bluuebunny/crossref_metadata_2025_split huggingface dataset:
The scalable production of high-quality nanographite by organic radical-assisted electrochemical exfoliation.
Authors: Grushevski E , Savelev D , Mazaletski L , Savinski N , Puhov D 
Published: December 2021

Abstract
One of the promising ways to produce graphene is the technology of graphite splitting or exfoliation, both by physical or mechanical and chemical, including electrochemical methods. The product of electro exfoliation is nanographite, which is transformed into multigraphene at the subsequent stage of liquid-phase mechanical and ultrasonic disintegration. This approach demonstrates a successful method of obtaining multigraphene from available graphite raw materials. Since, already at a potential of 1.23V, during the electrolysis of water on a graphite anode, the hydroxyl anion is discharged with the formation of a very active hydroxyl radical oxidizer, it is not surprising that when the graphite electro exfoliation process is overvolted at 10V, graphite oxidation products are formed. In order to control the defectiveness of the graphene lattice by oxidation products, we carried out processes of graphite exfoliation in the presence of both a number of reducing agents ascorbic acid, sodium borohydride, hydrazine hydrate, and in the presence of industrial antioxidants radical traps (2,2,6,6-tetramethylpiperidine-1-il)oxyl (TEMPO), (2,2,6,6-tetramethyl-4 oxo-piperidine-1-yl)oxyl (IPON), a mixture of 5,8,9-bis isomers[(2,2,6,6-tetramethyl - 4 oxo-piperidine-1-yl)]-{5,8,9-[1,1’- bi(cyclopentylidene)]-2,2’,4,4’- tetraene}(YARSIM-0215). It should be noted, that the best result of preventing the oxidation of nanographite in electro exfoliation technology in our studies is the ratio of carbon to oxygen (C/O) about 69.
Laser sintering of oxidized copper nanoparticles deposited by dry aerosol printing
Authors: Kornyushin D V , Efimov A A , Buchnev A I , Kameneva E I , Ivanov V V 
Published: December 2021

Abstract
Sintering of oxidized copper nanoparticles arrays in the form of lines by the local treatment of laser radiation with wavelengths of 527 nm and 980 nm was studied. To form lines with a width equal to 40–150 μm and a thickness equal to 0.5–4 μm focused aerosol jets with average nanoparticle sizes of 110 and 65 nm were used. The production of semiconductor arrays from oxidized copper nanoparticles with a specific electrical resistance of 2⋅10−3 Ω⋅m using laser radiation with a wavelength of 980 nm was demonstrated.
ZnO nanorods coating modified with AgInS2 quantum dots
Authors: Ryabko A A , Korepanov O A , Bobkov A A , Aleksandrova O A , Moshnikov V A 
Published: December 2021

Abstract
This paper presents the effect on the visible light photoresponse caused by the modification of ZnO nanorod coating with colloidal AgInS2 quantum dots. The modification of ZnO nanorods by immersion in colloidal solution results in the enhancement of visible absorption and photoresponse. Obtained results indicate the possibility of local heterojunctions between ZnO and AgInS2.
Structural properties of TiO2-SnO2 thin films prepared by new pyrolysis solid-phase method
Authors: Volkova M G , Storozhenko V Yu , Petrov V V , Bayan E M 
Published: December 2021

Abstract
Nanoscale TiO2-SnO2 films with the Ti:Sn ratio 1:99, 3:97 and 5:95 mol%, respectively, were obtained by solid-phase low-temperature pyrolysis method. The synthesized materials were studied by X-ray phase analysis and scanning electron microscopy (SEM) analysis. Regardless of the modified agents’ concentration, the structure of cassiterite was observed for all synthesized materials. When studying the effect of synthesis parameters on the materials properties, it was shown that both an increase in the Ti4+ concentration and in the calcination temperature leads to an increase in the particle size.
Crystallization of Bi-substituted iron garnet bi-layers
Authors: Mikhailova T V , Vysokikh Yu E , Shaposhnikov A N , Berzhansky V N , Krasnoborodko S Yu , Lutovinov A S , Bulatov M F , Churikov D V 
Published: December 2021

Abstract
Magneto-optical (MO) structures are widely used for different application in the fields of magnetoplasmonics, magneto-optics, photonics e.t.c. Bi-substituted iron garnet (Bi:IG) is high-performance MO material. Integration of Bi:IG films to silicon semiconductor technology gives new opportunities to create nanoscale hight performance MO devices. Vacuum sputtering deposition allows to fabricate Bi:IG structures on different substrate types. Authors investigate crystallization process of Bi:IG bi-layers in a different process parameter (different layers composition and its thickness, temperature and time of annealing) using gadolinium gallium garnet GGG and fused quartz SiO2 substrates to determine dependences which impact on crystallization.
Development of epitaxial PbS layers obtaining method for photoelectric transducers
Authors: Zinchenko T O , Pecherskaya E A , Volik A V , Timohina O A , Alexandrov V S , Antipenko V V 
Published: December 2021

Abstract
Photoelectric transducers are a semiconductor device that converts photonic energy into electrical energy. This paper describes obtained by the hotwall epitaxy method epitaxial PbS layers technology. Materials, methods, technological parameters of synthesis were selected and substantiated. A theoretical model of the p-n transition has been developed. The calculation of the main parameters has been done. The hotwall epitaxy method was chosen for the synthesis, because it allows to obtain layers with required properties in a single technological cycle with an economical consumption of material. BaF2 was chosen as the substrate, because in this case a smaller difference in the identity periods and the layer and the substrate thermal expansion coefficients is achieved.
Optical and structural properties of the GaAs heterostructures grown using AlGaAs superlattice buffer layer on compliant Si(100) substrates with the preformed porous-Si (por-Si) layer.
Authors: Zolotukhin D , Seredin P , Lenshin A , Goloshchapov D , Hudyakov Y , Radam Ali O , Arsentyev I , Leiste H 
Published: December 2021

Abstract
360 nm and 700 nm thick GaAs layers were grown by MO MOCVD growth technique directly on compliant Si (100) substrate and on supper-lattice (SL) AlGaAs buffer layer. The XRD study revealed better structural quality for the sample grown on SL / por-Si buffer. AFM study revealed a smoother sample surface with blocks of more regular rectangular shape and larger size as well. Photoluminescence spectra of the samples revealed an energy shift of PL maximum intensity for both samples. Sample grown on SL buffer also showed higher PL intensity corresponding to better crystalline perfection.
Graphene two terminal detector as THz mixer
Authors: Gazaliev A Sh , Moskotin M V , Belosevich V V , Rybin M G , Gayduchenko I A , Goltsman G N 
Published: December 2021

Abstract
The growing requirements for mobile communication networks (data transfer rates over 100 Gbps) makes it necessary to use carrier signal with a frequency of at least 100 GHz. This requires the development of cheap and broadband sub-terahertz (sub-THz) detectors. Here we report on our recent efforts toward the development of a heterodyne sub-THz detector based on a single layer graphene two-terminal device integrated with a bowtie antenna on a sapphire substrate. Our detector operates at frequency of 140 GHz, which corresponds to the maximum transmission of THz radiation in the Earth’s atmosphere. The heterodyne detection is achieved by quasi-optical coupling of signals from two sub-THz radiation sources to the same detector. The measured frequency bandwidth is 5.8 GHz.
Piezoelectric response of aligned carbon nanotubes depending on sublayer material
Authors: Il’ina M V , Il’in O I , Osotova O I , Rudyk N N , Ageev O A 
Published: December 2021

Abstract
The results of experimental studies of the effect of the sublayer material on the piezoelectric response and sensitivity to mechanical deformations of aligned carbon nanotubes (CNTs) are presented. It is shown that the highest piezoelectric response (136 nA at a pressing force of 4 μN) and best sensitivity are demonstrated by CNTs grown on a Mo sublayer. This dependence is probably due to the geometric parameters of CNTs and the structure of the CNT array as a whole. The results obtained can be used to develop energy-efficient nanogenerators based on CNT arrays.
Computer simulations of solar cells based on silicon/boron phosphide selective contacts
Authors: Kiyanitsyn S Y , Gudovskih A S 
Published: December 2021

Abstract
Silicon solar cells with selective contacts based on boron phosphide (BP) demonstrate a high potential according to simulation. However, the influence of defects created at the BP/Si interface during BP deposition is a critical issue for solar cell performance. The computer simulations were performed to understand how the defects in the near-surface region and at the interface affect the photovoltaic properties. Calculations of the dependence of the characteristics of solar cells on parameters such as the density of interface states, the concentration of defects in the near-surface region, and its width were made.
Study of GaP/Si electron-selective contact deposited by plasma
Authors: Maksimova A A , Baranov A I , Uvarov A V , Gudovskikh A S , Kudryashov D A , Morozov I A , Bogdanova M V 
Published: December 2021

Abstract
The article is based on an important characterization task to accurately evaluate the properties of the layers, their interfaces with c-Si, and to select the best candidates to integrate them into a c-Si-based solar cell. The work has shown that GaP could be doped with n-type doping, thus providing a selective contact for the electrons, and has a significant valence band offset with c-Si, making it an excellent candidate as a selective contact, without requiring an additional ITO layer.
QKD key generation control protocol
Authors: Rudavin N V , Gerasin I S , Mekhtiev E E , Duplinsky A V , Kurochkin Y V 
Published: December 2021

Abstract
Polarization-encoding fiber QKD requires compensation of polarization distortion caused by birefringence in optical fiber. Solving this task inevitably requires losing some effectiveness in terms of the final key rate. In this work, a time-division multiplexing protocol for polarisation calibration is suggested. This protocol was implemented in a QRate commercial QKD fiber system, utilizing BB84-protocol. Parameters of the protocol were optimized to maximize the secret key rate.
Several processes participating in a decrease and the droop of external quantum efficiency in green InGaN/GaN MQW structures
Authors: Talnishnikh N A , Shabunina E I , Shmidt N M , Ivanov A E 
Published: December 2021

Abstract
The obtained experimental results allow us to clarify the nature of mechanisms related to the presence of cations in disordered InGaN alloy and hetero-interfaces. The capture of charge carriers by cations reduces the external quantum efficiency (EQE) in green MQWs at j < 10 A/cm2. The EQE droop phenomenon caused by smoothed out lateral potential fluctuations occurs at j > 10 A/cm2. At j > 40 A/cm2 the droop associated with interactions between charge carriers and dislocations and grain boundaries takes place.
The study of molecular composition in biomimetic interface of biocomposite/dentin
Authors: Goloshchapov D , Kashkarov V , Ippolitov I , Ippolitov Yu , Nikitkov K , Vongsvivut J , Seredin P 
Published: December 2021

Abstract
The aim of the study is the problem of formation of the biomimetic interface between the dental product and dentin of the human tooth as well as the investigations of molecular-chemical features in biointerface with the use of molecular multivariate IR-visualization. The data on synchrotron IR-mapping made enabled to differentiate the regions of sound dentin tissue and biomimetic transition layer and also to determine molecular groups responsible for the process of integration.
Optical properties of plasmonic metal nanoparticles on GaN surface
Authors: Alay P , Enns Y , Kazakin A , Mizerov A , Nikitina E , Kondrateva A , Vyacheslavova E , Karaseov P , Mishin M 
Published: December 2021

Abstract
Effect of the plasmonic resonant absorption in metal nanoparticles formed on the GaN surface on optical properties of samples is studied. Silver and gold nanoparticles are formed by solid-state dewetting on epitaxial GaN grown by molecular beam epitaxy (MBE) on c-sapphire substrate. Theoretical and experimental optical characteristics show the appearance characteristic absorption of the surface plasmon resonance. The results of the work show the possibility of increasing the efficiency of GaN-based optoelectronic devices.
Fiber Optic Attenuator
Authors: Andreev D P , Andreeva E I 
Published: December 2021

Abstract
A study of a bending-type fiber-optic attenuator has been carried out. It is shown that the use of G.655 - optical fiber provides the largest dynamic range of the attenuator. The spectral dependence of the bending losses was measured in a wide range of wavelengths: from 1270 to 1610 nm.
Unambiguous state discrimination and joint measurement attacks on passive side channel of the light source in BB84 decoy-state protocol
Authors: Babukhin D , Sych D 
Published: December 2021

Abstract
Quantum key distribution (QKD) has a promise of unconditionally secure communication between the remote sides. The real-world QKD implementations, however, have numerous loopholes, both of engeneering and physical origin, and compromise the security promise. In this work, we investigate two attack strategies on the passive side channel of the light source along with the optimal cloning attack on the BB84 protocol with decoy-states. We calculate an upper bound of a secret key rate for these situations and show that the joint measurement attack on the signal and side channel degree of freedom is more effective to the adversary.
Stellar calibration of the single-photon receiver for satellite-to-ground quantum key distribution
Authors: Khmelev A V , Duplinsky A V , Kurochkin V L , Kurochkin Y V 
Published: December 2021

Abstract
Satellite quantum communication is the technology that allows to deploy large-scale quantum networks with a communication range of thousands kilometres We report the ground receiver for downlink quantum key distribution (QKD) with satellite. An optical part of this system including an active tracking loop is mounted on a 600-mm Ritchey-Chretien telescope and permits to distinguish polarization states to perform QKD between ground and satellite. Moreover, a procedure of calibration the receiver using stars with known brightness is presented. Measurements of the photon count rate of stars in the spectral range of 845 nm - 855 nm are performed and compared with an estimate.
Features of the fiber-optics data system using optical solitons
Authors: Ermolaev A A , Shevchenko M A , Andreeva E I 
Published: December 2021

Abstract
The analysis of the parameters of a high-speed information data system using dispersion-managed solitons is carried out. It is shown that the quality of information transmission can be increased by choosing the input-output point of the symbol sequence on the dispersion map.
Simulation of the photonic nanojet effect for Raman scattering enhancement in the diagnostics of oxide films
Authors: Ivanina A I , Agafonova D S , Roshina N V , Lamkin I A 
Published: December 2021

Abstract
In this paper, by means of numerical simulations in the COMSOL Multiphysics software it’s demonstrated that Raman scattering enhancement can be achieved for the diagnosis of metal oxide films using spherical particles made of barium titanate with a 10-micron diameter sphere. The formation of photonic nanojet in the sphere/film/substrate system at different radiation wavelengths and microsphere refractive index, film, and substrate was studied. The optimal interval of the particle refractive index is n≈1.8-2 was determined, at which the gain occurs directly at the particle/film interface. It is shown that for the UV wavelength range of wavelengths and film thicknesses from 50 to 200 nm, the gain is maximum. For ZnO and PZT films in the perovskite phase, sitall and quartz are preferred as the substrate material, while for PZT in the pyrochlore phase, sapphire is preferred.
Thermo-optical properties of nanophotonic devices with carbon nanotube films
Authors: Komrakova S , An P , Kovalyuk V , Golikov A , Gladush Y , Mkrtchan A , Nasibulin A , Goltsman G 
Published: December 2021

Abstract
Here, thermo-optical properties of hybrid nanophotonic circuits SWCNTs/SiN were investigated by studying the temperature dependence of the resonance wavelengths. After experimental and theoretical study, we found the thermo-optical coefficient of SWCNTs film is equal to 2.02 10-6 RIU/0C.
Polarization-sensitive terahertz spectroscopy of graphene nanostructures
Authors: Kvitsinskiy A , Rybin M , Zaitsev A , Bogdanov K , Zykov D , Obraztsova E 
Published: December 2021

Abstract
Efficient devices for control temporal and spatial properties of electromagnetic waves are essential for the development of terahertz (THz) technologies. But despite the great progress achieved in a study of graphene, the influence of the number of graphene layers on its optical and electrical properties in the THz frequency range has not yet been sufficiently studied. In this work, we experimentally studied optical and electrical properties of multilayer graphene (MLG) thin films in the frequency range 0.2–0.8 THz (corresponding to a wavelength range ∼1.5–0.37 mm), at a controlled room temperature of 291 K, and a relative humidity of 40 %. Using our custom-made THz time-domain spectroscopic polarimetry system, we obtained spectra of the complex relative permittivity and the electrical conductance of the chemical vapor deposition graphene with ∼14, ∼40, and ∼76 layers of graphene on borosilicate glass substrates. It is shown that the conductance increases nonlinearly with an increase in the graphene layer number and reaches, for ∼76 layers, 0.06 S for the real, and 0.03 S for the imaginary part, respectively. Our results show that by using MLG it is possible to create tunable devices that can be used in the advanced areas of THz photonics.
Control of the mode composition of optical radiation in a microstructured fiber
Authors: Pchelkin G A , Fadeenko V B , Davydov V V , Rud V Yu 
Published: December 2021

Abstract
The construction structure of microstructured fibers is considered. A research scheme of the mode composition and defects control in optical fibers is developed. A microstructured fiber for studying optical vortex fields has been developed and manufactured. The results of studies of the same fiber structure and the distribution of optical radiation depending on the parameters of the technological cycle of its production are presented.
Absorption properties of bromide photo-thermo-refractive glasses doped with Ytterbium
Authors: Pesnyakov V , Kharisova R , Ignatiev A 
Published: December 2021

Abstract
In this work bromide photo-thermo-refractive glasses with different Ytterbium concentration were explored. It is shown that UV irradiation and subsequent heat treatment of samples with Yb 2 mol.% causes significant red-shift absorption line from 410 nm with temperature lower than Tg to 517 nm with temperature Tg +60 °C. For small concentration of Yb (0,1 mol. %) maximum red-shift in plasmon resonance absorption band is shown as 485 nm and it is the same for heat treatment temperatures from Tg +20 °C to Tg +60 °C.
Development of a fiber-optic system for testing instruments for monitoring nuclear power plants
Authors: Pilipova V M , Davydov V V , Rud V Y 
Published: December 2021

Abstract
The necessity of testing the equipment for monitoring the operation of nuclear power plants is justified. It is proposed to use optical fiber and pulsed laser radiation for these purposes. It is established that optical fiber is more resistant to radiation than other communication systems. The design of a fiber-optic emergency simulator is developed. The calculation of its characteristics is carried out. Their experimental research was carried out. It was found that with an optical signal delay of 98.6 microseconds, the loss is – 26 dB with an uneven frequency response of ± 2 dB. This makes it possible to test the entire set of equipment that uses optical signals used to control a nuclear power plant.
Helical phase in two-dimensional magnets due to four-spin interactions
Authors: Rakhmanova G R , Ilin D I , Osipov A N , Shushakova I V , Iorsh I V , Ado I A , Titov M 
Published: December 2021

Abstract
We demonstrate that in ferromagnets with the D3h point group of symmetry a possible origin of phase transition from a collinear ferromagnetic state to a non-collinear state can be the fourth order contributions to the free energy density that are allowed by this point group of symmetry. At the same time, Dzyaloshinskii-Moria interaction vanishes in such materials. Via symmetry analysis we derive seven possible fourth order contributions to the free energy density with respect to the unit vector of the local magnetization direction but only two of them can be considered as independent. Moreover, for two-dimensional systems only one survives. Considered symmetry class is essential because a large group of two-dimensional intrinsic ferromagnets belongs to it, for example a monolayer Fe3GeTe2. The four-spin chiral exchange does also manifest itself in peculiar magnon spectra and favors spin waves.
The investigation of the features optical vortices focusing by ring gratings with the variable height using high-performance computer systems
Authors: Savelyev D A 
Published: December 2021

Abstract
The diffraction of vortex laser beams with circular polarization by ring gratings with the variable height was investigated in this paper. Modelling of near zone diffraction is numerically investigated by the finite difference time domain (FDTD) method. The changes in the length size of the light needle and focal spot size are shown depending on the type of the ring grating.
Investigation of laser and thermal sintering processes of silver nanoparticles agglomerates synthesized by spark discharge
Authors: Tikhonov S S , Nouraldeen M , Khabarov K M , Efimov A A , Ivanov V V 
Published: December 2021

Abstract
Changes in the shape and size of silver nanoparticles (NPs) during their laser and thermal sintering have been studied experimentally and theoretically. Aerosol silver NPs forming dendrid-like agglomerates 180 nm in size were synthesized by spark discharge and exposed to laser radiation and high temperature of 750 °C. The shape and size of the NPs were investigated depending on the power of the laser radiation and the temperature of the gas. It is estimated that, at a power density of laser radiation of the order of 103-104 W/cm2, the formation of spherical NPs with an average size of 140 nm is expected. Such particles turn out to be similar to NPs thermally heated in a gas flow at 750 °C for 6 seconds.
Tunable laser induced periodic surface structures in Ge2Sb2Te5 thin films
Authors: Bessonova Irina G , Trofimov Pavel I , Lazarenko Petr I , Kirilenko Demid A , Bert Nikolay A , Kozyukhin Sergey A , Sinev Ivan S 
Published: December 2021

Abstract
Planar photonic structures, such as gratings and metasurfaces, are routinely used for beam steering, waveguide coupling, and light localization. However, conventional fabrication techniques that involve lithography are demanding in terms of time and cost. Much cheaper and simpler methods for surface patterning and formation of periodic surface structures are enabled by direct laser processing. Here, we demonstrate low-cost rapid fabrication of high-quality phase gratings based on the formation of laser induced periodic surface structures (LIPSS, or ripples) in Ge2Sb2Te5 (GST) thin films. Due to unique phase change properties of GST, the structures demonstrate strong modulation of refractive index with period controlled by the wavelength of laser irradiation. We study the formation of phase change LIPSS in a broad range of excitation wavelengths and observe transition between regimes with different orientations of generated ripples with respect to laser polarization.