Abstract Various types of magnetic ordering in two-sublattice magnetic materials with exchange interaction were studied using the method of random exchange interaction fields and the Ising model. The conditions for the magnetization of such systems were identified. Equations for the temperatures of phase transitions were derived.

Abstract— This work investigates the formation of an ordered Ti3Al phase (α2 phase) in Ti–Al alloys as a function of the time and aging temperature. High-temperature treatment performed in the single-phase α field and the subsequent aging at different temperatures have been shown to result in more intense precipitation and growth of disperse particles than that resulted from pretreatment in the β field

Abstract The kinetics of the growth of M23C6 carbide particles in 9% Cr martensitic steel with a high boron content is studied under conditions of long-term aging and creep. It is shown that the grain-boundary diffusion is a mechanism that controls the coarsening of these carbides during the aging. Deformation accelerates the coarsening of particles during creep, which can be explained by additional

Abstract An analytical method for determining the vertical asymmetric magnetization distribution in a two-dimensional Bloch domain wall (DW) is proposed in this work. An asymmetric two-dimensional magnetization distribution in a DW is obtained using simple analytical dependences with a minimum number of variable parameters. The structure and energy of the Bloch DW in permalloy-type magnetic films are

Abstract The properties of the Ti50Pd40Ni10 (at %) alloy showing the high-temperature shape memory effect are studied in detail using samples made of a 5.86 mm bar under various conditions of annealing and induced deformation. The data on the phase transformation temperatures and the mechanical and thermomechanical characteristics of the alloy are obtained. The range of phase transformations occurs

Abstract–A material based on the V2AlC MAX phase has been obtained for the first time by the method of self-propagating high-temperature synthesis (SHS) using a reaction mixture of vanadium oxide(V) and (IV) powders with aluminum and carbon (graphite). The obtained material was characterized by X-ray diffraction and energy-dispersive X-ray spectroscopy. The Rietveld method was used to perform quantitative

Abstract A computer simulation of the structure and energy of 〈110〉 symmetric tilt boundaries has been performed for polycrystalline tungsten. Calculations have been made using an embedded atom potential implemented in the LAMMPS software. It has been shown that structure of the 〈110〉 symmetric tilt boundaries can consist of a limited number of structural elements. The energy and width of grain boundaries

Abstract It is shown using model calculations that Maxwell’s relation is exactly satisfied for ferromagnets with one species of magnetic atoms and for two-component ferromagnets and ferrimagnets. This allows one to confidently use this relation for calculating the main characteristics of the magnetocaloric effect in these cases. A conclusion is made that the proposed model of a ferrimagnet is self-consistent

Abstract Nanocrystalline Fe–Cr alloys synthesized from pure components in a planetary ball mill with a chromium content of 20–48 at % were annealed for 4 h at temperatures of Tan = 400–700°C. Short-range order (SRO) evolution and phase separation dependent on Tan were studied using Mössbauer spectroscopy and X-ray diffraction. The precipitation of the σ-FeCr phase was observed only in the samples with

Abstract X-ray diffraction analysis, scanning electron microscopy, and atomic force microscopy are used to study the phase composition, texture, and peculiarities of the morphology of R–Fe–B (R = Nd, Pr, Dy) alloys prepared by strip-casting technology. Along with the traditional structural components of the alloys, namely, areas characterized by randomly oriented fine grains of the main magnetic phase

Abstract—This critical review considers the fundamental concept, methods of obtaining, stability, and properties of a new class of materials—high-entropy alloys and compounds. An analysis of factors that determine the structure and stability of multicomponent disordered solid solutions has been carried out. Particular attention has been given to results obtained since 2017. The concept of temperature

Abstract A method of universal thermomagnetic treatment forming a pairwise opposite exchange bias in spin valves, which are sensor elements of a Wheatstone bridge, has been developed. The method is based on the formation of two magnetic phases in a spin valve upon the transition of a synthetic antiferromagnet into a spin-flop state. Thermomagnetic treatment in a two-phase state leads to the formation

Abstract The inhomogeneous magnetic state arising from isothermal aging of the rapidly quenched U–6Nb alloy (6.3 wt % or 14 at % niobium) was studied for the first time using nuclear magnetic resonance of the 93Nb nucleus. In the process of phase transformation during isothermal annealing at Тan = 500°C, the fraction of niobium atoms in the bulk of the alloy increases in regions with a magnetic susceptibility

Abstract This work has determined the peculiarities of structure and phase transformations at various initial temperatures (–129…548°С) and high deformation rates (448–530 m/s) of shock-wave loading in the austenitic nitrogen-containing steel KH20N6G11M2AFB (0.4N–20Сr–6Ni–11Mn–2Mo–V–Nb). The cyclic γ → ε → γ transformation is observed in the course of shock-wave loading at 20–203°С, which causes the

Abstract— The effect of the new combined rolling–pressing technique of plastic deformation on the structure and mechanical properties of copper has been investigated in this work. The deformation was performed at room temperature and there were three cycles. Rolling–pressing technique was shown to significantly refine the structure of the commercial-purity copper. The strength of the copper workpieces

Abstract The article discusses changes in the structure of Al–Mg–Si cast alloys after their additional alloying with lithium. To predict and explain the phase transformations in the studied alloys, phase diagrams were calculated using Thermo-Calc software. Thermo-Calc results are in good agreement with microstructure analysis. The morphology and chemical composition of the intermetallic phases were

Abstract— This work studies the structure and texture evolution in the 03Kh19N10 corrosion-resistant metastable austenitic steel (0.05C–18.2Cr–8.8Ni–1.65Mn–0.43Si–0.05P–0.04S wt %, and Fe for balance) during cold rolling, which results in twinning and martensitic transformation. The strain-induced martensite nucleates heterogeneously in the microshear bands and at their intersections. The fraction

Abstract—The review presents the original experimental data on the structure formation and properties of titanium, aluminum, copper, and their alloys upon intense deformation and shock-wave conditions. The main volume of the article is devoted to the production of the submicrocrystalline and nanocrystalline non-ferrous metals and alloys by dynamic channel-angular pressing. The optimal regimes of DCAP

Abstract Tribological tests of a hybrid composite (Al–12Si)–40Sn prepared by sintering mixtures of powders of silumin and pure tin were carried out using the pin-on-disk scheme. It has been established that an increase in the sliding velocity decreases the wear intensity of the composite upon dry friction, while an increase of the load leads to the opposite result. The data obtained indicate that the

Abstract A thermodynamic approach to the description of single- and multistage crystallization of iron- and aluminum-based amorphous alloys is suggested in this work. The adequacy of theoretical calculation of the volume fraction of the crystalline phase to experimental data is demonstrated for the case of precipitation of one or several phases in disordered systems. The parameters of the model depend

Abstract The structure and texture in recrystallized sheets of nonoriented electrical steel rolled according to different modes have been studied in this work. It has been shown that a decrease in the degree of deformation upon the final rolling leads to an increase in the ratio of the volume fractions of orientations that are favorable and unfavorable for the formation of optimal magnetic properties

Abstract A model of the final stage of nonstationary swelling has been developed to predict the residual life of fast neutron fuel elements by the criterion of achieving a swelling of 15%. A criterion for achieving this stage is formulated, using the shape of the histogram of the void size distribution. A set of characteristics of radiation porosity, sufficient for a quantitative description of the

Abstract Spin valves comprising a synthetic antiferromagnet and a CoFe/Dy/CoFe structure in the pinned layer were prepared by magnetron sputtering. It is shown that the Dy layer is characterized by crystallites, the [0002] direction of which is perpendicular to the film plane; a part of nanostructure, in which the spin-dependent electron scattering occurs, is characterized by smooth interfaces. Variations

Abstract The electronic structure of the Mn2CrAl Heusler alloy is calculated and its optical properties are studied in this work. The anomalous behavior of the optical properties of the alloy in the IR region of spectrum, namely, the absence of the contribution of intraband absorption and the low level of interband absorption, were found. Such peculiarities of the optical spectrum indicate the existence

Abstract Dynamic recrystallization (DR) of austenite of a medium-carbon steel microalloyed with titanium, niobium, vanadium, and boron has been studied in the course of deformation treatment in the temperature range of 850–1180°C using strain rates of 1–100 s–1. It has been established that the threshold deformation corresponding to the onset of the DR increases in a regular way with increasing strain

Abstract The influence of boron on the structure and on the mechanical and tribological properties of protective coatings of the Cr–Al–Ti–N alloys obtained by magnetron sputtering in a closed unbalanced magnetic field using segmented planar ceramic SHS targets has been studied. The obtained coatings were examined using glow discharge optical emission spectroscopy, scanning electronic microscopy, X-ray

Abstract The influence of the temperature, applied stress, degree of creep deformation, and aging time on the formation of Z-phase (CrVN) particles in 9% Cr 10Kh9K3V2MFBR martensitic steel at temperatures of 650 and 675°С upon long aging is studied in this work. The particles with a chemical composition determined by energy dispersive spectrometry as 50% (Cr + Fe) and 50% (V + Nb) are detected and

Abstract The structure and the mechanical and electrical properties of composites with 7 and 49 magnesium fibers in the copper matrix are studied in this work. It was found that the strength of a deformed composite wire with the maximum volume fraction of Cu/Mg interfaces exceeds the theoretical estimate and the strength of pure copper. It is shown that deformation-induced formation of high-strength

Abstract Hysteresis of the electric polarization of a two-layer exchange-coupled ferromagnetic film whose layers have the easy-plane and easy-axis anisotropy upon magnetization reversal is studied numerically. The magnetization reversal was carried out by a magnetic field perpendicular to the film plane from the saturation state along the easy magnetization axis. The dependences of the average electric

Abstract The microstructural changes on the surface of the samples of a binary brass and of brasses alloyed with iron and manganese or aluminum, taken place in the process of superplastic deformation at 550°C at a constant strain rate of 1 × 10–3 s–1 have been analyzed in this work. The contributions of the intergranular and intragranular deformation to the total elongation have been determined. It

Abstract The anticommutative Green’s functions and energy spectra of fullerene С28 and endohedral fullerene Zr@C28 with symmetry groups Td were obtained in the analytical form within the Hubbard model in the mean-field approximation. Group theory methods were used to categorize energy states and identify nonforbidden transitions in the energy spectra of С28 and Zr@C28 molecules with symmetry groups

Abstract The recrystallization process in copper subjected to high-rate compression deformation by collapsing a massive cylindrical shell into a cylinder has been studied in this work. Recrystallization occurs in two stages due to the peculiarities of the deformation structure. At the first low-temperature stage, regions with deformation-induced highly-misoriented (over 15 degrees) grains are recrystallized

Abstract The influence of ytterbium addition on the phase composition, strengthening upon annealing before and after rolling, and on the electrical conductivity and mechanical properties of the Al–0.2% Y–0.2Sc alloy has been investigated in this work. A dispersed eutectic, in which particles of an intermetallic phase with a size of 100–250 nm are enriched in yttrium and ytterbium, has been revealed

Abstract The fine structure of YBa2Cu3Oy single crystals with a different oxygen content subjected to a low-temperature hydrogenation have been investigated by transmission electron microscopy. It has been shown that as a result of the action of hydrogen at T = 150°С, a partial reduction of copper occurs, accompanied by the precipitation of Cu crystallites of ~100 nm in size and the formation of various

Abstract The effect of multidirectional forging on the evolution of the grain structure and the parameters of secondary-phase particles in the aluminum–magnesium alloy (Russian grade 1565ch) has been investigated using scanning and transmission electron microscopy. The multidirectional forging was performed at 200, 350, and 500°C to a total strain of 12. Five multidirectional forging cycles (cumulative

Abstract The interaction of the ribbon surface with acetone and its effect on the magnetic characteristics of ribbon are studied in this work using the example of soft magnetic Co-based AMAG-172 (Co–Ni–Fe–Cr–Mn–Si–B) amorphous alloy. The studies show the different effect of acetone treatment of ribbon on the magnetization distribution and magnetic permeability of material in states differing in the

Abstract The state of the surface and structure of the diffusion boride coating on the substrate of die steel have been studied after thermal cycling under a constant load of 193 N in hydrogen, nitrogen, and air atmospheres. It is shown that the degradation of boride coating in air occurs due to the development of oxidative processes beneath the coating at the boundary with the steel substrate. In

Abstract The spin-polarized electronic structure, magnetic moments, and spectra of optical conductivity of the ternary ErSn1.1Ge0.9 and TmSn1.1Ge0.9 compounds have been calculated within the GGA+U method, taking into account strong electron correlations in the 4f-shell of Er and Tm, as well as non-stoichiometry of compositions. The calculation results pointed to antiferromagnetic ordering for both

Abstract The nuclear transmutation effects in zirconium alloys are analyzed in this work. The molybdenum content in zirconium alloys of various compositions are numerically estimated under irradiation in research (SM-3) and power (WWER-1000) nuclear reactors. The dynamics of molybdenum accumulation under irradiation in the SM-3 reactor and subsequent one-year aging of samples is estimated in the Zr–1%

Abstract The deformation structure in copper that forms upon the convergence of a massive cylindrical shell into a cylinder is studied in this work. The shell in the deformation zone was subjected to high-speed deformation (~104 1/s) with large values of true strain (e varied from 0.8 to 2.0). It is shown that two types of structures were formed under deformation: regions containing disperse grains

Abstract This paper presents the mechanical, friction and magnetic properties of the Fe–P binary and Fe–P–Si ternary alloys produced by spark plasma sintering (SPS). The effects of the alloying elements P and Si on the friction, toughness performance, and magnetic properties of their alloys were systematically investigated. The results indicate that toughness performance and magnetic properties are

Abstract Peculiarities of the structure, magnetic properties, and temperature dependence of magnetoimpedance effect of a Fe20Co6Ni74/Cu98Be2 composite wire with the induced axial magnetic anisotropy are studied in this work. The increase in the temperature in a range from 150 to 450 K is shown to lead to an increase in the magnetoimpedance effect. To explain the experimental results, a model is proposed

Abstract The texture of niobium in composite Nb3Sn superconductors prepared by internal-tin-source and bronze techniques, and in a subelement, which is required for fabricating the composite using the internal-tin-source technique, is studied in this work. It is shown that prior to the reaction heat treatment, the structural components of Nb have the (110) drawing texture; after the reaction heat treatment

Abstract It is demonstrated in this work that the quantization of transverse motion of electrons in metal nanowires gives rise to transparency windows in the region of quasiclassical collisionless wave damping and makes the existence of excitations of a new type (quantum waves) possible in such systems.

Abstract The evolution of the microstructure and mechanical properties of quasibinary Al–6.5Cu–2.3Y and Al–6Cu–4.05Er alloys during homogenization and subsequent thermomechanical treatment has been studied in this work. The Cu concentration in the aluminum solid solution increases during homogenization before quenching owing to the dissolution of a nonequilibrium excess of phases of crystallization

Abstract Phase diagrams of the binary titanium, zirconium, and hafnium alloys with transition metals are analyzed in this work. The stabilizing effect of a d metal on the β phase is shown to depend on the position of the metal in the Periodic Table. The stabilizing effect in titanium alloys increases as the Group number of alloying element increases; the value of the effect is found to vary in accordance

This work proposes a new fractal model of a complex near-surface domain structure that assembles itself in highly anisotropic uniaxial single crystals, and which is based on a previously unknown modification of the Sierpinski carpet. The simulation algorithm is described and an example of its application is given.

Abstract The regularities of the formation of the magnetic structure near the systems of Bloch–Néel domain walls realized in the presence of an external magnetic field have been studied using the example of thin Fe0.25Ni0.75 films. It has been established that when the film is magnetized along the easy axis (EA), a stable quasi-closed distribution of magnetization (a blocked domain structure) is formed

Abstract The effect of impurities on the phase composition and properties of a wrought alloy of the Al–Cu–Er system has been investigated in this work. According to the results of the scanning electron microscopy and X-ray diffraction analysis, Al8Cu4Er, Al3Er, and Al3Er2Si2 particles of phases of crystallization origin are present in the structure of the alloy. After annealing at 605°C, the Al8Cu4Er

Abstract It is shown that initial treatment (quenching or annealing) has a significant effect on the evolution of the structure of hafnium bronze upon dynamic channel-angular pressing (DCAP). Upon annealing, hafnium becomes bound into particles of the intermetallic compound Cu5Hf, and the annealed samples are only insignificantly strengthened upon DCAP. Upon quenching, Hf remains in the solid solution

Abstract This article presents the results of experimental studies of the effect of proximity of a ferromagnetic dielectric with in-plane magnetization (Y3Fe5O12) on the superconducting transition in planar hybrid Y3Fe5O12/Nb and Y3Fe5O12/Al structures. The temperature dependence of the superconductor resistance changes due to the proximity of the magnetic dielectric: the superconducting transition

Abstract A system containing four alternating ferromagnetic and superconducting layers (F1/S1/F2/S2) is examined in this work. The state of this contact may be controlled by an external magnetic field. The critical temperature of the superconducting transition and the Josephson current are calculated theoretically at different thicknesses and collinear orientations of magnetizations of ferromagnetic

Abstract This work studies the behavior of magnetic skyrmions forming on columnar defects of potential well type in uniaxial ferromagnetic films in a magnetic field. It is shown that their structure, which is characterized by three sections of magnetic moment rotation, undergoes a series of transformations in a magnetic field. Critical fields for the restructuring of their structure, which substantially

Abstract The effects of three activating fluxes, SiO2, TiO2, and MoO3, in tungsten inert gas (TIG) welding process on penetration, morphology, and mechanical properties of weld joint were investigated by bead on plate welding on 2219 aluminum alloy. Experimental results showed that a noticeable increase in the weld penetration and depth to with ratio was obtained by using activating fluxes. Among all

Abstract The formation of nanoscale layers on the VT6 titanium alloy surface by ion-beam mixing of carbon with the N+ ion implantation is investigated in this work. Ion-beam mixing in the transition layer of a film–carbon system on the VT6 alloy surface has been found to provide conditions for the formation of titanium carbides and nitrides. The thin surface layer (~10–20 nm) of the samples after both

Abstract The effect of multidirectional forging on the grain structure and parameters of secondary-phase particles in the Al–4.8Mg–1.2Mn–0.1Cr alloy has been investigated using the methods of the scanning and transmission electron microscopy. The multidirectional forging performed at a temperature of 350°C to a cumulative strain of 10.5 has resulted in a 1.5 decrease in average particle sizes of the

Abstract—Phase transitions in the antiferromagnetic Heisenberg model on the body-centered cubic lattice were studied using the replica algorithm of the Monte Carlo method, taking into account the interactions between the first and second neighbors. The investigations were performed for the ratio of the value of the exchange interactions between the nearest and second neighbors in the range 0.0 ≤ r

Abstract In the present work, dependences of lamellar spacing (λ), microhardness (HV), and ultimate tensile strength (σUTS) on growth rate (V) were investigated in the Al–Cu–Ti (Al–33 wt % Cu–0.1 wt % Ti) eutectic alloy. For these purposes, the Al–Cu–Ti eutectic alloy was solidified at a constant temperature gradient of 6.45 K mm–1 with a wide range of growth rates, from 8.58 to 2038.65 µm/s. Then

Abstract Phase transitions in multiferroics with spatially modulated structures as ground states are studied in this work. The key physical mechanisms needed to implement modulated states of various kinds (cycloidal and helicoidal magnetic phases) and the conditions of phase transitions within modulated states are discussed. The domain of physical parameters where the ground state of the spin cycloid

Abstract The structure, phase composition, and local chemical composition of half-finished products (rods) made from Ti–Al–Mo–Zr–Si- and Ti–Al–Mo–Zr–Sn–Si-based alloys additionally microalloyed with 0.4 wt % gadolinium have been studied in this work. The structure of the rod made from the Gd-alloyed Ti–Al–Mo–Zr–Si composition was found to be characterized by the presence of Gd2O3 gadolinium oxide particles