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Лебедев-Степанов, Петр Владимирович

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Институт нанотехнологий в электронике, спинтронике и фотонике

Институт ИНТЭЛ занимается научной деятельностью и подготовкой специалистов в области исследования физических принципов, проектирования и разработки технологий создания компонентной базы электроники гражданского и специального назначения, а также построения современных приборов на её основе. Наша основная цель – это создание и развитие научно-образовательного центра мирового уровня в области наноструктурных материалов и устройств электроники, спинтроники, фотоники, а также создание эффективной инновационной среды в области СВЧ-электронной и радиационно-стойкой компонентной базы, источников ТГц излучения, ионно-кластерных технологий материалов.

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Лебедев-Степанов

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Петр Владимирович

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Теперь показываю 1 - 10 из 19

Только метаданные
Self-Assembly of Fluorescent Photonic Crystal Structures in Binary Water-Glycerol Solvent Droplets
(2020) Savenko, O. A.; Stepko, A. S.; Shevchenko, N. N.; Koshkin, A. V.; Lebedev-Stepanov, P.; Лебедев-Степанов, Петр Владимирович
The morphology of photonic-crystal structures formed by the self-assembly of fluorescent marker nanoparticles from evaporating droplets of a binary water-glycerol solvent, the components of which differ appreciably from each other in the viscosity and evaporation rate, being infinitely mutually soluble under normal conditions, was has been studied experimentally for the first time. It has been shown that the main self-assembly disordering factor is Marangoni vortex flows, and the change in the initial concentration ratio between binary mixture components enables the control over the degree of disordering in the solid phase, which is formed after the solvent is evaporated from a droplet and distributed over the substrate. A low initial concentration of any component corresponds to the most ordered distribution, whereas their medium concentrations correspond to the most disordered distribution. The characteristic values of Marangoni numbers in experiments have been calculated. It has been demonstrated that the average radius of the distribution of an ensemble of marker particles over a substrate may serve as a descriptor for the degree of ordering.
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The Role of Integrated Approach in the Determination of Nanoparticle Sizes in Dispersions
(2022) Kuznetsova, E. V.; Kuznetsov, N. M.; Kalinin, K. T.; Novikov, A. A.; Lebedev-Stepanov, P. V.; Лебедев-Степанов, Петр Владимирович
Только метаданные
Evaporation of Small Sessile Drop Deposited on a Horizontal Solid Surface: New Exact Solutions and Approximations
(2024) Lebedev-Stepanov, P. V.; Savenko, O.; Лебедев-Степанов, Петр Владимирович
Evaporating a liquid sessile drop deposited on a horizontal surface is an important object of applications (printing technologies, electronics, sensorics, medical diagnostics, hydrophobic coatings, etc.) and theoretical investigations (microfluidics, self-assembly of nanoparticles, crystallization of solutes, etc.). The arsenal of formulas for calculating the slow evaporation of an axisymmetric drop of capillary dimensions deposited on a flat solid surface is reviewed. Characteristics such as vapor density, evaporation flux density, and total evaporation rate are considered. Exact solutions obtained in the framework of the Maxwellian model, in which the evaporation process of the drop is limited by vapor diffusion from the drop surface to the surrounding air, are presented. The summary covers both well-known results obtained during the last decades and new results published by us in the last few years, but practically unknown to the wider scientific community. The newest formulas, not yet published in refereed publications, concerning exact solutions for a number of specific contact angles are also presented. In addition, new approximate solutions are presented (total evaporation rate and mass loss per unit surface area per unit time in the whole range of contact angles Оёв€€[0, ПЂ), drop lifetime in constant contact radius evaporation regime and constant contact angle mode), which can be used in modeling without requiring significant computational resources.
Только метаданные
Quasi-Stationary Evaporation of a Small Liquid Droplet on a Flat Substrate: Analytical Solution in Bipolar Coordinates
(2022) Savenko, O. A.; Lebedev-Stepanov, P. V.; Лебедев-Степанов, Петр Владимирович
Только метаданные
Specific Solvation of a 4-DASPI Dye in a Water–Ethylene Glycol Binary Solvent
(2022) Stepko, A. S.; Medvedeva, A. A.; Koshkin, A. V.; Lebedev-Stepanov, P. V.; Лебедев-Степанов, Петр Владимирович
Abstract: The solvatochromic shifts of the maxima of the absorption spectra of a 4-DASPI dye (4-[4-(dimethylamino)styryl]-1-methylpyridinium iodide) in a water–ethylene glycol binary solvent in a range of concentrations of 0–100% are experimentally studied. The dependence of the solvatochromic shift on the macroscopic permittivity (dielectric constant) of the solution and concentration of ethylene glycol is constructed. The Onsager–Liptay model is applied for the theoretical interpretation which makes it possible to estimate the effective permittivity in the microscopic region directly adjacent to the chromophore based on the values of the measured solvatochromic shifts. It is found that the value of the permittivity in the solvate shell of this dye substantially differs from the macroscopic value of this quantity, which means that the shell is significantly enriched with ethylene glycol (specific solvation) throughout the entire range of concentrations, and the enrichment reaches a maximum approximately in the middle of the specified range. The composition of the solvate shell of the dye at different values of the concentration is discussed. © 2022, Pleiades Publishing, Ltd.
Только метаданные
Parametric Broadening of the Electronic-Vibrational Spectrum of a Molecule Caused by Zero-Point Vibrations and Thermal Fluctuations of Interatomic Bonds
(2021) Lebedev-Stepanov, P. V.; Лебедев-Степанов, Петр Владимирович
© 2021, Pleiades Publishing, Ltd.Abstract: The existence in the Born–Oppenheimer approximation of a fundamentally new type of broadening of the spectral line of the electronic vibrational–rotational (rovibronic) transition in a molecule, caused by zero-point vibrations and thermal fluctuations of atomic nuclei near their equilibrium positions during vibrational–rotational motion inside the molecule, is discovered. A quantitative description in the harmonic approximation is obtained to describe the shape and width of the electron transition line corresponding to this type of broadening, which is called parametric, since the energy of any rovibronic level and transition between levels depends parametrically on the current instantaneous position of nuclei, which move much more slowly than electrons. To take this effect into account, Franck-Condon diagrams with oblique (bent) levels of vibrational energy are proposed. From the point of view of the Copenhagen interpretation of quantum mechanics, the parametric broadening exists due to the difference between an open (i.e. experimentally measured) quantum system from an isolated (unobservable) one. The magnitude of this broadening is estimated on the example of the 0–0 transition in a series of polymethine dye monomers. The estimate showed that the magnitude of the parametric broadening of the indicated zero-phonon line is comparable with the broadening observed in the experiment. The existing quantum chemical methods for calculating molecular spectra do not take into account the parametric broadening. They smooth the quasi-continuum of closely spaced rovibronic transitions, approximately calculating their common envelope, but do not consider the broadening of a single transition. The creation of a theory of parametric broadening will contribute to the development of intramolecular converters of energy from nuclei to electrons and vice versa, sensing nanoprobes, and quantum radio, photoacoustic and acousto-optic, and transceiving or converting devices of molecular size.
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Computation of dielectric properties of nano-probe local surroundings by solvatochromic spectral shift measurement of organic dye molecule
(2019) Stepko, A. S.; Lebedev-Stepanov, P. V.; Лебедев-Степанов, Петр Владимирович
© Published under licence by IOP Publishing Ltd. Study of dielectric properties of the macrocyclic molecules cavity that can form inclusion complexes with dye molecules is an important problem. Changes in absorption spectra of chromophore inserted into macrocyclic cavity with the formation of the supramolecular complex can be considered as solvatochromic shift. This shift caused by changes of dielectric properties of the environment around the chromophore when it moves from water solution to macrocyclic cavity. Theoretical model that can describe the effective dielectric permittivity of the cavity allows predicting solvatochromic spectral shift of dye molecules due to non-covalent supramolecular complexation. Such a dye molecule could apply as a nano-probe for measurement of the effective dielectric constant of any local surrounding media in which its chromophore can be inserted.
Только метаданные
Microstructure and Rheological Behavior of Stabilized Gold Nanoparticles Hydrosol
(2021) Kamyshinsky, R. A.; Kuznetsov, N. M.; Stepko, A. S.; Chvalun, S. N.; Lebedev-Stepanov, P. V.; Лебедев-Степанов, Петр Владимирович
© 2021, Pleiades Publishing, Inc.Abstract: A comprehensive analysis of an aqueous solution of gold nanoparticles with an average size of 6 nm in a citrate buffer has been carried out, with investigation of the solution rheology and structure by electron and atomic force microscopy. A deviation of the rheological behavior of hydrosol from the Newtonian properties is found even at low gold nanoparticle concentrations. The specific features of the rheological behavior of hydrosol are explained based on the transmission electron microscopy (TEM) data.
Только метаданные
Electron Emission Properties of Self-Assembling Nanodiamond‒Polymer Nanocomposite Coatings
(2019) Dideykin, A. T.; Chvalun, S. N.; Vasiliev, A. L.; Grigoryev, T. E.; Lebedev-Stepanov, P. V.; Лебедев-Степанов, Петр Владимирович
© 2019, Pleiades Publishing, Inc.Abstract: The formation of thin-film coatings from detonation nanodiamond (DND) suspensions on atomically ordered conducting Ni–W substrates by self-assembly in an evaporating aqueous solution using the spin coating technique has been investigated. It is shown that, in the absence of a polymer matrix, the DND distribution over the substrate is nonuniform and the adhesion to the substrate is weak, which prevents obtaining a uniform and stable emission current. The use of DND–water-soluble polymer (chitosan and carrageenan polysaccharides, polyacrylic acid, and sulfonated polyaniline (SPANI)) coatings makes it possible to enhance the film adhesion to the substrate and provide a disaggregated state of nanocrystallites. The DND–SPANI coatings have demonstrated the best emission characteristics. Based on the analysis of the emission characteristics, a new model of emission center in the DND–polymer–substrate system has been proposed.
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Study of the 3D Structure of a Hydrogel with Gold Nanoparticles by Cryogenic Electron Microscopy
(2022) Mikhutkin, A. A.; Kamyshinsky, R. A.; Kuznetsov, N. M.; Lebedev-Stepanov, P. V.; Stepko, A. S.; Vasiliev, A. L.; Лебедев-Степанов, Петр Владимирович
A hydrogel with gold nanoparticles stabilized in a citrate buffer is obtained by dehydration from a solution (sol-gel transition). The morphological characteristics of the hydrogel are studied using cryogenic transmission electron microscopy, in particular cryoelectron tomography. The spatial structure of the hydrogel is studied in three dimensions. The dimensional parameters of the nanoparticles and distances to nearest neighbors are determined. It is found that most of the nanoparticles are in a bound state and form clusters in the process of hydrogel formation. © 2022, Pleiades Publishing, Ltd.