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Your search keyword '"Orekhov, Andrey"' showing total 4 results
Start Over Author "Orekhov, Andrey" Publisher american institute of physics
4 results on '"Orekhov, Andrey"'

1. Criterion for estimation of stress-deformed state of SD-materials.

Author

Orekhov, Andrey V., Kustova, Elena, Leonov, Gennady, Morosov, Nikita, Yushkov, Mikhail, and Mekhonoshina, Mariia

Subjects
*MONOTONIC functions, *REAL variables, *MATHEMATICAL sequences, *MATHEMATICAL analysis, *PARABOLIC operators
Abstract

A criterion is proposed that determines the moment when the growth pattern of the monotonic numerical sequence varies from the linear to the parabolic one. The criterion is based on the comparison of squares of errors for the linear and the incomplete quadratic approximation. The approximating functions are constructed locally, only at those points that are located near a possible change in nature of the increase in the sequence. [ABSTRACT FROM AUTHOR]

Published
2018
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2. Superionic Conductor PbSnF4 in the Inner Channel of SWNT.

Author

Zakalyukin, Ruslan Mikhalovich, Levkevich, Ekaterina Alexandrovna, Kumskov, Andrey Sergeevich, and Orekhov, Andrey Sergeevich

Subjects
*NANOCOMPOSITE materials, *FLUORIDES, *IONS, *NANOSTRUCTURED materials, *X-ray diffraction, *SCANNING transmission electron microscopy
Abstract

The nanocomposite PbSnF4@SWNT was obtained by capillary technique for the first time. This nanocomposite was investigated using X-ray diffraction phase analysis (XRD), high-resolution transmission electron microscopy (HRTEM) and scanning transmission electron microscopy (STEM), energy-dispersive X-ray spectroscopy (EDX). SWNT diameter is ~2 nm. Lead tetrafluorostannate (PbSnF4) monoclinic modification (space group P2/n) was identified by XRD analysis. The periodicity of the crystal plane (201) along the tube axis is ~3.2Å. The distortion of plane is 11° with respect to the nanotube axis. The model of PbSnF4 single crystal contains ~168 atoms. The structure of 1D PbSnF4@SWNT nanocomposite and HREM image were modelled. [ABSTRACT FROM AUTHOR]

Published
2018
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3. Highly oriented graphite produced by femtosecond laser on diamond.

Author

Kononenko, Vitali V., Khomich, Andrej A., Khomich, Alexander V., Khmelnitskii, Roman A., Gololobov, Viktor M., Komlenok, Maxim S., Orekhov, Andrey S., Orekhov, Anton S., and Konov, Vitaly I.

Subjects
*FEMTOSECOND lasers, *PYROLYTIC graphite, *GRAPHITE, *DIAMONDS, *TRANSMISSION electron microscopy, *SCANNING electron microscopy
Abstract

To transform a monocrystalline diamond into monocrystalline graphite, the exposure of an ultrafast laser to a (111) diamond face was investigated for the first time. The single pulse of the third harmonic of a Ti:sapphire laser (100 fs, 266 nm) was used to produce graphitized inclusions embedded in a (111) diamond substrate. Three different regimes of (111) diamond graphitization are discussed in this paper. Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy were used to investigate the graphitized material, which was found to resemble highly oriented graphite at certain laser fluencies. The proposed approach to the problem of perfect local diamond graphitization is an important step toward creating all-carbon composite systems consisting of conductive and dielectric phases. [ABSTRACT FROM AUTHOR]

Published
2019
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4. Field emission from single-walled carbon nanotubes modified by annealing and CuCl doping.

Author

Kleshch, Victor I., Tonkikh, Alexander A., Malykhin, Sergey A., Redekop, Eugene V., Orekhov, Andrey S., Chuvilin, Andrey L., Obraztsova, Elena D., and Obraztsov, Alexander N.

Subjects
*FIELD emission, *SINGLE walled carbon nanotubes, *COPPER chlorides, *ANNEALING of metals, *DIODES
Abstract

In this article, we present a comparative study of field emission (FE) properties of the films of pristine, annealed and CuCl-filled single-walled carbon nanotubes (SWCNTs). The current-voltage dependencies and emission site distributions were measured in the diode configuration with a flat phosphor-coated anode. A significant increase of the threshold field was observed after annealing and doping of the films. It was explained by the selective oxidation of the small-diameter nanotubes confirmed by the Raman spectroscopy. The FE properties of annealed and filled SWCNTs were found to coincide with each other. At the same time, their Raman spectra differ significantly indicating the strong p-type doping induced by encapsulated CuCl. The obtained result reveals that the CuCl filling leads to significant changes in macroscopically averaged electronic properties but do not change the local work function at the apexes of emitting nanotubes, which is important for the further development of SWCNTs-based FE cathodes. [ABSTRACT FROM AUTHOR]

Published
2016
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