bluuebunny/crossref_metadata_2025 huggingface dataset:
О механизме поглощения и восстановления пропускания излучения в канале мелкомасштабной самофокусировки короткого лазерного импульса в неодимовом стекле
Authors: Быковский Н.Е. , Сенатский Ю.В.
Published: October 2019

In the study of small-scale self-focusing (SSF) of a 0.5 ns Nd-laser pulse with 3-5 GW/cm2 intensity in Nd-glass samples, in addition to the characteristic filamentary damage, spectral broadening and laser radiation scattering, a jump in absorption in glasses at the wavelengths 1.06 µm and 0.66 µm was registered also. The coefficient of the induced absorption (IA) in the samples reached 0.15 cm– 1. Restoration of the transmission in the media after the end of the laser pulse had occurred over the time of 15-35ns for phosphate and 5-10 ns for silicate glasses. The physical picture of the IA effect detected as far back as the 1980-s, however, had not been clarified. Current analysis of the experimental data has shown that the absorption jump could be caused by the rapid populating of the 4I11/2 lower laser level of Nd3+ ions in glasses due to the nonlinear processes in the SSF channel: Raman scattering and spectral broadening of the laser radiation. The rates of the 4I11/2 level depopulation and recovery of the transmission were determined by dimensions of the regions with excited Nd3+ ions arising in the glass samples at the interference of laser and scattered radiation as well as by thermal properties of glasses.
Спектральные и структурные характеристики вольфраматов (Lu-=SUB=-1-x-=/SUB=-Eu-=SUB=-x-=/SUB=-)-=SUB=-2-=/SUB=-(WO-=SUB=-4-=/SUB=-)-=SUB=-3-=/SUB=-
Authors: Шмурак С.З. , Кедров В.В. , Киселев А.П. , Фурсова Т.Н. , Зверькова И.И. , Хасанов С.С.
Published: October 2019

Investigated are the structure, luminescence, and IR absorption spectra of
(Lu1−xEux)2(WO4)3 solid solutions in a wide range of Eu concentrations (0 ≤ x ≤ 1). A sequential
replacement of two types of crystalline phases occurs with an increase in Eu concentration. The
orthorhombic phase (Pbcn space group) of tungstate solid solutions is observed at 0 ≤ x < 0.5. A
monoclinic phase (C2/c space group) arises along with the orthorhombic one in the range of 0.5
≤ x ≤ 0.8, while at x > 0.8, the solid solution has a monoclinic structure. The correspondence
between the structure and spectral characteristics of these compounds is established. A change in
the structural state results in a change in luminescence spectra, as well as in the spectra of
luminescence excitation of tungstates. The isotherm of water adsorption by the tungstate samples
and its effect on their spectral and structural characteristics are studied in view of the wetting
ability of (Lu1−xEux)2(WO4)3 solid solutions. It is established that the maximum luminescence
under the resonant excitation of Eu3+ ions is observed in the samples with a monoclinic C2/c
structure at x ~0.9.
Фотоупругие свойства кристаллов сульфата калия
Authors: Стадник В.И. , Матвиив Р.Б. , Щепанский П.А. , Рудиш М.Я. , Когут З.А.
Published: October 2019

The spectral dependences of the absolute piezo-optic coefficients of potassium sulfate crystals are studied and their insignificant dispersion dependence is established. The matrix of elasto-optic coefficients рin of these crystals is filled using the values of elastic stiffness coefficients and absolute piezo-optic coefficients. The coefficient of the acousto-optic efficiency М2 is estimated and it is shown that, considering the highest values, it is more than an order of magnitude higher than that of quartz and strontium borate crystals. Taking into account the short-wavelength boundary of the transparency region of potassium sulfate crystals (~ 170 nm), it is proposed to use them for acousto-optic modulation of ultraviolet radiation.
Долгоживущие центры фотокатализа, создаваемые в ZnO резонансным возбуждением экситона
Authors: Титов В.В. , Лисаченко А.А. , Акопян И.Х. , Лабзовская М.Э. , Новиков Б.В.
Published: October 2019

Along with TiO_2, ZnO is the main photocatalyst for a wide class of redox reactions used to convert light energy into chemical and for environmental cleanup. It has been shown that the creation in ZnO of surface intrinsic defects in ZnO i.e. vacancies in the anionic and cationic sublattices (F-type and V-type centers) - makes it possible to create long-lived (up to 10^3 s) photocatalysis centers and thus fundamentally (tens of times) to increase the quantum yield of reactions. Slow surface states — photocatalysis centers — are created by the diffusion of electrons and holes generated during interband transitions in the volume of the photoactivated sample. However, the transfer efficiency is sharply reduced due to carrier recombination and losses when overcoming the Schottky surface barrier. In this work, In order to reduce these losses during energy transfer to the surface, we used in this work neutral energy carriers — excitons. The high (60 meV) exciton binding energy in ZnO allows it to move at room temperature without decay. The radiation loss of the exciton energy in our experiments is effectively reduced by the formation of a surface 2D structure. The results obtained confirm the high efficiency of the exciton channel for the formation of surface long-lived F and V centers of photocatalysis in the processes of oxygen photoadsorption and photodesorption, imitating the full cycle of the redox photocatalytic reaction.
Динамика трехкомпонентной делокализованной нелинейной колебательной моды в графене
Authors: Щербинин С.А. , Семенова М.Н. , Семенов А.С. , Корзникова Е.А. , Чечин Г.М. , Дмитриев С.В.
Published: October 2019

AbstractThe dynamics of a three-component nonlinear delocalized vibrational mode in graphene is studied with molecular dynamics. This mode, being a superposition of a root and two one-component modes, is an exact and symmetrically determined solution of nonlinear equations of motion of carbon atoms. The dependences of a frequency, energy per atom, and average stresses over a period that appeared in graphene are calculated as a function of amplitude of a root mode. We showed that the vibrations become periodic with certain amplitudes of three component modes, and the vibrations of one-component modes are close to periodic one and have a frequency twice the frequency of a root mode, which is noticeably higher than the upper boundary of a spectrum of low-amplitude vibrations of a graphene lattice. The data obtained expand our understanding of nonlinear vibrations of graphene lattice.
Изменение термодинамических свойств твердого раствора Si-Ge при уменьшении размера нанокристалла
Authors: Магомедов М.Н.
Published: October 2019

In the framework of the “medium atom” model for a binary alloy, the state equation and the thermodynamic properties of the Si0.5-Ge0.5 solid solution are calculated. Using the RP model of the nanocrystal, the changes of both the state equation and thermodynamic properties are calculated during the transition from a macrocrystal to a nanocrystal of 222 atoms with a geometric Gibbs surface. The calculations were carried out along the isotherms T = 100, 300 and 1000 K, in the pressure range: – 1 < P < 7 GPa. The change in the properties of both at the isochoric and at isobaric (P = 0) decrease in the number of atoms in a nanocrystal were studied. It is shown that at an isobaric (P = 0) decrease of size, the specific volume of the Si0.5-Ge0.5 nanocrystal increases the more, the higher the nanocrystal temperature.
This work was supported by the Russian Foundation for Basic Research (project no. 18-29-11013_mk) and the program no. 6 of the Presidium of the Russian Academy of Sciences (grant no. 2-13)
Структура и динамика решетки двухслойных гетероструктур титаната бария-стронция и слоистого титаната висмута разной толщины на подложке окcида магния
Authors: Анохин А.С. , Головко Ю.И. , Мухортов В.М. , Стрюков Д.В.
Published: October 2019

The results of the structure and lattice dynamics study of Bi4Ti3O12 films with a thickness varying from 4 to 430 nm on a (001) MgO substrate with a preliminarily deposited Ba0.4Sr0.6TiO3 (4 nm) sublayer are presented. Two-layer structures were fabricated by high-frequency sputtering of ceramic targets of the appropriate composition. X-ray diffraction studies at room temperature showed that in such heterostructures the c axis of the Bi4Ti3O12 film is perpendicular to the substrate plane, and the [100] axis makes an angle of ± 45◦ with the [100] MgO axis. Up to ≈ 40 nm of Bi4Ti3O12 film thickness, the unit cell have a compression strain in the normal to the substrate plane direction and tensile strain in the interface plane, for large thicknesses the sign of the deformation changes. The frequency shifts of phonon modes in the Bi4Ti3O12 film and the appearance of additional peaks in the Raman spectra were observed. It is indicating on increasement of monoclinic distortion of the films crystal structure compared to the bulk crystal.
Возбуждение волн солитонного типа в кристаллах стехиометрии A-=SUB=-3-=/SUB=-B
Authors: Захаров П.В. , Старостенков М.Д. , Корзникова Е.А. , Ерёмин А.М. , Луценко И.С. , Дмитриев С.В.
Published: October 2019

In the work, using the molecular dynamics method, the crystals of composition А3В are considered, for example Ni3Al and Pt3Al, for the possibility of excitation of soliton-type waves in them. To describe the interatomic interactions, the potentials obtained by the immersed atom method were used. It is shown that under a harmonic external action, excitation of soliton-type waves is possible in a Pt3Al crystal, but not in Ni3Al. The occurrence of such compression-extension waves is due to the excitation near the zone of action of discrete breathers with a soft type of nonlinearity, the existence of which is impossible in a Ni3Al crystal. The detected waves can propagate thousands of nanometers along a Pt3Al crystal without any loss of shape or speed. The shape of the received wave corresponds to the kink solution of the sin-Gordon equation. The total amount of energy carried by the wave is determined by the number of rows of atoms involved in the oscillations, we can talk about tens and hundreds of electron volts
Пьезоэлектрические свойства 2D наноаллотропов нитрида бора
Authors: Браже Р.А. , Долгов Д.А.
Published: October 2019

Independent components of the piezomoduli tensor for various boron nitride 2D nanoallotropes are calculated. The essence of the offered approximate method of calculation consisted that the effective dipolar moment of an elementary cell of 2D structure brought to unit of area was expressed through a tensor of elastic rigitities and relative deformations of a cell. It is shown that, besides well-known graphene-like boron nitride h-BN, both the other its hexagonal and tetragonal nanoallotropes possessing higher, in comparison with h-BN, piezoelectric properties can be of practical interest.
Фазовые переходы и термодинамические свойства модели Поттса с числом состояний спина q=4 на треугольной решетке
Authors: Муртазаев А.К. , Курбанова Д.Р. , Рамазанов М.К.
Published: October 2019

The Wang-Landau Monte Carlo algorithm has been used to study the phase transitions and thermodynamic properties of the two-dimensional ferromagnetic q = 4 Potts model on a triangular lattice. A nature of phase transition has estimated using the methods of the fourth order Binder cumulants and the histogram analysis. It has been established that a first-order phase transition is observed in the model under study.
Упругие свойства монокристаллов La-=SUB=-0.7-y-=/SUB=-Pr-=SUB=-y-=/SUB=-Ca-=SUB=-0.3-=/SUB=-MnO-=SUB=-3-=/SUB=- (0≤ y≤0.3)
Authors: Зайнуллина Р.И.
Published: October 2019

Results of the investigation of the temperature dependences of the velocity of longitudinal sound and internal friction in the ferromagnetic La 0.7-y Pr y Ca 0.3 MnO3 single crystals (0≤ y≤0.3) with first-order magnetic phase transition are presented. In the paramagnetic state, the temperature dependences of the velocity of sound and the internal friction demonstrate extended temperature hysteresis, which indicates the ingomogeneity of the paramagnetic state. It seems likely that the main reason of this ingomogeneity is structural phase separation.
Эволюция структуры и свойств сплава Ni-=SUB=-47-=/SUB=-Mn-=SUB=-42-=/SUB=-In-=SUB=-11-=/SUB=- после пластической деформации
Authors: Калетина Ю.В. , Грешнова Е.Д. , Калетин А.Ю.
Published: October 2019

AbstractResults of the study of the effect of various types of plastic deformation on microstructural features and change in physical and mechanical properties of the nonstoichiometric Heusler alloy Ni_47Mn_42In_11 are shown. It was demonstrated that the deformation by rolling and upsetting leads to an increase in the microhardness and to an embrittlement of the investigated alloy. Severe plastic deformation by torsion under high pressure of 8 GPa at room temperature was found to strongly refine initially coarse grain and to contribute to the formation of a nanocrystalline structure with grain fragments up to 10 nm. In this case, the fraction of viscous constituent on the fracture and the microhardness increased, while the magnetic susceptibility decreased.
Полиморфизм ScBO-=SUB=-3-=/SUB=- при твердофазном синтезе из аморфных прекурсоров
Authors: Шмытько И.М.
Published: October 2019

Detailed X-ray studies of changes in the structure of ScBO3 in the process of successive isothermal annealing of the initial amorphous precursor were carried out. It was shown that, during successive annealing of an amorphous precursor, the crystalline phase is first formed at an annealing temperature of 710 ° C, the positions of the reflections of which do not coincide with the position of the reflections of the known calcite structure. This phase exists in a very narrow temperature range (~ 30 ° C) and with an increase in the annealing temperature to 750 ° C, it completely transforms into the known rhombohedral phase of calcite. Using the ENDEAVOUR software complex, the cell parameters, the positions of the atoms in the cell, and the space group of the symmetry of the new phase were determined. It turned out that the new phase corresponds to the hexagonal structure of vaterite (S.G. P63 / mmc), known for other rare-earth orthoborates (REM).
Влияние отжига на структурные, текстурные, термические, магнитные и люминесцентные свойства наночастиц фторида кальция
Authors: Ильвес В.Г. , Соковнин С.Ю. , Зуев М.Г. , Уймин М.А. , Rahn M. , Kozlova J. , Sammelselg V.
Published: October 2019

Mesoporous nanocrystalline CaF2 powder was obtained by pulsed electron beam evaporation (PEBE) in vacuum. The specific surface area (SSA) of the nanopowder (NP) of CaF2 reached 88.7 m2g. The effect of thermal annealing in air in the temperature range 200–900 oC on particle size, morphology, textural, thermal, magnetic, and luminescent properties of NP was studied. A strong deviation of the obtained nanoparticles from stoichiometry and a significant increase in SSA after annealing at 200 ° C was observed. The obtained CaF2 NP showed ferromagnetic (FM) behavior. The appearance of the FM response can be explained by the formation of structures and radiation defects. An analysis of the pulsed cathodoluminescence (PCL) curves and the magnetization of NP CaF2 allows us to draw conclusions about their relationship.
Влияние энергии ионной стимуляции на удельное электросопротивление углеродных пленок, полученных методом импульсно-плазменного осаждения в атмосфере азота
Authors: Завидовский И.А. , Стрелецкий O.A. , Нищак О.Ю. , Хайдаров A.A.
Published: October 2019

In the paper, thin carbon films deposited by pulse-plasma ion-assisted sputtering of graphite in argon-nitrogen gas mixture are discussed. The EELS and electron diffraction showed the graphite phase enlargement with the ion assistance energy increase. Application of ion assistance during the deposition process made it possible to control the films specific resistivity, altering it from 10^5 to 10^2 Ohm⋅cm.
Бистабильность многостенных углеродных нанострубок, расположенных на плоских подложках
Authors: Савин А.В. , Савина О.И.
Published: October 2019

The stationary states of multi-walled carbon nanotubes are investigated. Numerical simulation has shown that for sufficiently large diameters, nanotubes become bistable systems. Regardless of the interaction with the substrates, they can be in two stable states: in an open, having an internal cavity, and in a collapsed state. The interaction with the flat substrate leads to the flattening of the nanotube, which makes its transition to the collapsed state energetically more favorable (the stronger the interaction, the more advantageous is the transition). It is shown that the change of the shape of a multilayer nanotube due to its interaction with the substrate or due to its collapse leads to a sharp increase in the number of its collective eigenmodes, in which all its layers already take part. The energy profile of the transition between the stationary states of the nanotube is obtained. This profile is a highly asymmetric double-well potential, with the first narrow minimum corresponding to the collapsed state, and with the second wide minimum corresponding to the open state of the nanotube.
Эмиссионные свойства лазерной плазмы при ее возбуждении на молекулярно-кластерных струях углекислоты
Authors: Нечай А.Н. , Перекалов А.А. , Чхало Н.И. , Салащенко Н.Н.
Published: October 2019

The paper presents the results of studies of a gas-jet laser-plasma source of extreme ultraviolet radiation (EUV) based on a conical supersonic nozzle. Molecular cluster CO2 jets were used as targets. By changing the parameters of the gas at the nozzle entrance, various modes of gas outflow were obtained, the influence of these modes on the emission and technical characteristics of the radiation source was studied. An experimentally shown is an increase in EUV emission with an increase in the amount of clustered matter in the jet. A possible relationship was observed between the increase in the intensity of EUV radiation with an increase in the number of clustered matter in the jet.
Использование планарных пермаллоевых микрочастиц для детектирования механических напряжений
Authors: Нургазизов Н.И. , Бизяев Д.А. , Бухараев А.А. , Русских И.В. , Садчиков Ю.В.
Published: October 2019

The results of the study of changes in the magnetic structure of planar permalloy microparticles under a mechanical stress are presented. The particles were formed on glass substrates and had the square shape in the sample plane. It was shown that uniaxial mechanical stresses can be detected from the images of such particles obtained by magnetic force microscope. The ranges of effectively using of the particles for a detection of the stresses were determined depending on the geometrical sizes of the particle.
Исследование оптических, механических и термических свойств свободновисящих пленок на основе нанокомпозитных материалов MoSi-=SUB=-2-=/SUB=-N-=SUB=-x-=/SUB=- и ZrSi-=SUB=-2-=/SUB=-N-=SUB=-y-=/SUB=-
Authors: Зуев С.Ю. , Лопатин А.Я. , Лучин В.И. , Салащенко Н.Н. , Татарский Д.А. , Цыбин Н.Н. , Чхало Н.И.
Published: October 2019

The optical, mechanical, and thermal properties of freestanding films based on nitrided molybdenum and zirconium disilicides were investigated. It has been shown that nitriding of silicides leads to a significant increase in the thermal stability of the films. So, if crystallization of initially amorphous freestanding MoSi2 or ZrSi2 films is observed at temperatures of 330-370°C, the introduction of nitrogen into the film makes it possible to increase the temperature up to 600-700°С at which MoSi2Nx and ZrSi2Ny (at least for x ≥ 0.25, y ≥ 1.3) films can be used for many hours when heated under vacuum. The study of mechanical tensile strength showed that the ultimate strength is weakly dependent on the nitrogen content in MoSi2Nx films (0 ≤ x ≤ 0.55). Comparison of the properties of MoSi2Nx and ZrSi2Ny films obtained by the magnetron method at the same nitrogen partial pressure demonstrated that at similar values of the transmittance at 13.5 nm, nitrated ZrSi2 films are more effective as protective coatings (less susceptible to oxidation and more resistant to degradation at high temperatures).
Применение сканирующей емкостной силовой микроскопии для выявления примесных фаз в сегнетоэлектрике триглицинсульфат
Authors: Гайнутдинов Р.В. , Толстихина А.Л. , Лашкова А.К. , Белугина Н.В. , Шут В.Н. , Мозжаров С.Е. , Кашевич И.Ф.
Published: October 2019

The results of the study of inhomogeneous ferroelectric triglycine sulfate single crystal with a growth periodic impurity structure TGS - TGS + Cr are presented. The impurity distribution was investigated with scanning capacitance force microscopy (SCFM). The peculiarities of the capacitance variations imaging on a doubled and tripled resonant frequency of electrostatic force are considered. The piezoelectric response, surface potential and surface topography were studied. It is shown that capacitive contrast is formed both at the domain boundaries and in the TGS and TGS + Cr bands. It was shown that SCFM allowed one to observe the impurity spatial distribution in the ferroelectric structure at the difference in the chromium concentration about 0.02-0.08 wt%.
Исследование трещиностойкости покрытий микродугового оксидирования после лазерного легирования оксидом циркония
Authors: Лапицкая В.А. , Кузнецова Т.А. , Чижик С.А. , Комаров А.И. , Фролов Ю.И. , Романюк А.С.
Published: October 2019

The results of the study of the crack resistance of the microarc oxidation coating (MAO) after laser doping with zirconium oxide are presented. The crack resistance was determined by an indentation method with microhardness prints visualization by atomic force microscopy. It was established that laser doping with zirconium oxide leads to a significant hardening of the MAO coating. The stress intensity factor increases by a factor of 2.7 and the damage to the surface decreases by a factor of 2 compared with the initial MAO coating.
Влияние эффектов самовоздействия на распространение импульсов поверхностных магнитостатических волн в структуре магнонный кристалл--диэлектрик--металл
Authors: Высоцкий С.Л. , Павлов Е.С. , Кожевников А.В. , Дудко Г.М. , Филимонов Ю.А. , Стогний А.И. , Marcelli R. , Никитов C.А.
Published: October 2019

The influence of self-action effects on the magnetostatic surface waves (MSSW) pulses propagating in the structure of a one-dimensional magnonic crystal - dielectric - metal, where the choice of dielectric thickness forms an anomalous dispersion region that provides the fulfillment of Lighthill criterion on MSSW solitons formation, is studied. It is shown that in those cases when the portion of anomalous dispersion caused by metallization coincides with the frequency range of Bragg resonance, MSSW solitons are not formed.
Столбиковые ниобиевые оксидные наноструктуры: механизм образования, микроструктура и электрофизические свойства
Authors: Горох Г.Г. , Плиговка А.Н. , Лозовенко А.А.
Published: October 2019

The morphology and microstructure of the columnar niobium oxide nanostructures were investigated. The dependences of their morphological sizes on the anodization voltages (100–450 V) and anodic alumina pore diameters (40–150 nm) were established. The features of ion transfer in the process of niobium local anodizing were investigated and the transport numbers of electrolyte anions and niobium cations were calculated. The formation and growth mechanism was proposed and discussed. The phase composition and electrophysical properties of the column nanostructures were investigated.
Формирование графена на поликристаллическом никеле
Authors: Логинов А.Б. , Божьев И.В. , Бокова-Сирош С.Н. , Образцова Е.Д. , Исмагилов Р.Р. , Логинов Б.А. , Образцов А.Н.
Published: October 2019

The results of graphene layers formation on Ni surface due to methane pyrolysis are presented in this work. The investigation was carried out using technique that allows controlling morphology of the sample surface with high spatial resolution. This technique includes the use of scanning tunnel microscope (STM) introduced inside the reaction chamber which allows to get rid of atmosphere gases impact. Bubble structure of obtained few-layer graphene film with typical diameter about 100 nm was observed. It was found that local morphology of these bubbles can be easily changed by increasing tunnel voltage applied to the STM tip.
Влияние барьерных слоев бериллия на свойства многослойных зеркал Mo/Si
Authors: Зуев С.Ю. , Плешков Р.С. , Полковников В.Н. , Салащенко Н.Н. , Свечников М.В. , Чхало Н.И. , Schafers F. , Sertsu M.G. , Sokolov A.
Published: October 2019

The results of studies of multilayer Mo/Si mirrors with interlayer layers of B4C and Be in the vicinity of a wavelength of 13.5 nm are presented. It is shown that a four-component multilayer mirror of the Mo/Be/Si/B4C type exceeds the Mo/Si mirror by 2% and the Mo/Si/B4C mirror by 1.3%. This mirror also provides the highest spectral bandwidth at half-height (Δλ1/2 = 0.535 nm). An explanation of these effects is given.
Влияние термического отжига на свойства многослойных зеркал Mo/Be
Authors: Смертин Р.М. , Гарахин С.А. , Зуев C.Ю. , Нечай А.Н. , Полковников Н.В. , Салащенко Н.Н. , Свечников М.В. , Sertsu M.G. , Sokolov A. , Чхало Н.И. , Schafers F. , Юнин П.А.
Published: October 2019

AbstractThe influence of thermal action on X-ray optics performance and structure of films and transition regions in multilayer Mo/Be mirrors optimized for a reflection maximum in the interval 11.2–11.4 nm at normal incidence has been considered. The annealing temperature reached 300°C and the annealing time was 1 and 4 h. It has been shown that after thermal annealing in vacuum for 1 h at 300°C, the reflection coefficient rises; however, when the annealing time grows to 4 h, it drops. Grains in molybdenum films become finer, and the profiles of transition regions change from exponential to linear. The period of multilayer mirrors has remained the same under all annealing conditions.
Пленки Bi-замещенных ферритов-гранатов для термомагнитной записи, фотоники и плазмоники: оптимизация условий синтеза с использованием сканирующей зондовой микроскопии
Authors: Прокопов А.Р. , Михайлова Т.В. , Данишевская Е.В. , Шапошников А.Н. , Бержанский В.Н. , Каравайников А.В. , Недвига А.С. , Наухацкий И.А. , Милюкова Е.Т.
Published: October 2019

AbstractWe present the results of studies on the optimization of the synthesis of Bi-substituted iron garnet (Bi : IG) films by liquid-phase epitaxy and vacuum deposition followed by crystallization. The effect of the parameter of mismatch between the crystal lattices of the film and the substrate on the functional properties of thin single-crystal high-coercive Bi : IG films is demonstrated. The regime of high-temperature annealing of deposited films was optimized in order to form layers with a high bismuth concentration for magnetophotonic and magnetoplasmonic structures. It was established that annealing of the Bi : IG layer under a SiO_2 layer deposited on top will reduce the roughness of interfaces in multilayer structures.
Определение электрофизических параметров полупроводника по измерениям микроволнового спектра импеданса коаксиального зонда
Authors: Резник А.Н. , Вдовичева Н.К.
Published: October 2019

We propose a method for determining semiconductors electrophysical characteristics (concentration and mobility of free charge carriers, conductivity) using measurements of the microwave impedance spectrum of a coaxial probe as a function of the applied constant voltage U. The parameters under study are found by solving the corresponding inverse problem using the developed theory of the near-field antenna. A computer program was created that searches for a solution by minimizing the multiparameter discrepancy function using the Nelder–Mead algorithm. The accuracy of the method is analyzed from simulation results in which the impedance is calculated via the obtained charge concentration profile n(x, U) of the depleted layer in the vicinity of the metal-semiconductor contact. The possibility of diagnostics with micron lateral resolution is demonstrated.
Cужение линии поглощения легких атомов щелочных металлов в атмосфере тяжелых инертных газов при росте интенсивности излучения
Authors: Пархоменко А.И. , Шалагин А.М.
Published: October 2019

Abstract The effect of narrowing of the absorption line of light alkali metal ^7Li and ^23Na atoms present in an atmosphere of heavy inert gas (xenon) with an increase in the external radiation intensity has been investigated. For ^7Li atoms at temperature T = 300 K and buffer gas (Xe) pressure $${{p}_{{{\text{Xe}}}}} = 0.002$$ Torr, the linewidth at half maximum decreases by a factor of 1.20 with an increase in the radiation intensity from 1 µW/cm^2 to 2.5 mW/cm^2. For ^23Na atoms at T = 600 K and $${{p}_{{{\text{Xe}}}}} = 0.01$$ Torr, the linewidth at half maximum decreases by a factor of 1.29 with an increase in the radiation intensity from 1 µW/cm^2 to 6 mW/cm^2. The effect of field narrowing of the absorption line is due to the following factors. First, the collisional relaxation of the velocities of light resonance particles in an atmosphere of heavy buffer particles is divided into two stages with significantly different durations: relaxation in the velocity direction (fast stage) and relaxation in the velocity magnitude (slow stage). Second, there are no collisional transitions between hyperfine components of the ground state.
Физически корректные конфигурационные пространства в описании внутренней динамики жесткой молекулы
Authors: Буренин А.В.
Published: October 2019

Abstract A family of configuration spaces in the description of the internal dynamics of a rigid molecule has been considered. It has been shown that the requirement of the physical correctness of the description leads to serious restrictions for such spaces. In particular, only spaces satisfying the Eckart condition are allowed for a nonlinear rigid molecule.
Фононный спектр La-=SUB=-2-=/SUB=-Zr-=SUB=-2-=/SUB=-O-=SUB=-7-=/SUB=-: ab initio расчет
Authors: Чернышев В.А.
Published: October 2019

Crystal structure and phonon spectrum of La2Zr2O7 were studied within the framework of density functional theory and MO LKAO approach. The calculations were performed by using hybrid functionals that takes into account both local and nonlocal (in the Hartree–Fock formalism) exchange. The frequencies, types, and intensities of Raman and IR modes are determined. The elastic constants have been calculated too.
The calculations were performed in the CRYSTAL17 program intended for simulating periodic structures in the MO LCAO approximation.
Влияние свойств водной среды на агрегацию димегина
Authors: Багров И.В. , Дадеко А.В. , Киселев В.М. , Муравьева Т.Д. , Стародубцев А.М. , Гренишин А.С.
Published: October 2019

A comparative study of the influence of an aqueous medium properties on the aggregation of dimegine, photoditazine and radachlorin was carried out. A nonlinear dependence of the molar extinction on the concentration of the photosensitizer in solution was noted, moreover to varying degrees for the dosage form of the solution and solutions prepared using lyophilized photosensitizer powders. It has been shown that the use of surfactants (Pluronic F-127 and polyvinylpyrrolidone) within certain limits reduces the problems associated with the aggregation of the studied photosensitizers.
Генерация капельных квазибесселевых пучков при помощи полупроводникового лазера
Authors: Чистяков Д.В. , Лосев С.Н. , Абдулразак С.Х. , Мыльников В.Ю. , Когновицкая Е.А. , Задиранов Ю.М. , Дерягин Н.Г. , Дюделев В.В. , Кучинский В.И. , Соколовский Г.С.
Published: October 2019

Abstract A method for generation of droplet quasi-Bessel beams using a conical lens with a rounded tip is demonstrated. The study of the longitudinal distribution of the intensity of the obtained quasi-Bessel beam showed that, due to the interference of two wavefronts that occurred as the generating beam passed through the rounded axicon, periodical intensity pulsations that looked like “drops” of light occurred in the resulting beam. These light beams can be used for micromanipulation of biological objects and in super-resolution microscopy. The application of an axicon with a rounded tip for generation of a droplet beam allows considerable simplification and miniaturization of the experimental setup, which paves the way for multiple practical applications.
Геометрическая оптика твист-ориентированного нематического жидкого кристалла с анизотропным поглощением
Authors: Овакимян А.О. , Айвазян А.Э. , Асланян Л.С.
Published: October 2019

The spatial dynamics of polarized light in a smoothly inhomogeneous anisotropic medium mixed with an anisotropic absorbing dye is analyzed. As such a medium, a twist-oriented nematic liquid crystal with a pleochroic dye was considered. In the geometrical-optical approximation, a system of coupled shortened equations for the Cartesian components of the electric component of the light wave is obtained. A system of coupled complex equations was analytically solved and the behavior of a linearly polarized wave in such a medium was analyzed in the case of both absorption and amplification. An asymmetric effect of these two processes on the spatial dynamics of light propagation in the medium is found.
Запись поляризационных голограмм в полимерных пленках с азокрасителями и азополимерами
Authors: Давиденко Н.А. , Давиденко И.И. , Кравченко В.В. , Мокринская Е.В. , Павлов В.А. , Савченко И.А. , Тарасенко В.В. , Чуприна Н.Г.
Published: October 2019

Abstract Based on polymers with the addition of azo dyes as chromophores and azopolymers with the same covalently linked chromophores, recording media for polarization holography are created and their properties are studied when recording holograms of a plane wave front with parallel and perpendicular polarization of recording rays. It is found that the diffraction efficiency and the storage time of holograms are much longer in recording media with films of azo polymers in comparison with polymeric solid solutions of azo dyes. In the latter case, the energy of light is spent only for the trans – cis isomerization of azo dye molecules during exposure of holograms and the polymer chains do not undergo deformation with the formation of a surface relief in the polymer film. Therefore, it is preferable to use recording media based on solid solutions of azo dyes in dynamic polarization holography.
Модифицированная модель Друде-Лоренца, позволяющая учесть топологические характеристики среды
Authors: Маймистов А.И. , Ляшко Е.И.
Published: October 2019

The Drude-Lorentz model, which allows to describe nonlinear response of dielectric or conduc-tor, could be used for describing nonlinear non resonant responses of some exotic media, such as the topological insulators, the Weyl semimetals and the Dirac metals. Generalized Drude-Lorentz model and its simplified version, where the topological effects are taken into account in the minimal order, are presented in paper. A nonlinear conductance of the second order corre-sponding to second harmonic generation and optical rectification effect is obtained in paper as an example of use of the simplified model. It is shown that the ratio of the topological conductance to the ordinary linear conductance contains the constant value that is proportional to the fine structure constant and axion field gradient.
Application of Fe-graphene oxide nanocomposite to improve SERS intensity of polyaromatic hydrocarbons-=SUP=-*-=/SUP=-
Authors: Kahkhaie V. Rezaie , Yousefi M.H. , Darbani M. , Mobashery A.
Published: October 2019

Abstract Raman spectroscopy is used to provide a structural finger-print by which molecules can be identified. SERS technique offers many orders of magnitude enhancement in initial weak Raman signal of some molecules. To detect Raman signal of pyrene, magnetic properties of iron nanoparticles (Fe NPs) was employed along with graphene oxide (GO). Significant differences were discovered in performance of five different SERS substrates which were prepared using magnetized and non-magnetized Fe NPs-GO nanocomposites (FNRC) and Ag nanoparticles. UV-Vis, Raman and FE-SEM analysis presented complete formation of Ag-NPs, GO and FNRCs. The quantity of enhancement measured showed different enhancements from 1.09 up to 3.54 times for pyrene solution on magnetized Fe NP-GO nanocomposite. SERS enhancement showed a reverse relation with GO/Fe precursor rate. Raman shift suggested formation of new bonds. 2.017 RSD factor presented very fast performance only 10 seconds after irradiation of magnetized FNRCs.
Оптические свойства нанокомпозитов на основе сульфидов цинка и олова в нанопористом силикатном стекле
Authors: Сидоров А.И. , Тунг Нго Дуи , Ву Нго Ван , Антропова Т.В. , Нащекин А.В.
Published: October 2019

Spectra of optical density, luminescence, and Raman scattering of micro- and nanodendrites of crystal zinc and tin sulfides in silica nanoporous glass (NPG) with average pore size 25 nm are presented. Sulfide nanodendrites were synthesized by sulfurizing of zinc and tin nanodendrites, which were grown in NPG pores by electrolysis. It is shown that the luminescence of sulfide nanodendrites is caused by the defects of crystal lattice. The main bands of Raman spectrum of nanodendrites are caused by transverse and longitude vibration modes of hexagonal ZnS (wurtzite) and stretching modes of 2H polytype of SnS2 with hexagonal cell. The obtained results can be used for creating of chemical and biosensors, and also in photovoltaics and photocatalyze.
Кинетика затухания теплового излучения поверхностных слоев углеродных материалов при импульсном лазерном возбуждении
Authors: Зеленский С.Е. , Аоки Т.
Published: October 2019

For surface layers of carbon materials, under excitation by a Q-switched neodymium laser, the decay of laser-induced thermal emission is investigated both experimentally and theoretically. It is revealed that the decay curves can be fit with satisfactory accuracy by a sum of two exponential components with the decay times of the order of 10 and 100 ns. Under irradiation by a sequence of laser pulses, the observed transformations of the emission decay curves can be presented as redistribution of intensity of the above-mentioned two components. As a result of computer simulations, it is concluded that the emission decay time is determined by the ratio of the penetration depth of laser radiation and the thermal diffusion length. This fact opens a possibility for estimation of thermal diffusivity of an investigated material in a thin surface layer at high temperatures (thousands of Kelvins).
Плазмон-стимулированное фотолегирование в тонкослойной структуре As-=SUB=-2-=/SUB=-S-=SUB=-3-=/SUB=---Ag
Authors: Индутный И.З. , Минько В.И. , Сопинский Н.В. , Литвин П.М.
Published: October 2019

Abstract The effect of the excitation of surface plasmon polaritons at the silver – chalcogenide glass interface on photostimulated diffusion of silver into the chalcogenide was studied for the first time. To excite plasmons, a high-frequency aluminum diffraction grating with a period of 248.5 nm was used, onto which a two-layer Ag–As2S3 structure was deposited. It was found that the process of photostimulated diffusion of silver into the chalcogenide layer is accelerated (that is, the photosensitivity of such a structure increases) when the surface plasmon polariton is excited at the Ag – As2S3 interface during the exposure. The dynamics of photostimulated changes in the optical characteristics of the structure, including the initial stage of the photodiffusion process, was registered by recording the changes in the plasmon excitation characteristics with the exposure time.
Влияние угла наклона канала на конвективное смешение, вызванное неустойчивостью механического равновесия тройной газовой смеси при изотермической диффузии
Authors: Асембаева М.К. , Косов В.Н. , Красиков С.А. , Федоренко О.В.
Published: October 2019

The features of the convective regime that arose due to the instability of mechanical equilibrium of the ternary helium – argon – nitrogen gas mixture during isothermal diffusion were experimentally studied. The influence of the slope angle of the diffusion channel on the intensity of convective flows is considered. The intensity of partial transfer of components in the inclined channel at elevated pressures was measured. A nonlinear dependence of the mixing rate of the components on the angle of inclination was found. It has been established that the observed transfer of components, which is atypical for diffusion, is possible with a certain composition of the gas mixture.
Эпитаксиальный рост cульфида цинка методом молекулярного наслаивания на гибридных подложках SiC/Si
Authors: Антипов В.В. , Кукушкин С.А. , Осипов А.В.
Published: October 2019

In this work, we obtained epitaxial films of zinc sulfide on silicon by the ALD method. To avoid the interaction between silicon and zinc sulphide on the silicon surface, a high-quality buffer layer of silicon carbide ~ 100 nm thick was preliminarily synthesized by chemical substitution of atoms. The diffraction of high energy electrons showed that the ZnS layers are epitaxial. Using ellipsometric methods, it has been proved that the grown ZnS layers are transparent in the photon energy region up to 3 eV, which is of crucial importance for applications in optoelectronics.
Оптически индуцированные эффекты в облученных ультрадисперсных керамиках Al-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=--BeO
Authors: Никифоров С.В. , Борболин А.Д. , Марфин А.Ю. , Никифоров А.Ф.
Published: October 2019

Optically induced effects in ultrafine Al2O3-BeO ceramics irradiated with high doses of a pulsed electron beam (130 keV) were investigated. It is found that optical (470 nm) excitation of ceramics results in optically stimulated luminescence due to the emptying of traps associated with thermoluminescence peaks at 380 and 530 K. It is found that these traps are characterized by a complex energy spectrum with a non-uniformly distributed photoionization cross section. The prospect of using optically stimulated luminescence of Al2O3-BeO ceramics in high-dose dosimetry (3-30 kGy) is proved.
Экспериментальное исследование пассивного способа ослабления трансзвукового баффета
Authors: Брутян М.А. , Волков А.В. , Потапчик А.В.
Published: October 2019

Experimental studies of buffeting onset phenomenon physical picture on a model of a supercritical airfoil at transonic speeds are presented. Passive control method of this phenomenon based on application of the special jet vortex generators is given. It is shown that application of this method leads to delaying of the onset and decreasing of buffeting phenomenon, and at the result – to improve aerodynamic characteristics of airfoil.
Анализ структуры наночастиц, формируемых методом лазерной абляции пористого кремния и микрочастиц кремния в воде
Authors: Заботнов С.В. , Колчин А.В. , Кашаев Ф.В. , Скобёлкина А.В. , Нестеров В.Ю. , Преснов Д.Е. , Головань Л.А. , Кашкаров П.К.
Published: October 2019

Silicon nanoparticles with the size from 50 nm to 300 nm depending on used targets were formed by the picosecond laser ablation technique of porous silicon and silicon microparticles in water. Raman spectra analysis of the produced nanoparticles revealed a slight presence of the amorphous phase (10 – 12%) in them for the case of ablation of micro- and mesoporous silicon layers and almost complete crystallinity as a result of laser fragmentation of the silicon micropowders in water. The results can be helpful for further use of the considered nanoparticles in applications of photonics and biomedicine.
InAlAs/InGaAs/InP HEMTs с композитным каналом и улучшенными пробивными характеристиками
Authors: Малеев Н.А , Васильев А.П. , Кузьменков А.Г. , Бобров М.А. , Кулагина М.М. , Трошков С.И. , Малеев С.Н. , Беляков В.А. , Петрякова Е.В. , Кудряшова Ю.П. , Фефелова Е.Л. , Макарцев И.В. , Блохин С.А. , Ахмедов Ф.А. , Егоров А.В. , Фефелов А.Г. , Устинов В.М.
Published: October 2019

High-electron mobility transistor (HEMT) with improved breakdown characteristics has been developed. Composite InGaAs channel structure was used in combination with fully selective double recess device fabrication process. HEMTs with T-gate length of 120 nm and width 4x30 m demonstrate maximum extrinsic transconductance of 810 mS/mm, maximum drain current density of 460 mA/mm and gate-drain reverse breakdown voltages as high as 8–10 V. Devices cut-off frequency exceed 115 GHz. Because of increased breakdown voltage and fully selective double recess fabrication process designed HEMTs are promising for medium power mm-wave MMIC amplifiers.
Исследование спектров фотолюминесценции нанокристаллов AgInS-=SUB=-2-=/SUB=-/ZnS при воздействии γ-излучения
Authors: Мазинг Д.С. , Романов Н.М. , Мошников В.А. , Александрова О.А. , Корепанов О.А.
Published: October 2019

The effect of different doses of γ-radiation from a 137Cs source on photoluminescence of Ag-In-S nanocrystals covered with a shell of wider bandgap ZnS was investigated. The dynamics of changes in the nanocrystals photoluminescence depending on the dose of γ-radiation was shown. It was established that the AgInS2 / ZnS nanoparticles retain their photoluminescent properties and colloidal stability upon reaching the absorbed dose of 6 • 10^3 Gy (to water). Residual photoluminescence persisted when the absorbed dose reached 10^6 Gy. It was shown that AgInS2 / ZnS nanocrystals can be used in medical and biological studies in which increased resistance to gamma radiation is needed.
Аномалии в фотовольтаических характеристиках многопереходных солнечных элементов при сверхвысоких концентрациях солнечного излучения
Authors: Минтаиров М.А. , Евстропов В.В. , Минтаиров С.А. , Шварц М.З. , Калюжный Н.А.
Published: October 2019

An anomaly arising in photovoltaic characteristics at ultra-high concentrations (more than 2000 suns) in triple-junction GaInP/GaAs/Ge and in the double-junction GaInP/GaAs solar cells has been studied. The light IV-curves at different sun concentrations and dependence of open circuit voltage on photogenerated current have been analyzed. It is shown that the anomaly is caused by the photovoltaic effect source, counteracting the subcells. The reason for this effect – absorption of photons intended for GaAs subcell in the tunnel diode located between GaInP and GaAs sub-cells.
Мемристоры на основе полипараксилилена на гибких подложках
Authors: Швецов Б.С. , Мацукатова А.Н. , Миннеханов А.А. , Несмелов А.А. , Гончаров Б.В. , Лапкин Д.А. , Мартышов М.Н. , Форш П.А. , Рыльков В.В. , Демин В.А. , Емельянов А.В.
Published: October 2019

This work presents the results of the fabrication and investigation of flexible memristive structures based on parylene layers, which demonstrate stable resistive switching and are resistant to bends up to 10 mm radii. It is also proposed a two-step scheme for establishing the resistive state of the memristive structure, based on control of the value of the limiting current flowing through the structure. Obtained results open the possibility of using memristive structures based on parylene layers for neuromorphic computing systems and biocompatible "wearable" electronics.
Применение метода многочастотного допплеровского обратного рассеяния для исследования альфвеновских мод в токамаке
Authors: Буланин В.В. , Гусев В.К. , Курскиев Г.С. , Минаев В.Б. , Патров М.И. , Петров А.В. , Петров Ю.В. , Яшин А.Ю.
Published: October 2019

The results of the study of toroidal Alfven modes (TAE) using the multi-frequency Doppler backscattering (DBS) in the Globus-M tokamak are presented. The article is focused on the presentation of the Alfven mode registration method for multichannel probing. The possible causes of the observed oscillations of the poloidal plasma rotation velocity at the Alfvén oscillation frequencies are discussed in detail. The data on the spatial distribution of Alfvén modes revealed by multi-frequency DBS are given. The recommendations for the further development of the DBS with the aim of a more detailed study of TAE in tokamaks were determined.