bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study of influence of volumetric radiating overcooling of a melt on the form of front of crystallization by means of numerical modeling processes of heat transfer at growth of sapphire crystals from the melt
Authors: Vasil’ev M G , Bakholdin S I , Krymov V M 
Published: December 2019

Abstract
It is lead numerical modeling of processes of heat exchange at growth of crystals of sapphire from a melt by Stepanov and Czochralski methods. The influences of volumetric radiating overcooling of a melt and of growth speed on the form of front of crystallization and distribution of temperature near to it is studied. It is shown, that the account of absorption of thermal radiation in a melt can lead to formation of volumetric supercooled areas near to crystallization front and to appreciable change of its shape.
The scanning probe microscopy of the structural, elastic and conductive properties of two-component phthalocyanines
Authors: Gushchina E V , Dunaevskiy M S , Lahderanta E 
Published: December 2019

Abstract
Thin films of two-component H2Pc, PdPc, PbPc, CuPc phthalocyanines were studied by scanning probe microscopy methods. Young’s modulus values of the phthalocyanines films were measured, which made it possible to optimize the regimes for studying soft phthalocyanine films and to select suitable probes with proper stiffness and the magnitude of the force acting onto the surface. For all films, the electric field induced reversible local conductivity switching effect was studied. It is shown that under room conditions it is possible to reversibly change the value of the local conductivity of a copper phthalocyanine film approximately by an order of magnitude. When conducting the experiment under vacuum conditions, a significant weakening of this effect occurs. It has been established that for a CuPc film, a pressure of 20 mbar is the lower boundary value for creating regions of increased conductivity. The observed effect is explained by the penetration of OH− ions (from the surface adsorbed water film) into the phthalocyanine film with the subsequent formation of oxygen-containing complexes that increase conductivity.
Monodisperse spherical mesoporous nanocomposite mSiO2/C-dots/Eu3+ particles with broadband luminescence in the visible spectral range
Authors: Eurov D A , Kurdyukov D A , Medvedev A V , Tomkovich M V , Golubev V G 
Published: December 2019

Abstract
A facile template synthesis has been developed to obtain monodisperse spherical mesoporous nanocomposite mSiO2/C-dots/Eu3+ particles of submicron size exhibiting bright broadband luminescence in the visible spectral range. The use of europium ions made it possible to increase the integrated emission intensity of the nanocomposite particles in the reddish-orange region. The particles have a specific surface area of 540 m2/g, pore volume of 0.35 cm3/g, and average pore diameter of 2.7 nm. The obtained particles are promising for application in nanomedicine as nanocontainers simultaneously serving as biomarkers.
Transient carrier transport and rearrangement of space charge layers under the bias applied to ferroelectric M/PZT/M structures
Authors: Delimova L A , Yuferev V S 
Published: December 2019

Abstract
A drift-diffusion model of unsteady carrier transport in M/PZT/M structure is proposed to account for the formation of the current peak in the current –voltage curves, which is not caused by the domain switching and observed only when the bias and polarization directions coincide. In the model, electrons generated by oxygen vacancies are trapped by titanium deep centers at room temperature and can move by hopping between titanium atoms in the electric field. The polarization is constant across the film thickness while it is zero within defective layers near the contacts. It is shown that a pronounced current peak is formed when an accumulated space-charge layer appears near one of the contacts under the action of the polarization and this effect is purely unstationary.
Giant injection magnetoresistance induced by femtosecond laser pulses in semiconductor / granular film heterostructures with cobalt nanoparticles
Authors: Lutsev L V , Shelukhin L A 
Published: December 2019

Abstract
The light-induced giant injection magnetoresistance in SiO2(Co)/GaAs heterostructures, where the SiO2(Co) structure is the granular SiO2 film with Co nanoparticles, has been studied. It is found that the photocurrent are accompanied by relaxation oscillations caused by the Coulomb influence and transitions between the photocurrent and electrons on the highest level in the interface quantum well. The light-induced magnetoresistance reaches its maximum value in the avalanche onset region and has the local minimum at the higher voltage. The local minimum is explained by delocalization of the highest level in the interface quantum well and by decrease of the probability of the backscattering process of injected electrons on deeper levels.
Stress evolution during growth of AlN templates on c-Al2O3 substrates by plasma-assisted molecular beam epitaxy
Authors: Koshelev O A , Nechaev D V , Brunkov P N , Ratnikov V V , Troshkov S I , Ivanov S V , Jmerik V N 
Published: December 2019

Abstract
We describe stress evolution during plasma-assisted molecular beam epitaxy (PAMBE) of AlN nucleation and buffer layers on c-Al2O3 substrates at varying growth temperatures of 780 and 850°C. Moreover, different mechanisms of stress generation in the growing AlN films, related to the processes of grain coalescence and impact of Me-excess during PA MBE by migration enhanced epitaxy and metal-modulated epitaxy, are considered.
Investigation of the emission properties of a silicon blade-type cathode
Authors: Filippov S V , Kolosko A G , Popov E O , Demin G D , Makhiboroda M A , Djuzhev N A , Gryazneva T A , Korotkov S Yu 
Published: December 2019

Abstract
The present paper describes the properties of a silicon blade-type cathode with high technological reproducibility. The emission characteristics were obtained using a modern computerized method for studying field emission cathodes in a non-destructive pulsed mode with a flat anode. The technique includes an assessment of the emission current stability, an estimate of the magnitude of the effective parameters of the cathode (field enhancement and emission area) and the degree of their fluctuations over time. A numerical analysis of the glow patterns of the field emission projector was also performed, representing of the distribution of the current load along the edge of blade-type field emitter.
Tamm plasmon-based cavity with a quasicrystalline type structuration
Authors: Morozov K M , Gubaydullin A R 
Published: December 2019

Abstract
We have theoretically investigated Tamm plasmon structure covered by a quasicrystal symmetry subwavelength grating. We show that such structures can support plenty of high-Q hybrid optical eigenstates. The structure consists of a GaAs/Al0.95Ga0.05As Bragg reflector covered with a subwavelength Fibonacci silver/resist sequence. For the F
5 type coverage, two different operation regimes controlled by filling factor value were shown. We demonstrate the anti-crossing behaviour of these states spectral position. The considered system can be useful to enhance the emission of broadband light-emitting materials such as organic dyes and small molecules.
Structural and morphological characteristics of GaN-based hybrid heterostructures grown on por-Si
Authors: Zolotukhin D , Lenshin A , Goloshchapov D , Mizerov A , Arsentyev I , Leiste H , Seredin P 
Published: December 2019

Abstract
GaN/Si(111) heterostructures were grown by plasma-assisted molecular beam epitaxy on usual Si(111) substrates and compliant por-Si/Si(111) substrates without using AlN buffer layer. The positive influence of the high-temperature nitridation step, as well as the usage of a compliant substrate on crystalline quality, was confirmed. We got a crack-free 850-nm-thick GaN layer at room temperature by using the low-temperature GaN buffer layer with nanocolumnar morphology.
Electronic structure and optical characteristics of the hybrid GaN/por-Si heterostructures
Authors: Zolotukhin D , Lenshin A , Goloshchapov D , Mizerov A , Arsentyev I , Leiste H , Rinke M , Seredin P 
Published: December 2019

Abstract
GaN/Si(111) heterostructures grown by plasma-assisted molecular beam epitaxy on routine Si(111) substrates and compliant por-Si/Si(111) substrates without using AlN buffer layer was studied by using various structural and spectroscopy methods of analysis. XPS study revealed that the layer is grown on the compliant substrate of por-Si being closer to the stoichiometric composition. The shift of the A1(LO) mode in the Raman spectrum confirms the lattice-matched growth type on the compliant substrate in comparison with the routine c-Si substrate. The experimentally determined value of the optical bandgap width for the epitaxial GaN layer grown on por-Si substrate exceeds that of the layer grown on single-crystalline silicon c-Si by 0.1 eV
Determination of the fractal dimension of mesopores in metal-oxide structures obtained via sol-gel synthesis
Authors: Maraeva E V , Permiakov N V , Khalugarova K N , Abrashova E V 
Published: December 2019

Abstract
The work is devoted to the development of a combined method of analyzing the porous structure of metal oxide materials. The method is based on a combination of fractal analysis from data obtained by the sorption method using a thermodynamic approach and fractal analysis of atomic force microscopy images. The objects under research are optically transparent materials of the SiO2 – SnO2 – ZnO system, obtained by the sol-gel technology.
Spinodal decomposition with formation of composition oscillations at low temperature GaInP - GaAs synthesis
Authors: Moskvin P P , Skurativskyi S I , Kuznetsov V V 
Published: December 2019

Abstract
The Cahn-Hillard equation is adapted to consider the spinodal decomposition process of semiconductor solid solutions. The obtained differential equation for the decomposition of a material is used to describe the composition modulation effect observed during the synthesis of GaxIn1-xP-GaAs heterostructures. The numerical simulation of the process of spinodal decomposition of the GaxIn1-xP solid solution is performed. The intervals of the thermodynamic parameters for the technological process of the structures synthesis, in which the composition modulation effect should appear, are found.
Formation of micro-and nanostructures under the influence of femtosecond laser radiation on carbon samples in liquid nitrogen
Authors: Khorkov K S , Kochuev D A , Ilin V A , Chkalov R V , Prokoshev V G 
Published: December 2019

Abstract
The paper presents the results of an experimental study of carbon nanostructures and microcrystals formation under the influence of femtosecond laser radiation in liquid nitrogen. In addition to the formation of carbon nanopeaks on the surface, graphene exfoliation, it is possible to form carbon microcrystals due to the mechanism of the subsurface overheating.
Surface features of the AlN optical coating deposited on the facet of a high-power AlGaAs/GaAs semiconductor laser
Authors: Fomin E , Bondarev A , Slipchenko S , Rudova N , Pikhtin N 
Published: December 2019

Abstract
The facets of high-power AlGaAs/GaAs semiconductor lasers were coated with thin dielectric AlN films using reactive ion-plasma technique. The refractive indices of the films were measured by the ellipsometry. It is shown the technique makes it possible to obtain AlN films with a refractive index close to that of a single-crystal material. The scanning probe microscopy was used to estimate the surface roughness of the films. The comparative results of the aging tests of lasers based on the same laser heterostructure with SiO2 and AlN coatings on their facets are presented.
Changing of mechanical characteristics of Co-based amorphous alloy and Fe-based nano-crystalline alloy in the hydrogenous medium under the influence of impulse electric current
Authors: Pluzhnikova T N , Fedorov V A , Yakovlev A V , Pluzhnikov S N , Fedotov D Y 
Published: December 2019

Abstract
Experimentally established the preliminary influence of hydrogen-containing medium (NACE) in cobalt-based amorphous alloys reduces the temperature of the onset of ductility during annealing. The structure of the surface changes forming in the holding of samples in the NACE medium either separate NaCl crystals or branched crystalline structures on the surface. A layer of oxide appears on the nanocrystalline alloy is preventing in heat exchange between the sample and environment. The passing of the impulse electric current j = 108 – 109 A/m2 results increases mechanical stress releases comparing to non-affected samples by the hydrogen-containing medium because of the temperature increase. The amorphous structure proves to be more resistant under simultaneous influence with the impulse electric current to the effect of the hydrogen medium NACE compare to the nanocrystalline one.
Thin amorphous silicon films crystallization upon flexible substrates
Authors: Serdobintsev A A , Luzanov V A , Kozhevnikov I O , Ryabukho P V , Mitin D M , Bratashov D N , Starodubov A V , Pavlov A M 
Published: December 2019

Abstract
A novel method for thin silicon films crystallization that combines advantages of laser- and metal-induced crystallization technologies is reported. Polycrystalline silicon films were synthesized on flexible polyimide substrates following the proposed approach. Films obtained possess high crystal structure regularity and crystallinity.
Growth and optical properties of GaPN/GaP heterostructure nanowire array
Authors: Koval O Yu , Sapunov G A , Fedorov V V , Mukhin I S 
Published: December 2019

Abstract
The study is devoted to synthesis and investigation of the optical properties of GaPN/GaP nanowire (NW) arrays grown on Si substrate (111) with plasma-assisted molecular beam epitaxy (PA-MBE). First, we demonstrate the growth of axial GaPN/GaP and GaP NW heterostructures. The morphology of GaP and GaPN/GaP NW arrays was investigated with scanning electron microscopy (SEM) to show that at low growth fluxes of activated nitrogen self-catalytic growth regime and nanowires morphology are preserved. Raman spectroscopy was used for investigation of phonon spectra features. Optical properties of the GaPN NW arrays were determined at room temperature with photoluminescence (PL) spectroscopy. Analysis of both Raman spectroscopy and PL results allowed to analyze the GaPN/GaP NWs chemical composition. Dilution of GaP NWs with N allows to significantly increase PL intensity and obtain broad PL signal in the optical spectral region demonstrating the potential of GaPN NWs for future nano-optoelectronics and photonics.
Raman spectroscopy estimation of the carrier concentration and the value of strain in monolayer graphene films grown on 4H-SiC
Authors: Eliseyev I A , Davydov V Yu , Smirnov A N , Nestoklon M O , Dementev P A , Lebedev S P , Lebedev A A , Bokai K A , Usachov D Yu 
Published: December 2019

Abstract
Comprehensive study of high-quality monolayer graphene samples grown by thermal destruction of the Si-face of the 4H-SiC substrate was carried out. Analysis of the data obtained by Raman spectroscopy and angle-resolved photoemission spectroscopy suggest the need to use the Fermi velocity in the graphene layer under study to obtain a correct estimate of the electron concentration and strain values using Raman data. This statement is valid not only for graphene on the SiC substrate, but for graphene on any other substrate as well, since the Fermi velocity in graphene depends on the dielectric constant of the substrate.
Dielectric spectroscopy of thermoplastic polyimide R-SOD in the region of medium and high temperatures
Authors: Dao T H , Nikonorova N A , Castro R A 
Published: December 2019

Abstract
Molecular mobility and charge transport in R-SOD aromatic thermoplastic polyimide were studied by dielectric method. Dielectric spectra of all samples in the examined temperature and frequency range revealed two regions of dipole polarization relaxation. The β- process is determined by local motion of the phenyl rings in the diamine and dianhydride moieties of the macromolecule with the adjacent groups. The α-process can be associated with crossing the glass transition temperature, i.e., with the segmental large-scale mobility of the main chains. The introduction of nano-additives (R-SOD 3%) does not change the relaxation times in the regions of β and α process, but leads to an increase in intensity compared to pure polyimide R-SOD.
Crystal structure transformations during phase transitions in homologues of n-alkanes: C23H48, C24H50, C25H52 as revealed by FT-IR spectroscopy
Authors: Gur’eva S A , Marikhin V A , Myasnikova L P , Volchek B Z , Medvedeva D A 
Published: December 2019

Abstract
The dependence of the IR absorption spectrum on the type of symmetry of crystallographic cells allowed us to investigate the kinetics of phase transitions. It is confirmed that the first order solid-phase transition develops by a heterogeneous mechanism in a narrow temperature range ΔT ⩾ 1 K.
Study of GaAs oxidation in the low-current Townsend discharge
Authors: Lodygin A N , Portsel L M , Snigirev L A , Kirilenko D A , Astrov Yu A 
Published: December 2019

Abstract
An anodic oxidation of GaAs substrates in a non-self-sustained low-current dc Townsend discharge is investigated. The process is carried out at the room temperature in a three-electrode microreactor filled by 98%Ar + 2%O2 gas mixture. Investigation of the oxidation kinetics indicates that the formed oxide is characterized by a high resistivity, ρ ∼ 1011 Ω·cm. It is demonstrated the application of the method for formation of oxide films with dimensions of tens of microns, which thickness is on the nanometer scale. Examination of the “GaAs substrate - oxide layer” interface using the high resolution transmission electron microscopy has revealed that the oxide is characterized by the amorphous structure.
Optical properties of CdTe/ZnTe structures with thin CdTe layers
Authors: Agekyan V , Chukeev M , Filosofov N , Karczewski G , Resnitsky A , Serov A 
Published: December 2019

Abstract
The optical properties of series of CdTe/ZnTe heterostructures with two built-in planar CdTe inclusions of thickness 4.0 and 1.5 monolayers are investigated. The temperature behavior of the exciton luminescence intensity at above-barrier and under-barrier excitation depends on the ZnTe barrier thickness which varies from 15 to 55 monolayers. It occurs that the shape of exciton luminescence bands changes strongly under the increasing optical excitation. The excitation luminescence spectra are studied in the temperature range 5 – 80 K.
Nanoscale films of bismuth and antimony: production technologies and properties
Authors: Makarova E S , Tukmakova A S , Novotelnova A V , Kablukova N S 
Published: December 2019

Abstract
We studied the line of bismuth and antimony thin films obtained by thermal evaporation with or without additional annealing or zone recrystallization under a coating. The dependence of film structure on the production technology and substrate type has been shown. The dependence of galvanomagnetic properties of thin films on the structure has been investigated.
Two-dimensional position-sensitive spectrometer for registration of ionizing radiation
Authors: Bogdanov A A , Eremin I V , Chichagov Yu V , Eremin V K , Tuboltsev Yu V , Verbitskaya E M , Bezbah A A , Fomichev A S , Kiselev O A , Kostyleva D A 
Published: December 2019

Abstract
A new two-coordinate position-sensitive spectrometer for the measurements of spatial and energy distribution of ionizing particles was developed. The sensitive elements of the device are two orthogonal 64 strip semiconductor detectors whose signals are read out by two Application-Specific Integrated Circuits (ASIC) IDE1140 comprising 64 spectrometric channels each. Control, pre-processing data acquisition and transfer to a computer are carried out using FPGA circuit EP3C16Q240. The main spectrometer characteristics obtained in the measurements are: equivalent noise charge of 0.7 fC and integral nonlinearity is below 1% in the range from 5 to 160 fC.
Measurement of short-lived Φ(1020) and K*(892)0 resonances in heavy-ion collisions at NICA energies using the MPD experiment
Authors: Ivanishchev D. , Kotov D. , Malaev M. , Riabov V. , Ryabov Yu. 
Published: December 2019

Abstract
The K*(892)0 and Φ(1020) mesons are copiously produced in hadronic and heavy-ion collisions and carry a wealth of information on different aspects of the interactions, including the properties of the hadronic phase, relative interplay of the radial flow and coalescence at intermediate momentum. For these reasons, measurements of K*(892)0 and Φ(1020) production is an important part of the experimental program of the MPD experiment at NICA. We discuss prospects for K*(892)0 and Φ(1020) measurements in the MPD experimental setup as well as results of the feasibility studies performed using the full-scale Monte Carlo simulations of the detector response.
Studying the mechanisms of the hadron jets production in U+U collisions at

NsN=192

GeV
Authors: Berdnikov A. , Berdnikov Ya. , Kotov D. , Zharko S. , Radzevich P. 
Published: December 2019

Abstract
Studying the properties and evolution of the quark-gluon plasma (QGP) is one of the main directions in modern nuclear physics. The leading direction in the QGP studies is the research of the particle production originating from hard scattering of partons produced in the ultra-relativistic heavy nuclei collision. Light mesons (π0, η and KS
) invariant spectra and nuclear modification factors measurements at high transverse momenta are used for the parton energy loss models free parameters estimate in large systems and to examine various scaling behaviours. Spherically asymmetric uranium nuclei at

N

s

N

=
192

GeV are used to determine the influence of geometrical parameters of the colliding system on the fragmentation of hard partons produced in high energy collision of heavy nuclei. This paper presents differential transverse momentum spectra and nuclear modification factors of KS
mesons in U+U collisions at

N

s

N

=
192

GeV measured in a wide transverse momentum range and different centrality intervals with PHENIX experiment at RHIC.
Jet-Quenching Studies Using Leading Mesons in Cu+Au Collisions at

NsN=200

GeV
Authors: Berdnikov A. , Berdnikov Ya. , Kotov D. , Radzevich P. , Zharko S. 
Published: December 2019

Abstract
Quark-gluon plasma (QGP) is a hot and dense color-charged medium, created in ultra-relativistic heavy nuclei collisions. Jet-quenching is one of the evidence for QGP formation and manifests itself in suppressed hadron production at high transverse momenta when compared to proton-proton collisions. We present results of jet-quenching studies in Cu+Au collisions at

N

s

N

=
200

GeV using production of leading mesons (π
0, η, KS
, ω). Measurements are performed with PHENIX spectrometer at RHIC. Yields of π
0, η, KS
, and ω mesons and reconstructed jets show the same suppression level at high transverse momenta region within uncertainties when compared to p+p results. The suppression level of π
0, η, KS
, and ω mesons in Cu+Au collisions is equal within uncertainties to one measured in Au+Au and Cu+Cu collisions at

N

s

N

=
200

GeV at similar participant nucleon numbers.