Abstract Impurity Cr2+ ions in the CdSe crystal are studied by tunable EPR spectroscopy in the frequency range of 70–320 GHz. The discovered Jahn–Teller tetragonal distortions of the nearest environment of the chromium ion confirm the results of recent ultrasound studies. The set of spectroscopic parameters that allows obtaining agreement between the calculates and experimental angular and field–frequency

Abstract Behavior of a titanium alloy is studied under conditions of a high-speed penetration at a speed of ~2.0 km/s. Three penetration zones with different mechanisms of plastic deformation and fracture are observed in a target during its punching.

Abstract In a Li2CaSiO4 crystal, tetragonal Cr4+ centers (electron configuration 3d2, spin S = 1) are identified and investigated by the ESR method at different frequencies. The magnitude of zero-field splitting is determined. An additional signal with a reverse phase is observed in the region, in which the positions of the two transitions of Cr4+ coincide. For an uncontrolled impurity of Mn2+ ions

Abstract The exciton photoluminescence of zinc oxide is studied in the temperature range 5–300 K. The formation of the exciton emission band profile in the spectra of undoped crystals, high-purity powder, and thin ALD films 4–450 nm in thickness at 300 K and at excitation by a He–Cd laser is analyzed. The effects of the photodesorption and photoadsorption of atmospheric oxygen on the exciton emission

Abstract Phase transitions in the mixture of powders C6H16NBr (DIPAB) and PbTiO3 and composites x-bTiO3–(1 – x)C6H16NBr at x from 0.05 to 0.45 have been studied by the differential thermal analysis (DTA) method. The DTA signal is compared to the temperature dependence of dielectric permittivity ε'(T) of the xPbTiO3–(1 – x)C6H16NBr composites. The addition of lead titanate to C6H16NBr is shown to lead

Abstract We obtained a Raman spectrum for a surface layer of porous carbon ceramic (porosity ≈5%) of ≈80 nm thick. The analysis of the spectrum showed that the ceramics contain crystals of silicon carbide 6H‑SiC and silicon. The destruction of ceramics by diamond microcrystals resulted in fractoluminescence (FL). Its spectrum contained two bands at 1.6 and 1.9 eV. The first is emerged at the destruction

Abstract Reflectivity and modulated photoreflectivity spectra of ZnO and Zn1 – xMgxO epitaxial layers as well as ZnO/Zn1 – xMgxO quantum wells have been studied at normal and oblique light incidence. Comparison of experimental and calculated spectra allowed refinement of certain parameters of excitons in these structures and the order of energy bands in ZnO.

Abstract In a series of NiFe/Cu/IrMn structures with a variable effective thickness of the nonmagnetic copper interlayer (up to its absence in the NiFe/IrMn sample), we observed a decrease in the exchange bias and coercive force with an increase in the effective thickness of the copper layer. The coalescence of copper islands when the effective thickness of the copper layer reaches 1 nm changes the

Abstract Thermal vibrations in a d-dimensional (d = 1, 2) scalar harmonic lattice of a simple structure are under consideration. Redistribution of the averaged kinetic and potential energies of particles after instantaneous thermal excitation (fast process) is described. It is established that the difference between the kinetic and potential energies undergoes power-law damped oscillations at times

Abstract Films obtained by radio-frequency sputtering of monocrystalline polydiacetylene (PDA) are under study. The structure is studied by Raman spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. It is shown that the obtained films have a heterogeneous structure containing agglomerates of nanosized inclusions of the initial PDA and irregular sp/sp2 hybridized carbon

Abstract Samples of a homogeneous (x = 0, 0.1, and 0.2) and multilayer ceramics with a gradient composition (x = 0.2 → 0.1 → 0 → 0.1 → 0.2) based on solid solutions of (Ni1 − xZnx)Fe2O4 nickel–zinc ferrites have been manufactured using the thick-film technology. After sintering in a two-step mode, the gradient samples exhibited a smooth non-uniform distribution of chemical elements (Zn, Ni) over the

Abstract Studies of the structure, IR absorption spectra, luminescence spectra, and excitation of luminescence of Ce3+ and Tb3+ ions in crystals of solid solutions of Lu1 – x – yCexTbyBO3 at 0 ≤ x ≤ 0.01 and 0.07 ≤ y ≤ 0.16 have been performed. It has been shown that the solid solution Lu1 – yTbyBO3 synthesized at T = 970°C has the structure of calcite at 0 ≤ y ≤ 0.07, at y ≥ 0.16—the structure of

Abstract The paper presents the results of the long-term experiment on the solid-phase transformation of the Au–Pb metallic system which takes place at room and cryogenic temperatures. It is found that the solid-phase contact interactions between lead and gold lead to the formation of the Pb + AuPb3 eutectoid. The mass transfer and the phase formation are due to the lead extrusion along the percolation

Abstract In a Pt/Co/Ir/Co/Pt synthetic ferrimagnet with perpendicular magnetic anisotropy, a stochastically appearing magnetization peak was found in the field dependence of the magnetic moment at a high sweep rate of the magnetic field of 16 kOe/s and T = 300 K. The peak appears near coinciding switching fields between three equilibrium states of magnetization. The peak is caused by the nucleation

Abstract We have systematically investigated the spin- and valley-dependent Seebeck effect in irradiated heavy group-IV monolayers including silicene, germanene, and stanene by means of semi-classical Boltzmann equation in diffusive regime. Due to the interplay of strong intrinsic spin-orbit coupling, perpendicular electric field, and off-resonant light field, the temperature-driven spin and valley

Abstract We have investigated the magnetic properties of Mn-doped LiZnAs half-Heusler compound using density functional simulations within the gradient generalized approximation (GGA) with the on-site Hubbard Ueff parameter (GGA+U). A detailed study of magnetism in the two compounds GaAs and LiZnAs doped with Mn is presented. A super-cell of 64 and 96 atoms have been built for the zinc blende and the

Abstract The electron-stimulated desorption (ESD) of K atoms from the potassium layer on the KxAuy surface has been found. The KxAuy layer is formed at a tungsten substrate coated with a gold film with thickness no more five atomic layers. A quasi-resonant dependence of the K atom ESD yield on the energy of exciting electrons is observed. The quasi-resonant dependence is due to the excitation of Au

Abstract Investigation of the EPR spectrum of Y3Al5O12:V crystals have made it possible to determine the parameters of the fine and hyperfine structures of trigonal V2+ centers. The existence of V2+ triclinic centers that arise as a result of association of V2+ sites with defects that lower the symmetry is established.

Abstract Anticommutator Green’s functions and energy spectra of the C28 fullerene and the endohedral Zr@C28 fullerene with the symmetry group Td are obtained within the Hubbard model in the approximation of static fluctuations. Using the methods of group theory, the classification of energy states is carried out, and the allowed transitions in the energy spectra of C28 and Zr@C28 molecules are determined

Abstract Nanopowders of zinc sulfide (ZnS) and ZnS/Ag2S heteronanostructures were synthesized by chemical deposition from aqueous solutions. A change in the ratio between the concentrations of reagents allowed us to obtain ZnS nanopowders with a particle mean size from 2 to 10 nm. The Ag2S nanoparticle size in the resulting heteronanostructures was 9–30 nm and the ZnS surface layer thickness was equal

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

Unoccupied electronic states in the energy range from 5 to 20 eV above the Fermi level have been studied in ultrathin films of dimethyl-substituted thiophene–phenylene cooligomers CH3-phenylene–thiophene–thiophene–phenylene–CH3 (CH3–PTTP–CH3) on polycrystalline gold surfaces of two types: the ex situ Au layer thermally deposited in a special chamber and the in situ Au surface prepared inside an analytical

Comparative experimental data, using dynamic light scattering methods, scanning electron and atomic force microscopy, on the composition, crystal structure, semiconductor and photoelectric properties of PbSe films deposited at the presence of sodium sulfite Na2SO3 and “sodium sulfite–ascorbic acid” complex antioxidant additive are presented. Significant changes in morphology, elemental and phase composition

The magnetic structure and the composition of Fe3O4/γ-Fe2O3 nanoparticles are studied at 300 and 80 K with Mössbauer spectroscopy. We found that the Fe3O4/γ-Fe2O3 particles are a core–shell nanocomposite (NC), in which magnetite Fe3O4 is covered with a maghemite shell (γ-Fe2O3). We showed that the thickness of the maghemite shell (γ-Fe2O3) depends on synthesis technology. We found that a layer, whose

Hybrid structures consisting of emitting carbon nanodots bound to the surface of monodisperse spherical silica particles, which function as microresonators, are synthesized. The carbon nanodots are deposited onto the particle surface through controllable coagulation in three different solvents: ammonia, hydrochloric acid, and glycerol. In photoluminescence spectra of hybrid structures, throughout the

A method of synchronous measurement of the piezoresponse signal and electrical impedance when studying the processes of polarization switching in an external electric field has been described. Using the developed technique, the processes of switching ferroelectric (FE) phase of lead magnoniobate induced by an electric field are studied. It is shown that a polydomain structure with a weak piezoresponse

The dynamics of magnetization reversal of a nanocell composed of two magnetouniaxial nanoparticles by a short Gaussian magnetic-field pulse is investigated. This dipole-coupled system is multistable and has four equilibrium states. The conditions, under which the nanocell is switched to one of three states or returns to the initial configuration, are found. It is shown that the character of precession

The results of the study of the shifts of the X-ray K α and K β lines of manganese and copper obtained for the nanoparticles of the oxides CuO, MnO, Mn3O4, and MnO2 (relative to the corresponding bulk materials) are presented. The oxide nanoparticles are synthesized in the pores of borosilicate glass with an average pore diameter of 7 ± 1 nm from the corresponding nitrates introduced into the pores

In order to extract structural and electronic properties of B x In1 –  x As ternary alloys and enrich the database of materials based on boron and indium, we have used full-potential augmented plane wave (FP-LAPW) method through the density function theory (DFT) and within generalized gradient approximation (GGA), local density approximation (LDA), and Tran–Blaha modified Becke–Johnson approximation

This work presents modeling and functioning of nanotube island single-electron transistor (SET), through first-principles approach based on density functional theory and non-equilibrium Green’s function. Ultrathin single-walled carbon (C), boron nitride (BN), and silicon carbide (SiC) nanotubes in armchair (3, 3) and zigzag (5, 0) structures have been adopted as island in the SET model. The nanotube

Degradation of organic pollutants got more attention for detoxification of water. In this paper, pure and Zn-doped Cu2O particles were successfully synthesized by water bath co-precipitation method. X-ray diffraction (XRD) study confirmed the cubic structure of Cu2O. Zn doping resulted in reduction in crystallite size without changing d-spacing and crystal structure. Zn doping converts perfect cube

The possibilities of control of the electrophysical and mechanical properties of amorphous diamond-like silicon-carbon films by means of structural, chemical and structural-chemical modification are considered. The magnitude of the bias voltage and its frequency during the process of film synthesis, argon pressure in working chamber and precursors with different molecular structures are used as factors

Scattering of electrons and holes by a system of deep impurities in gallium arsenide-based semiconductor heterostructures with two quantum wells in the approximation of a maximally localized potential at an arbitrary doping profile has been studied. It is shown that the dependences of the probabilities of electron and hole scattering per unit time on the carrier energy repeat a threshold form of the

Results of an experimental study of the specific resistivity of rare-earth metals and their alloys are analyzed. A procedure to distinguish the contributions into the total resistance is proposed. The magnetic component of electric resistance in the paramagnetic phase was found to decrease to zero upon heating. Modern models of transport phenomena do not describe this phenomenon.

The concentration dependence of magnetic properties of iron alloys with 3–25% of gallium is studied. It was shown that the saturation induction monotonically decreases with increasing gallium content, while the coercivity exhibits a step increase with a step from 85 to 135 A/m between 12 and 15 at % Ga. The effect of magnetic field annealing (MFA) on the behavior of the residual induction and coercive

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