bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetic and elastic oscillations in manganese-zinc spinel crystal in the region of spin reorientation
Authors: Kotov L. N. , Severin P. A. , Vlasov V. S. , Mironov V. V.
Published: April 2024

The formula for the magnetic dissipation parameter of ferrimagnetic crystals depending on the constant magnetic field and the anisotropy field was obtained. It was shown that in the region of magnetic reorientation in a manganese-zinc spinel crystal, magnetic and elastic vibrations of infinitely small amplitude and low frequency are excited, which are characterized by giant damping in a wide temperature range.
Pinning of vortices during the passage of turbulent magnetization reversal waves in antidot films with through and non-through holes
Authors: Zverev V. V.
Published: April 2024

Micromagnetic modeling of the process of magnetization reversal in films with antidot arrays, initiated by a moving domain wall, is performed. Under certain conditions, a narrow magnetization reversal zone appears, filled with vortex structures (turbulent wave). Changes in speed, temporary or final stops of the wave are observed. The existence of a connection between the features of wave motion and the structure of the vortex zone is shown.
Effect of hydrogenation on the structure and magnetic properties of Tb(Fe,Co)11Ti compounds
Authors: Makurenkova A. A. , Zhelezny M. V. , Pankratov N. Y. , Kozlyakova E. S. , Tereshina I. S. , Nikitin S. A.
Published: April 2024

The effect of hydrogenation on the structure and magnetic properties of TbFe11– xCoxTi compounds with different cobalt content (x = 0, 3, 4, and 5) has been studied. An X-ray diffraction  phase analysis was carried out and the parameters of the crystal structure of hydrides were determined. It is shown that hydrogenation leads to an isotropic increase in the unit cell volume. The experimental field and temperature dependence of the magnetization of single crystals hydride are studied in magnetic fields up to 90 kOe in the temperature range 5–300 K. The constants of magnetocrystalline anisotropy are determined.
Investigation of magnetic anisotropy effects in trilayer metal nanostructures based on iron film
Authors: Makeev M. Yu. , Mamonova M. V.
Published: April 2024

Within the framework of the spin density functional theory, the energy and magnetic properties of Fe/Cr/Fe, Fe/Pt/Fe systems were studied using the VASP software package. Calculations of the dependence of the total energy on the angle of direction of the magnetic moment of atoms showed the advantage of perpendicular anisotropy for Fe/Cr/Fe for all considered Fe film thicknesses and surface orientations. For Fe/Pt/Fe, a more complex dependence is observed, but with an increase in the iron film thickness, easy-plane anisotropy prevails.
Negative anisotropy in Ni–Fe films
Authors: Savin P. A. , Adanakova O. A. , Lepalovskij V. N. , Kudyukov E. V. , Vas’kovskiy V. O.
Published: April 2024

Fe–Ni films were obtained in which the effect of “negative anisotropy” is observed. This effect consists in the formation of easy magnetization axis perpendicular to the deposition field. A model based on negative magnetostriction, and inhomogeneous stresses is tested. The model parameters were varied by applying additional stresses to the film. The effect of additional stresses is analyzed by changing the shape of the R–H curves. It is shown that changes in anisotropy occur in accordance with the model.
Magnetization reversal of the longitudinally magnetized film with cubic anisotropy by magnetic pulses
Authors: Shaporov V. N. , Kotov L. N. , Vlasov V. S.
Published: April 2024

Magnetization reversal diagrams are constructed for a longitudinally magnetized film with the parameters of yttrium iron garnet doped with cobalt. The film is excited by nanosecond magnetic field pulses with an amplitude of up to 1000 Oe. It is shown that at a magnetizing field smaller than the anisotropy field, under the action of the pulse field, transitions between stable states, characterized by energy minima, occur.
Photoresistance of a film heterostructure Ba0.8Sr0.2TiO3/LaMnO3/Ba0.8Sr0.2TiO3/MgO
Authors: Chibirev A. O. , Leontyev A. V. , Salikhov T. M. , Mamin R. F.
Published: April 2024

An effect of illumination by ultrashort laser pulsed light at 514 nm on electrical resistance of Ba0.8Sr0.2TiO3/LaMnO3 heterostructure has been observed. In the temperature range below 175 K, illumination causes a reversible increase in the resistance. A time constant linked to the rate of resistance changes is about 30–50 s.
Conductivity of a film heterostructure Ba0.8Sr0.2TiO3/LaMnO3/Ba0.8Sr0.2TiO3
Authors: Chibirev A. O. , Leontyev A. V. , Bannikov M. I. , Mamin R. F.
Published: April 2024

The electrical resistance of Ba0.8Sr0.2TiO3/LaMnO3/Ba0.8Sr0.2TiO3 film heterostructures has been studied. It is shown that the resistance decreases significantly with a temperature below the maximum temperature of about 170 K. Thus, for such heterostructures, the effect of quasi-two-dimensional conductivity was discovered, but only at certain layer thicknesses.
Effect of oxygen vacancies on the electronic properties of the LaMnO3/BaTiO3 heterostructure
Authors: Gumarova I. I. , Mamin R. F.
Published: April 2024

For the LaMnO3/BaTiO3 heterostructure, the influence of the presence of oxygen vacancies located in different layers of the heterostructure on the structural, electronic, and magnetic properties was studied using ab initio calculations. It was found that the presence of vacancies in any layer of the heterostructure induces the appearance of interface conductivity concentrated within the atomic layer.
Obtaining and researching materials for suppressing external vibrations in the responsible nodes of synchrotron radiation accelerators
Authors: Gorbunov F. K. , Fadina A. A. , Nguyen T. V. A.
Published: April 2024

We show that the introduction of powders-modifiers into a polymer matrix in an amount of less than 1 wt % leads to an increase in the strength characteristics and resistance to cyclical loading with a force of 50–1600 N and a frequency of 2 Hz of more than 3 million cycles.
Flat-field correction on X-ray tomographic images using deep convolutional neural networks
Authors: Grigorev А. Yu. , Buzmakov А. V.
Published: April 2024

We proposed to use neural networks to solve the problem of flat-field correction. We described the process of selecting parameters of a deep convolutional neural network to solve the flat-field correction problem with the instability of an empty beam, describes the training of this network, and checks its operability on the generated data. The developed method was tested on data obtained both on laboratory X-ray sources and synchrotron sources.
Production of high-strength weakly conductive ceramics based on barium aluminate
Authors: Zhdanok A. A. , Berdnikova L. K. , Korotaeva Z. A. , Tolochko B. P. , Bulgakov V. V. , Mikhaylenko M. A.
Published: April 2024

Weakly conductive ceramics based on barium aluminate have been synthesized and investigated. When fired in an oxidizing medium monophase ceramics with a maximum compressive strength of 678.5 MPa and a density of 3.78 g/cm3 were obtained. The introduction of conductive additives into the composition makes it possible to increase the specific electrical conductivity of ceramics to 1.05 · 10–4 S/cm (at 300°C).
Conceptual design of the experimental section for measuring time resolved small angle X-ray scattering
Authors: Rubtsov I. A. , Zubavichus Ya. V. , Ten K. A. , Pruuel E. R. , Kashkarov A. O. , Kuper K. E. , Studennikov A. A. , Tolochko B. P. , Shekhtman L. I.
Published: April 2024

As part of development of the experimental beamline 1-3 “Fast Processes” of the 4+ generation synchrotron radiation source, a scheme for measuring time resolved small-angle X-ray scattering was worked out. Measuring time resolved small-angle X-ray scattering is extremely relevant today for studying the evolution of carbon particles during the detonation of energy materials, as well as for a number of other tasks.
Investigation of the conditions for the formation of the α2-phase in mechanocomposites of the Ti–Al system by synchrotron radiation methods
Authors: Sobachkin A. V. , Loginova M. V. , Sitnikov A. A. , Yakovlev V. I. , Filimonov V. Y. , Negodyaev A. Z. , Myasnikov A. Y. , Sharafutdinov M. R. , Popova A. A.
Published: April 2024

Synchrotron studies of the features of the dynamics of phase formation in a mechanically activated 3Ti + Al powder mixture during the implementation of high-temperature synthesis under conditions of volumetric ignition by induction heating are carried out. The effect of the time of preliminary mechanical activation treatment of the initial mixture (1, 3, 7 minutes) on the macrokinetic parameters of synthesis was experimentally investigated.
Investigation of the effect of modifying additives on the properties of copper obtained by casting
Authors: Tolochko B. P. , Zhdanok A. А. , Kuznetsov V. A. , Korotaeva Z. A. , Berdnikova L. K. , Stepanova N. V. , Mikhaylenko M. A.
Published: April 2024

The effect of additives containing chromium, zirconium, silicocalcium and carbon nanotubes on the physical-mechanical properties of copper obtained by casting is investigated. The tensile strength increased to 10.5%, Young’s modulus increased by 11.6–106.2%. The heat resistance of samples using SiCa increased by 1.9 times, Cu–Zr – by 1.5 times, with the use of nanotubes decreased by 1.2–1.8 times.
Electrodynamic system for powerful THz-band free-electron laser based on linear induction accelerator “LIU”: simulations and “cold” tests
Authors: Peskov N. Yu. , Аrzhannikov А. V. , Belousov V. I. , Ginzburg N. S. , Zaslavsky V. Yu. , Nikiforov D. А. , Oparina Yu. S. , Savilov А. V. , Sandalov Е. S. , Sinitsky S. L. , Sobolev D. I.
Published: April 2024

The current stage of development of powerful long-pulse free-electron laser (FEL) of the terahertz band carried out in the BINP RAS in collaboration with the IAP RAS based on the linear induction accelerator “LIU” with an energy of 5–10 MeV, a kA-level current, and a pulse duration of up to 200 ns is described. To ensure a stable narrow-band generation regime, the project proposes the use of two alternative types of the electrodynamic system: advanced Bragg resonators and quasi-optical Talbot-type resonators. We discussed design parameters of the FEL based on these resonators and results of their simulations under conditions of substantial oversize. Operability of resonators of the novel types was demonstrated in the “cold” electrodynamic tests.
Structure, physico-mechanical properties and piezoresponse of scaffolds based on polyhydroxybutyrate with composite magnetite/reduced graphene oxide filler
Authors: Shlapakova L. E. , Pryadko A. S. , Mukhortova Yu. R. , Wagner D. V. , Surmeneva M. A. , Surmenev R. A.
Published: April 2024

The influence of fiber diameter and addition of composite filler magnetite/reduced graphene oxide on the properties of electrospun scaffolds of poly(3-hydroxybutyrate) has been studied. The magnetic composite filler provides good magnetic properties and piezoresponse of the scaffolds, while changing the fiber diameter allows controlling the ductility, crystallinity, and surface electric potential.
Mangiferin-loaded nanofibers based on hyaluronic acid
Authors: Klimshina V. I. , Snetkov P. P. , Morozkina S. N. , Uspenskaya M. V.
Published: April 2024

The physical characteristics of water-organic spinning solutions based on hyaluronic acid with the addition of mangiferin were investigated. From these solutions by electrospinning, fibers were obtained and morphologically characterized, which can be recommended as regenerative coatings, as well as mangiferin delivery systems with transdermal transfer.
Fermi level pinning on the (110) oxidized surface of AIII-Sb semiconductors
Authors: Alekseev P. A. , Smirnov A. N. , Sharov V. A. , Borodin B. R. , Kunitsyna E. V.
Published: April 2024

Pinning of the Fermi level on the oxidized (110) surface of AIII-Sb semiconductors (GaSb, Ga0.78In0.22As0.18Sb0.82, Ga0.66Al0.34As0.025Sb0.975) was studied. It is shown that the Fermi level is pinned at 4.65 ± 0.1 eV from the vacuum level. The presence of Sb was shown for the photooxidized Ga0.78In0.22As0.18Sb0.82 and Ga0.66Al0.34As0.025Sb0.975 surfaces. The formation of Sb on the surface because of faster oxidation of group III elements results in pinning of the Fermi level at the same distance from the vacuum level in III-Sb compounds.
Investigation of the characteristics of supercapacitor electrodes based on doped silicon-carbon films
Authors: Bogush I. Yu. , Plugotarenko N. K.
Published: April 2024

Silicon-carbon films undoped and doped with manganese and nickel have been investigated by cyclic voltammetry, galvanostatic charge/discharge and impedance spectroscopy. The charge storage process in silicon-carbon films is determined to be predominantly capacitive in nature. The best specific capacitance retention is observed for electrode samples containing nickel.
The energy position of size quantization levels in multiple HgCdTe quantum wells
Authors: Mikhailov N. N. , Remesnik V. G. , Aleshkin V. Ya. , Dvoretsky S. A. , Uzhakov I. N. , Shvets V. A.
Published: April 2024

The energy position of size quantization levels size levels in the multiple Hg0.3Cd0.7Te/HgTe quantum wells grown by molecular beam epitaxy on (013)GaAs substrate has been studied. The experimental and calculated values of the energy position of three size quantization levels are obtained.
Self-sustaining conducting state and bipolar ionizing Gunn domains in pulse avalanche GaAs diodes
Authors: Rozhkov А. V. , Ivanov M. S. , Rodin P. B.
Published: April 2024

Domain instability in nonequilibrium electron-hole plasma leads to the formation of narrow moving regions of the ionizing electric field—collapsing Gunn domains. In pulse power electronics devices based on gallium arsenide, impact ionization in collapsing domains acts as an efficient mechanism for the generation of nonequilibrium carriers at low voltages and weak average electric fields.
Quantum-dimensional near-surface recombination of photocarriers in CdTe microcrystals
Authors: Selkin A. V. , Yuldashev N. Kh.
Published: April 2024

The low-temperature (T = 2 K) photoluminescence spectra of a p-CdTe/n-CdS film heterostructure containing CdTe microcrystals have been studied. In the spectral region above the intrinsic absorption edge of bulk CdTe, a dominant “superhot” radiation band was found. The band arises because of optical transitions of electrons from near-surface levels of the spatial quantization of a microcrystal to the valence band states.
GaN/AlGaN resonant Bragg structure
Authors: Ivanov A. A. , Chaldyshev V. V. , Zavarin E. E. , Sakharov A. V. , Lundin W. V. , Tsatsulnikov A. F.
Published: April 2024

Reflection spectra from a resonant Bragg structure with 30 GaN/AlGaN quantum wells have been measured at room temperature. Numerical modeling using the method of transfer matrices gave a quantitatively accurate fit of the experimental results. Defined radiative and non-radiative broadening parameters of the exciton in GaN/AlGaN quantum wells.
Terahertz radiation sources based on AlGaAs/GaAs superlattices
Authors: Dashkov A. S. , Gerchikov L. G. , Goray L. I. , Kharin N. Yu. , Sobolev M. S. , Khabibullin R. A. , Bouravleuv A. D.
Published: April 2024

We proposed several types of design of terahertz emitters based on the perfect AlGaAs/GaAs superlattices obtained by molecular-beam epitaxy. Transition energies, gain, and losses are calculated for the developed structures, which determined the design of the created experimental structures.
Effects of cosmic rays’ self-modulation on the galactic diffuse gamma-ray emission
Authors: Chernyshov D. O. , Ivlev A. V. , Kulik E. A.
Published: April 2024

We studied how the process of self-modulation of cosmic rays, occurring upon their penetration into dense molecular clouds, affects the total gamma-ray emission of the Galaxy. We estimated how the self-modulation modifies the emission from each individual cloud and integrate the results along the line of sight for a given area in the sky. Our calculations show that the self-modulation reduces the total intensity of gamma-ray emission below 1 GeV by about 10–30%. Even though the magnitude of the effect is not large, it still can substantially affect the background gamma-ray emission at low energies.
Average muon energies in inclined bundles according to NEVOD-DECOR data
Authors: Yurina E. A. , Barbashina N. S. , Bogdanov A. G. , Vorobev V. S. , Kindin V. V. , Kokoulin R. P. , Kompaniets K. G. , Konovalova A. Yu. , Mannocchi G. , Petrukhin A. A. , Trinchero G. , Khokhlov S. S. , Shutenko V. V. , Yashin I. I.
Published: April 2024

Results of measurements of the energy characteristics of muon bundles in inclined extensive air showers in the NEVOD-DECOR experiment are presented. Estimates of the average energy of muons in the bundles in the energy range of primary particles from 10 to 1000 PeV were obtained and compared with the calculated expected values for various assumptions about the composition of cosmic radiation and models of hadronic interactions. An excess of experimental values of the average muon energy in comparison with calculations for high local densities corresponding to energies of primary particles above 100 PeV was found.
Results of the track-like neutrino event reconstruction at the BAIKAL-GVD neutrino telescope
Authors: Avrorin A. V. , Avrorin A. D. , Aynutdinov V. M. , Allakhverdyan V. A. , Bardačová Z. , Belolaptikov I. A. , Borina I. V. , Budnev N. M. , Gafarov A. R. , Golubkov K. V. , Gorshkov N. S. , Gress T. I. , Dvornický R. , Dzhilkibaev Zh.-A. M. , Dik V. Ya. , Domogatsky G. V. , Doroshenko A. A. , Dyachok A. N. , Elzhov T. V. , Zaborov D. N. , Kebkal V. K. , Kebkal K. G. , Kozhin V. A. , Kolbin M. M. , Konischev K. V. , Korobchenko A. V. , Koshechkin A. P. , Kruglov M. V. , Kryukov M. K. , Kulepov V. F. , Malyshkin Yu. M. , Milenin M. B. , Mirgazov R. R. , Nazari V. , Naumov D. V. , Petukhov D. P. , Pliskovsky E. N. , Rozanov M. I. , Rushay V. D. , Ryabov E. V. , Safronov G. B. , Seitova D. , Sirenko A. E. , Skurikhin A. V. , Solovjev A. G. , Sorokovikov M. N. , Stromakov A. P. , Suvorova O. V. , Tabolenko V. A. , Tarashansky B. A. , Fajt L. , Khatun A. , Khramov E. V. , Shaybonov B. A. , Shelepov M. D. , Šimkovic F. , Štekl I. , Eckerová E. , Yablokova Y. V.
Published: April 2024

Baikal-GVD is a 1 km3 – scale neutrino telescope being constructed in Lake Baikal. Presently the sensitive volume of the detector constitutes about 0.5 km3. Muons being produced in muon and partly tau-neutrino interactions in the vicinity of the telescope ongoing through the W-boson exchange propagate at large distances in Lake water. Reconstructed muon trajectory provides the most precise probe of the neutrino direction attainable at large-volume neutrino telescopes. Angular resolution can be as good as 0.5° for muon tracks of sufficient length. The status of the data analysis in the muon channel at the Baikal-GVD is discussed.
Solar proton enhancements and Forbush decreases with the same sources
Authors: Belov A. V. , Shlyk N. S. , Abunina M. A. , Belova E. A. , Abunin A. A. , Papaioannou A.
Published: April 2024

The characteristics of Forbush decreases (FDs) and solar energetic particle (SEP) events driven by the same solar sources (i.e. coronal mass ejection and associated solar flare) are investigated. The part of the solar disk (E04–W35) was chosen in which most of the solar events lead both to an FD and SEP event at Earth. SEPs for different energies (E 10, 100 MeV, and ground level enhancements) and with different flux thresholds were considered independently. The obtained results were compared with the control group of solar events that had solar sources within the same longitudinal zone but did not lead to any SEPs. It is shown that coronal mass ejections (CMEs) followed by SEPs have a very high probability to create a large FD in the Earth’s orbit and further to cause a geomagnetic storm. It is also obtained that the accelerative and modulating efficiencies of such driving solar events are well correlated; this can be explained mostly by high solar wind speeds of the corresponding CMEs.
Characteristics of solar proton events during the periods of Sun’s magnetic field reversal in the last 6 solar cycles
Authors: Kalegaev V. V. , Ustinov K. A. , Podzolko M. V.
Published: April 2024

Characteristics of solar proton events during the periods of Sun’s magnetic field reversal in 19–24 solar activity cycles have been considered. In each of these solar cycles periods of time with duration of 8–12 months have been found, during which the number of solar events, total and maximal proton fluences were lower and the energy spectra were softer, than during the periods of equal duration before and after that. In most of the considered cycles the mentioned periods occurred after the cycle maximum or during the local “Gnevyshev minima”.
Efficiency of mechanisms for the formation of sporadic Forbush decreases
Authors: Petukhova A. S. , Petukhov I. S. , Petukhov S. I.
Published: April 2024

From the measurements of the neutron monitors world network in the period 1996–2018, 31 strong Forbush decreases (5%) were identified that satisfy the accepted event selection criterion. The superposed epoch analyses is used to determine the consistent spatial distributions of the solar wind parameters and the decrease in cosmic ray density. It has been established that the contributions of the formation mechanisms of the Forbush decrease differ greatly in two groups of events. The difference may be since the formation of the Forbush depression in one group occurs in the frontal part, and in the other group in the peripheral part of the disturbance.
Estimation of the neutron monitors’ effective energies based on the 27-day galactic cosmic rays variations
Authors: Siruk S. A. , Mayorov A. G. , Yulbarisov R. F.
Published: April 2024

We presented a new method of the neutron monitors’ (NM’s) effective energy estimation based on the 27‑day galactic cosmic rays (GCR) variations: using AMS-02 measurements we study rigidity dependance of 27-day variations’ amplitude and calculate the energy value so that the variability of the GCR particles at this energy is equal to that of the NM’s count rate. We examined how NM’s effective energy depends on the geomagnetic cutoff rigidity using data of several NM.
Azimuthal scanning of the atmosphere in a muon flux
Authors: Timakov S. S. , Petrukhin A. A.
Published: April 2024

A new approach to the analysis of the intensity of the muon flux from different azimuthal directions is considered, which makes it possible to detect waves in the atmosphere from large-scale atmospheric phenomena (fronts, thunderstorm cells).
The study of electronic kinetics of molecular nitrogen in the Titan’s middle atmosphere during the precipitation of cosmic rays
Authors: Kirillov A. S. , Werner R. , Guineva V.
Published: April 2024

The kinetics of the \({{{\text{A}}}^{3}}\Sigma _{u}^{ + },\) B3Πg, W3Δu, \({{{\text{B}}}^{{{\text{'}}3}}}\Sigma _{u}^{ - },\) and C3Πu triplet states of molecular nitrogen at the heights of the middle atmosphere of Titan during action of cosmic rays into the atmosphere has been studied. The calculations consider the intramolecular and intermolecular electron energy transfer during inelastic collisions of electronically excited molecular nitrogen with N2, CH4, and CO molecules. The interaction of electronically excited N2 molecules with molecules of acetylene C2H2 and ethylene C2H4 in the middle atmosphere of Titan at altitudes of 50–250 km has been studied. For the first time, the dominance of reactions with metastable molecular nitrogen N2(\({{{\text{A}}}^{3}}\Sigma _{u}^{ + }\)) in the formation of C2H and C2H3 radicals at these heights has been shown.
On the studies of the reactions 13C(γ, p), 14N(γ, 2p), and 14N(γ, 2) at the pulsed electron accelerator with measurements of (12B, 12N)-activity by ΔE-detector telescopes
Authors: Belyshev S. S. , Dzhilavyan L. Z. , Karev A. I. , Lapik A. M. , Polonski A. L. , Ponomarev V. N. , Rusakov A. V. , Turinge A. A.
Published: April 2024

The issues are considered for studying the yields of the reactions 13C(γ, p)12B, 14N(γ, 2p)12B, and 14N(γ, 2n)12N with measuring (12B, 12N)-activity by telescopes of ΔE-detectors in time between electron accelerator pulses. For the chosen radiators and targets, the fluxes, and spectra of irradiating bremsstrahlung γ-quanta are found. The influence of the parameters of targets and telescopes of ΔE-detectors on production of (12B, 12N)-nuclei and registration of their decay is estimated.
First tests on the gas-filled separator GRAND for the Super Heavy Element Factory at the Flerov Laboratory of Nuclear Reactions in JINR
Authors: Kuznetsova A. A.
Published: April 2024

The gas-filled separator GRAND is experimental setup created for Super Heavy Element Factory of the FLNR (JINR). It is intended for experiments of the synthesis of super heavy elements and for study of their physical and chemical properties. The ion-optical parameters of the setup were checked using α-particle tracing from standard 226Ra and 244Cm sources. The complete fusion reaction of 208Pb(48Ca, xn)256No* was used for estimation of the transmission efficiency of recoil nuclei in the separator.
Simulation of charmed particle production in Geant4
Authors: Galoyan A. S. , Grichine V. M. , Ribon A. , Uzhinsky V. V.
Published: April 2024

It is expected that charmed particles will be copiously produced at Future Circular Collider (FCC). Due to relatively large lifetime of the particles, it will be needed to account their interactions with surrounded materials and detector’s materials. To satisfy the requirements, charmed particle production in soft interactions has been implemented in QGS and FTF models of the Geant4 package. Some details of the implementations are considered.
Soliton solutions of the equations of hydrodynamics in describing collisions and oscillations of atomic nuclei
Authors: D’yachenko A. T. , Mitropolsky I. A.
Published: April 2024

The hydrodynamic approach was used to find an analytical solution of the hydrodynamic equations in the soliton approximation for layer collisions in the one- and two-dimensional cases. The compression stage, the decompression stage, and the expansion stage are considered within the framework of a single formula for layers with energies on the order of ten MeV per nucleon. Our generalization to the two-dimensional case leads to the idea of the formation of a rarefied bubble region at the stage of expansion. The approach can be used in other fields for calculations of the nonlinear dynamics of oscillations of complex systems.
Theoretical study of antihydrogen formation reactions in the three body \({{e}^{ + }}{{e}^{ - }}\bar {p}\) system via Faddeev–Merkuriev equations in total orbital momentum representation
Authors: Gradusov V. A. , Roudnev V. A. , Yarevsky E. A. , Yakovlev S. L.
Published: April 2024

The results of calculations of low-energy reaction in the three body \({{e}^{ + }}{{e}^{ - }}\bar {p}\) system with the emphasis on the process of the antihydrogen formation from the ground and excited states of the positronium are presented. This reaction is important for some of the current antimatter experiments. The multi-channel scattering calculations are based on a new highly efficient method of solving the Faddeev–Merkuriev equations in total orbital momentum representation. We discuss the effects that originate from the long-range dipole interaction between the excited atom and the spectator particle.
Astrophysical S-factor in a square-well potential model
Authors: Torilov S. Yu. , Maltsev N. A. , Zherebchevsky V. I.
Published: April 2024

The astrophysical S-factor for the fusion of light nuclei, important for stellar nucleosynthesis reactions was analyzed within the framework of a model with a square-well potential. Using this model, one can obtain a good description of the experimental data in the sub-barrier energy region for the even-even nuclei fusion reactions in a mass number range of 12 ≤ А ≤ 28. Also, the functional dependencies for the systematics of potential parameters were obtained.
Multiorder and structural mechanism of the LiRh2O4 tetragonal phase formation
Authors: Talanov M. V. , Shirokov V. B. , Talanov V. M. , Aulov M. S.
Published: April 2024

The results of the group-theoretical analysis of phase transitions in the LiRh2O4 are presented. It is found that the critical irreducible representation inducing phase transitions and multiorder in this substance is the eight-dimensional representation \(~{{k}_{{11}}}{{{\text{\tau }}}_{5}} + {{k}_{{10}}}{{{\text{\tau }}}_{2}}\). It is shown that the multiorder and the structural mechanism of formation of the tetragonal phase of lithium rhodonite are related to the displacements of oxygen atoms, the tilts of the [RhO]6 octahedra, and the ordering of the rhodium t2g orbitals.
The size effects on phase transitions in ferroics
Authors: Nechaev V. N. , Shuba A. V.
Published: April 2024

The features of phase transitions temperature behavior in nanosized ferroics are discussed in the framework of phenomenological theories. It is shown that in the case of second-order transitions to both the commensurate and incommensurate phases, the critical temperature can shift significantly depending on the characteristic dimensions of the sample and the properties of the surface. In materials with the first-order phase transition, size effects have a significant influence on the nucleation process, leading to the transition temperature shift or even the phase transition type change have been determined.
Effect of Nb2O5 on phase formation, magnetic-dielectric and magnetic-resistive correlation of solid solutions Bi0.5La0.5MnO3 ± σ
Authors: Volkov D. V. , Nazarenko A. V. , Shilkina L. A. , Verbenko I. A.
Published: April 2024

We presented the results of the study of solid solutions based on Bi0.5La0.5MnO3 ± σ modified Nb2O5. Structural, microstructural, magnetic-dielectric and magnetic-resistive correlation in a wide range of frequencies and temperatures are investigated. Correlations between the structure of ceramics, their dielectric properties and behavior in a magnetic field are established.
Dielectric properties of mixed nanocomposites BaTiO3–SrTiO3
Authors: Al Jaafari F. M. D. , Korotkov L. N. , Tolstykh N. A. , Emelianov N. A. , Pankova M. A. , Popov S. V.
Published: April 2024

The dielectric properties of (1 – x)BaTiO3–xSrTiO3 (x = 0.0; 0.25; 0.50; 0.75 and 1.00) mixed nanocomposites, obtained by sintering the initial components at a temperature of 1273 K for 5 hours, have been studied within the temperature range of 100–500 K. X-ray analysis, performed at room temperature, showed that the composites are formed by BaTiO3 (P4mm) and SrTiO3 (Pm-3m) crystallites and do not contain Ba(1 – х)SrхTiO3 solid solutions. A decrease in the temperatures of the Amm2 → P4mm → Pm-3m phase transitions in barium titanate particles with an increase in the SrTiO3 concentration in the composite was found.
Investigation of the resistance behavior of LaMnO3/Bi4Ti3O12/Ba0.4Sr0.6TiO3/MgO film heterostructures
Authors: Pavlov D. P. , Chibirev A. O. , Salikhov T. M. , Mamin R. F.
Published: April 2024

The temperature behavior of the LaMnO3/Bi4Ti3O12/Ba0.4Sr0.6TiO3/MgO heterostructure resistance was studied. Within the temperature range of 120–180 K, an anomalous region with two resistance maxima was found. Below 120 K, a transition to a metallic character of conductivity occurs. It was revealed the significant increase of the heterostructure resistance under the influence the green light radiation.
Ceramic matrix piezocomposites: microstructural features and dielectric properties
Authors: Rybyanets A. N. , Nasedkin A. V. , Shvetsova N. A. , Petrova E. I. , Lugovaya M. A. , Shvetsov I. A.
Published: April 2024

A new method for the fabrication of ceramic-matrix piezocomposites (CMC) ceramics/ceramics has been developed. Samples of piezoactive PZT/PZT composites with a mass concentration of components from 0 to 50% have been obtained. The study of microstructural and gravimetric features, as well as the dielectric properties of CMC, has been carried out. Finite element modeling and experimental study of CMC properties in the region of dielectric percolation transition have been performed. It is shown that the developed method for manufacturing CMC provides the formation of microhomogeneous composite structures with a uniform distribution of ceramic filler particles in a microporous piezoceramic matrix without the formation of transition regions and additional crystalline phases.
The effect of a static magnetic field on the low-frequency dielectric permittivity of nominally pure and Co2+ ions doped triglycine sulfate crystals
Authors: Golitsyna O. M. , Drozhdin S. N.
Published: April 2024

The effect of a weak static magnetic field on the low-frequency dielectric permittivity of the crystals of nominally pure triglycine sulfate (TGS): and TGS containing cobalt ions (TGS + Co2+) is investigated. In TGS, the magnetic effect is essentially anisotropic: it is completely absent when the vectors \(\vec {B}\) and \({{\vec {P}}_{{\text{s}}}}\) are collinear and is most pronounced when \(\vec {B} \bot {{\vec {P}}_{{\text{s}}}}\) and the magnetic field is oriented along the crystallophysical axis \(\vec {a}\). In TGS + Co2+ magnetic effect is noticeably stronger than in TGS, but practically does not depend on the mutual orientation of vectors \(\vec {B}\) and \({{\vec {P}}_{{\text{s}}}}\).
Temperature dependences of permittivity and conductivity of sodium-lithium niobate ceramics
Authors: Malysheva N. E. , Malyshkina О. V.
Published: April 2024

As a result of comparative studies of the electric and dielectric properties of sodium-lithium niobate ceramics with a percentage of Li equal to 10 and 40 mass %, it was found that both materials have a hopping conduction mechanism. At frequencies from 500 Hz to 100 kHz, thermal ionic polarization predominates. In the low-frequency region, migratory polarization predominates. The revealed difference in the temperature behavior of the complex conductivity of the studied samples made it possible to explain the presence of ferroelectric properties in the sample with 10% Li and their absence in the sample with 40% Li.
Dielectric and thermal properties of potassium nitrate–carbon nanotubes composites
Authors: Milinskiy A. Yu. , Chernechkin I. A. , Baryshnikov S. V.
Published: April 2024

The results of a study of composites obtained by mixing potassium nitrate and carbon nanotubes are discussed. It has been shown that the effects of the interaction of the composite components lead to the expansion of the temperature range of the existence of the ferroelectric phase of potassium nitrate from 22 K for KNO3 to 38 K for a composite with a carbon nanotubes content of 2.0 vol % percent.
Structure and electrical properties of (Mg/ZrO2)52 multilayer nanostructures
Authors: Stognei O. V. , Smirnov A. N. , Sitnikov A. V. , Volochaev M. N.
Published: April 2024

Multilayer (Mg/ZrO2)52 nanostructures differing from each other in the thickness of the Mg layers and the same thickness of the ZrO2 layers were obtained by ion-beam sputtering of two targets in an argon. The thickness of one bilayer (Mg + ZrO2) varies from 3.6 to 8.5 nm. It was found that the use of zirconium dioxide prevented the oxidation of the magnesium phase. The presence of an electric percolation threshold was found when the morphology of magnesium layers changes (transition from discrete to continuous) as a result of an increase in the bilayer thickness. A change of the electrotransport mechanism in the (Mg/ZrO2)52 multilayer nanostructures upon passing through the percolation threshold has been established.
Fractal analysis of magneto-optical visualization of the remagnetization of a permanent magnet in a pulsed field
Authors: Zigert A. D. , Kuz’min N. B. , Sdobnyakov N. Yu. , Ivanova A. I. , Dunaeva G. G. , Semenova E. M.
Published: April 2024

The results of fractal analysis of images of the surface of a permanent magnet KS37, obtained by the method of the polar Kerr effect using an indicator bismuth-containing ferrite-garnet film after magnetization reversal by a pulsed field of 0.1–1.5 T, are presented. The obtained dependences of the residual magnetization on the magnitude of the external pulsed field are compared with the fractal dimension of the magneto-optical images of the magnet surface after exposure to the pulsed field. It is shown that the maximum value of the fractal dimension corresponds to the demagnetized state of the magnet.
Characterization of vertically aligned carbon nanotubes by piezoresponse force microscopy
Authors: Il’ina M. V. , Soboleva O. I. , Polyvianova M. R. , Selivanova D. I. , Khubezhov S. A. , Il’in O. I.
Published: April 2024

The piezoelectric properties of vertically aligned carbon nanotubes (CNTs) are characterized using the piezoresponse force microscopy method. Dependence of piezoelectric properties on the nitrogen concentration is established. It is shown that CNTs have predominantly longitudinal polarization due to the direction of the dipole moment in the bamboo-like “bridges”. It has been established that a decrease in the growth temperature from 690 to 645°С leads to an increase in the piezoelectric strain coefficient of CNTs from 4.5 to 21.2 pm ⋅ V–1. The obtained results can be used in the development of energy-efficient nanopiezotronic devices.
Electron-microscopic study of phase transformations in 316L austenitic steel manufactured by laser 3D printing
Authors: Kazantseva N. V. , Vinogradova N. I. , Koemets Yu. N. , Ezhov I. V. , Davidov D. I.
Published: April 2024

We studied the structure and phases in porous samples of 316L austenitic steel manufactured by laser 3D printing. Transmission electron microscopy revealed the presence of residual δ-ferrite along with austenite in the sample. A high density of dislocations is also observed in the sample. EBSD analysis revealed a lack of texture.
Carbon nanoparticle identification using transmission electron microscopy methods in biological samples
Authors: Masyutin A. G. , Tarasova E. K. , Onishchenko G. E. , Erokhina M. V.
Published: April 2024

Carbon nanoparticles are a common type of nanoparticles, the identification of which in biological samples is associated with great difficulties. It is demonstrated that the use of standard transmission electron microscopy in combination with the electron diffraction method is a reliable and relevant tool for the carbon nanoparticles identification in biological samples.
Study of the effect of cation substitution on the formation of microcracks in Ni-rich layered oxides
Authors: Moiseev I. A. , Golubnichiy А. А. , Pavlova А. P. , Abakumov А. M.
Published: April 2024

The formation of microcracks in agglomerated particles of positive electrode (cathode) material based on Ni-enriched layered oxide LiNi0.6Mn0.2Co0.2O2 has been studied using transmission electron microscopy. The influence of magnesium cations as a doping additive on the stability of the material to the accumulation of structural defects and the formation of cracks during long-term galvanostatic cycling is demonstrated, and a mechanism for stress relaxation is proposed.
Electron beam stimulated luminescence of helium ion irradiated hexagonal boron nitride
Authors: Petrov Yu. V. , Vyvenko O. F. , Gogina O. A. , Sharov T. V. , Kovalchuk S. , Bolotin K.
Published: April 2024

The impact of the irradiation with focused helium ion beam and electron beam on the cathodoluminescence (CL) of hexagonal boron nitride was investigated. It was shown that the irradiation with helium ions resulted in a decrease of the intensity of CL in the region 200–700 nm. Subsequent irradiation with electrons results in an increase of the intensity of 2 eV CL band comparing with its intensity in pristine material.
Degradation of the surface of melamine formaldehyde particle in dusty plasma in neon and krypton
Authors: Polishchuk V. A. , Dzlieva E. S. , Ermolenko M. A. , Karasev V. Yu.
Published: April 2024

A comprehensive decrease in the particle size and a change in the surface morphology, depending on an exposure time in plasma in krypton, have been experimentally established. The results of the size degradation and the surface modification are compared with the results obtained in a lighter inert gas. It is shown that, under similar experimental conditions, the degradation of particles in the heavy gas begins faster.
Direct current generation in Dirac crystal in the field of the wave polarized by Lissajous figure
Authors: Kryuchkov S. V. , Kukhar E. I. , Tarasov V. V.
Published: April 2024

The constant component of the current density aroused in a Dirac crystal due to the alternating electric field of a wave polarized by the Lissajous figure has been calculated within the relaxation time approximation. The amplitude and frequency characteristics of direct current have been analyzed for the different frequency ratios. Some ways of applications of the studied effect have been discussed.
Phased antenna array with digital scheme formation multibeam radiation pattern
Authors: Guoming Lu , Zakharov P. N. , Korolev A. F.
Published: April 2024

A digital synthesis of multibeam radiation pattern is implemented. The parameters and structure of the designed planar antenna array provided isolation between the ports of more than 15 dB. Measurements of the multibeam radiation pattern in the horizontal and vertical radiation planes were carried out.
The local approach to the theory of open optical quantum systems and “violation” of the second law of thermodynamics
Authors: Aleksashin M. K. , Basharov A. M. , Trubilko A. I.
Published: April 2024

Being correctly calculated, energy flows between thermostats into which nonresonantly coupled quantum harmonic oscillators decay, there is no violation of the second law of thermodynamics in using the local approach reported earlier.
Relationship between the spin wave distribution across a ferrite plate thickness and the directions of wave’s group and phase velocities
Authors: Lock E. H. , Gerus S. V.
Published: April 2024

The general nonreciprocal properties of surface and backward spin waves in a tangentially magnetized ferrite plate are investigated. It is established the rule that determines interconnection between the spin wave localization over the ferrite plate thickness and the directions of group and phase velocities of the wave.
Influence of the exchange interaction between the magnetic layers of a THz spin-injection emitter on its operation efficiency
Authors: Chigarev S. G. , Byshevski-Konopko O. A.
Published: April 2024

The effect of a 5 nm thick non-magnetic electrically conductive Mo layer placed between the magnetic layers Fe and Fe3O4 of the “rod–film” type spin emitter structure on the efficiency of its operation was investigated experimentally. The possibility of increasing the radiation power by more than 2 times was established. It is found that the Mo layer also affects the resistance of the structures, increasing it. The influence of the Mo layer on resistance is qualitatively substantiated due to the appearance of a contact potential difference between the layers of the structure different from the contact potential difference between the two metals.
Electromagnetic spectrum of lightning from space high-speed shooting analysis to study Schumann resonance
Authors: Filatov A. L. , Lukanina L. A.
Published: April 2024

The problem of determining the low-frequency electromagnetic radiation spectrum of lightning activity zones based on the analysis of data obtained from a space-based high-speed camera is investigated. A novel method is proposed for obtaining the electromagnetic spectrum of lightning, based on the hypothesis of the correlation of the time dependences of the radiation intensity of the same lightning discharge, measured in the optical and electromagnetic ranges. The necessity of conducting studies of the influence of local lightning on the processes associated with the Schumann resonance is substantiated.
Magnetic and resistive characteristics of the SrMnO3/La0.7Sr0.3MnO3 heterostructure in a wide temperature range
Authors: Sizov V. E. , Shaikhulov T. A.
Published: April 2024

Magnetic and resistive properties of the antiferromagnet–ferromagnet SrMnO3 La0.7Sr0.3MnO3 heterostructure were studied in the temperature range of 50–300 K using magnetotransport measurements. It is established that in the heterostructure, the SrMnO3 layer is in an antiferromagnetic state at room temperature, which is higher than its temperature for a single layer, and the magnetization of the heterostructure exhibits the properties of unidirectional anisotropy. This conclusion is also confirmed by the ferromagnetic resonance spectra
Capillary constant and surface tension of isobutane–hydrogen solution in temperature range of 298–348 K
Authors: Andbaeva V. N. , Khotienkova M. N.
Published: April 2024

We presented the results of measuring of the capillary constant of isobutane–hydrogen solution in the temperature range of 298.15–348.15 K at pressures from the saturation pressure of pure isobutane up to 4 MPa. The surface tension of the solution was determined. The equations approximating the concentration and pressure dependences of the capillary constant and surface tension are constructed.
Investigation of semiconductor materials by the thermo-optical method in a magnetic field
Authors: Kotov A. N. , Starostin A. A. , Shangin V. V. , Bobin S. B. , Lonchakov A. T.
Published: April 2024

The results of studying the effect of temperature and magnetic field on the relaxation of the thermo-optical signal in semiconductor samples with different electronic spectra n-Ge, n-InSb, ZnSe:Ni are presented. The results were obtained using a two-beam fiber-optic “pump–probe” method with a Fabry–Perot interferometer in the temperature range from 4.2 to 300 K with the application of a magnetic field up to 8 T. The significant change of behavior of reflected probing beam with wavelength of 1530 nm was found after the action of a pump pulse for the sample of n-Ge at temperatures below 30 K and a field induction of more than 2 T. This phenomenon is caused by transformation of electronic structure.
Ising nematic in J1–J2 square-lattice Heisenberg model within self-consistent spin-wave theory
Authors: Ignatenko A. N. , Irkhin V. Yu.
Published: April 2024

We study the Ising nematic ordering, the Ising nematic phase transition, and the temperature behavior of the short-range order parameters in spin 1/2 quantum Heisenberg model on two-dimensional square-lattice with exchange parameters of nearest and next-nearest neighbors. Two versions of the self-consistent spin-wave theory with and without auxiliary pseudofermions are considered.
Ab initio calculations of the magnetic anisotropy of Fe/Pt/Fe heterostructures with surface relaxation included
Authors: Makeev M. Y. , Mamonova M. V.
Published: April 2024

A numerical study of the effect of surface relaxation, the equilibrium change in the interplanar distance, on the values of the magnetic and energy characteristics of the Fe/Pt/Fe system was carried out. The contribution of the spin-orbit interaction to the value of the magnetic anisotropy energy is studied as a function of the thickness of the ferromagnetic film.
High hydrostatic pressure and uniaxial compression as factors of overcoming hardseededness in licorice
Authors: Kruglikov N. A. , Belyaev A. Yu. , Minin M. G. , Yakovlev G. A.
Published: April 2024

In laboratory experiments, when assessing the effects of exposure to licorice seeds of high hydrostatic pressure and uniaxial compression of these seeds, the effect of overcoming hardseededness was established, which was confirmed by high values of the proportion of normally germinated seeds from the total number of hard seeds in the sample under study. The strength of the seed coat determines the maximum force before the destruction of the seed under uniaxial compression.