) the first qubit is excited at the initial time and 2) the initial state comprises an entangled symmetric and antisymmetric pair of states. The dependence of the attenuation on various parameters

AbstractWe study the influence of the accumulation layer on the spectral properties of semiconducting nanowires fully covered by a superconducting shell within the framework of the Bogoliubov–de Gennes equations. It is shown that both the decrease in the thickness of the layer and the increase in the ratio of the Fermi velocities in the shell and the core result in the enhancement of the spectral gap

AbstractThe original research results for thin disordered HTSC films based on YBCO are presented in this article. Several experiments have been carried out to confirm a theoretical prediction that the s-phase of superconducting pairing in disordered d-type superconductors can occur with a gradual decrease in the mean free path. The YBa2Cu3O7 – x films are used as samples which possess a d-type of superconducting

AbstractTwo types arrays of annular half-wave and electrically small antennas with typical sizes of the elements corresponding to 1/10 of the wavelength at SubTHz band with integrated superconductor–insulator–normal metal–insulator–superconductor (SINIS) bolometers have been developed, fabricated and experimentally studied. We performed numerical modeling of the full structure and use additional reference

AbstractMechanisms that are responsible for the optical harmonics generation at exciton transitions are analyzed in several classes of materials. In the cubic GaAs semiconductor, the magneto-induced optical second-harmonic generation second optical harmonic is observed in the region of orbital quantization of the valence and conduction bands. An unusually strong amplitude of the optical third-harmonic

AbstractThe features of spin injection into a helicoidal ferromagnet are investigated. Two methods of spin injection are considered: injection of a spin-polarized current and spin pumping. For the case when the axis of the helicoid is perpendicular to the interface through which the spin injection occurs, the conditions are determined under which electrons fill the specified spin subband. For the case

AbstractTaking into account the difference in the mobilities of electrons with different spin projections, the frequencies of spin-injection radiation in the current-carrying magnetic contact formed by two ferromagnets are calculated. It is shown that these frequencies are in the terahertz range at a certain current density exceeding the threshold value, and the current density required to generate

AbstractThe method of nonlocal trial variation function for quantum one-dimensional systems is developed on an example of a spin-1/2 XXZ chain with an alternating magnetic field. A four-site trial wave function for a fermionic representation of the model is constructed. The results obtained using the model with the extended trial wave function show a considerable improvement of accuracy of the ground

AbstractBased on PET track etched membranes, arrays of layer nanowires 100 nm in diameter, consisting of alternating Ni/Cu and Co/Cu layers are grown by the matrix synthesis method. Galvanic deposition processes are studied and conditions for fabricating layer nanowires with different thicknesses for magnetic (Ni or Co) and nonmagnetic (Cu) layer components are determined. An electron microscopic study

AbstractThe paper presents theoretical model of a straintronics magnetoelectric random-access memory (MeRAM) storage cell with configurational anisotropy. The MeRAM cell consists of ferromagnetic layers with different orientations of the quasi-uniform magnetization, which is divided into identical magnetic tunnel junction’s ferromagnet|insulator|ferromagnet, in the form of a sandwich of planar layers

AbstractA correlation was found between the endset temperature of the superconducting transition T(R = 0) of YBa2Cu3O7 – x films 100–200 nm thick, obtained by pulsed laser deposition on SrTiO3(100) substrates with a temperature of ~740°C, and the regimes of high-speed filtering of the erosion plume formed upon ablation of the material the target. Under deposition conditions, we changed the width of

AbstractA bolometer, which is based on a superconductor–insulator–normal metal–insulator–superconductor (SINIS) structure, integrated into a twin-slot antenna with a central frequency of 90 GHz, and connected with a superconducting microwave readout resonator, has been designed, fabricated, and experimentally studied. Such an elementary cell is designed for the multi-element array of a high-sensitive

AbstractThe memristive properties of layered capacitor structures based on a (Co40Fe40B20)x(LiNbO3)100 – x nanocomposite and LiNbO3 with thicknesses of 10 and 40 nm, respectively, are studied. There was a sharp transition from a single-filament to multi-filament resistive switching mechanism observed for the first time which appeared with an increase in an amount of the metal phase in the nanocomposite;

AbstractThe effect of structural properties on the formation of the perpendicular magnetic anisotropy in Co/Dy superlattices has been studied. The superlattices are found to be composition-modulated alloys in which, on the one hand, a rigid periodicity in thicknesses and compositions takes place and, on the other hand, the interdiffusion of Co and Dy at interlayer boundaries leads to a periodic change

AbstractThe frequency dependences of the transmission coefficient of surface magnetostatic waves (SMSW) propagating in subwavelength magnonic structures obtained by deposition of 1D and 2D thin-film metastructures based on a 40-nm-thin permalloy film on the surface of an yttrium–iron garnet (YIG). These structures lead to a modulation of the damping and the effective internal magnetic field in the

AbstractThe magnetocaloric effect in a two-dimensional Ising model is considered for different ratios between parameters of inter-site repulsion of nonmagnetic impurities and exchange coupling. Classical Monte Carlo simulations on a square lattice show that in case of weak coupling and at sufficiently high concentrations of nonmagnetic impurities the long-range ferromagnetic ordering breaks down to

AbstractThe properties of a dilute Ising magnet are studied using a two-dimensional spin–pseudospin model with charged impurities and a frustration caused by the competition of the charge and magnetic orderings. Based on the classical Monte Carlo method, the ground state phase diagram has been obtained and also unusual phase states appeared at finite temperatures have been studied. The regions in which

AbstractBolometers based on the superconductor–insulator–normal-metal–insulator–superconductor (SINIS) structure with an absorber suspended above the substrate are developed, fabricated, and experimentally studied in the terahertz frequency range. In contrast to the previously studied bolometers with an absorber located directly on the substrate, the real bolometric mode of operation is achieved, i

AbstractMicromagnetic modeling of ferromagnetic resonance (FMR) is carried out in a system comprising a cylindrical stack consisting of three ferromagnetic nanodisks, in which a helicoidal distribution of magnetic moments is realized due to magnetostatic interaction in the equilibrium state. Specificities of the rearrangement of the FMR spectrum and the spatial structure of the resonant oscillations

AbstractThe changes in the domain structure of CoNi microparticles under action of mechanical stresses have been studied. With this purpose, an array of identical planar square CoNi particles has been formed on the surface of a polished glass substrate. An elastic bending of the substrate has been used to induce mechanical stresses in the particles. It is shown, using magnetic-force microscopy, that

AbstractComposites FemOn–Fe3 – xTixO4 have been synthesized using the sol–gel method and hydrothermal treatment. The conditions chosen for the synthesis favor the formation of composites containing titanomagnetite in a relatively low concentration. The theoretical analysis of the magnetic properties of the composites is performed based on the hysteresis curves and the temperature dependences of the

AbstractWhen manufacturing YBCO structures using traditional methods, a certain compromise is usually reached, namely: films with the relevant morphology, but with low electrophysical parameters are used. In this paper, it is shown that YBCO bridges 4 μm in width with the perfect surface morphology, i.e., without defects, with the critical current density Jc ≥ 3 × 106 A/cm2 at temperature 77 K and

AbstractIn antiferromagnetic (AFM) nanoparticles, an additional ferromagnetic phase forms and leads to the appearance in AFM nanoparticles of a noncompensated magnetic moment and the magnetic properties typical of common FM nanoparticles. In this work, to reveal the regularities and differences of the dynamic magnetization switching in FM and AFM nanoparticles, the typical representatives of such materials

AbstractIn the second order of the operator form of the perturbation theory, the effective interactions in a superconducting nanowire have been obtained at the strong electron correlations, when the spin–orbit coupling parameter is comparable with the hopping integral. Using the exact diagonalization technique, in short nanowires with the open boundary conditions at the strong Coulomb repulsion, the

AbstractNanowires have been formed from FeNi and FeCo alloys by the template synthesis method based on galvanic filling of pores of track membranes. A change in the nanowire elemental composition with a change in the electrolyte composition and with a change in the deposition potential has been studied. FeNi nanowires exhibit the effect of anomalous Fe codeposition: the iron content in the nanowires

AbstractComputer experiments were carried out using the molecular dynamics method to study systems of magnetic ellipsoidal nanoparticles with two different dipole orientations inside each particle. Magnetic moments directed parallel or perpendicular to the main axis of rotation are considered. The initial susceptibility of the system is investigated and cluster analysis is carried out. The results

AbstractThe influence of light exposure on the magneto-optical Kerr effect in the ferromagnetic semiconductor europium sulfide EuS has been studied. It has been experimentally established that when a sample is exposed to the light with a photon energy greater than the band gap, photoinduced magnetization occurs, which is associated with the formation of magnetic polarons with a large magnetic moment

AbstractAn electromagnetic source of terahertz radiation on the basis of a tunnel long Josephson junction was proposed and experimentally studied. Output radiation was transmitted to open space by means of a slot antenna, which was located on the same microcircuit with the junction and matched with the collecting lens. Several Oscillator structures designed for operation within the frequency ranges

AbstractWe report on the investigations of the magnetic properties and ferromagnetic resonance in the heterostructure consisting of an epitaxial yttrium iron garnet (Y3Fe5O12) film and a nanometer rare-earth intermetallic superlattice comprised of the (TbCo2/FeCo)n exchange-coupled layers. The (TbCo2/FeCo)n superlattice exhibits the giant magnetostriction and the controlled magnetic anisotropy induced

AbstractA possibility of contactless switching of an NbN nanowire from superconducting to normal state by passing a current through a gate located at a certain distance from the nanowire is demonstrated. The gate, being isolated from the nanowire by an Al2O3 layer, contains an integrated resistance formed by ion irradiation. Dependences of the minimum power released in the gate that is sufficient for

AbstractHeterostructures of the CdTe/ZnTe type with ultrathin quantum wells are studied. Lines of light and heavy excitons bound to the CdTe layers are observed in the spectra. It is found that the photoluminescence intensity of the light exciton is comparable to the luminescence intensity of the heavy exciton. The temperature shifts of these lines are different, and the lines are intersected at a

AbstractThe features of the scattering of accelerated neutral atoms upon sliding interactions with crystalline surfaces are discussed. Particular attention is paid to the phenomenon of rainbow scattering of neutral atoms upon their reflection from an oriented crystalline surface. The physical causes of the arising effects and the possibility of reconstructing the two-particle “polarization” and “dynamic”

AbstractWe studied the electronic structure of gold nanoparticles deposited on a tungsten surface before and after the deposition of sodium atoms with subsequent heating at T = 630 K by in situ photoelectron spectroscopy in ultrahigh vacuum. The photoemission spectra from the valence band and core levels of Au 4f and Na 2p were studied upon synchrotron excitation in the photon energy range of 80–600

AbstractA theory of the magnetoelectric effect in three-layer asymmetric structures composed of a piezoelectric layer and two magnetostriction layers with opposite magnetostriction signs is presented. The thickness ratio of the layers is obtained, at which this effect is maximum. It is shown that the sign of the magnetoelectric coefficient changes to opposite (with respect to the initial two-layer

AbstractThe magnetostatic and magnetic resonance properties of the Y0.5Sr0.5Cr0.5Mn0.5O3 polycrystalline system have been experimentally investigated. The predominance of the intracrystalline ferromagnetic interaction and the antiferromagnetic character of the intercrystallite interaction have been established. The magnetic resonance spectrum in the magnetically ordered region consists of two lines