المؤلفون: Starchikov, S. S., Zayakhanov, V. A., Troyan, I. A., Bykov, A. A., Bulatov, K. M., Vasiliev, A. L., Perekalin, D. S., Snegirev, N. I., Kulikova, E. S., Davydov, V. A., Lyubutin, I. S.

المصدر: JETP Letters; May2024, Vol. 119 Issue 9, p681-687, 7p

مصطلحات موضوعية: CEMENTITE, DIAMOND anvil cell, MOSSBAUER spectroscopy, LASER heating, TRANSMISSION electron microscopy, FERROCENE

مستخلص: Specific features of thermal transformations of ferrocene Fe(C5H5)2 at a pressure of 10 GPa upon laser heating to 2200 K have been investigated in diamond anvil cells. Maps of the temperature distribution on the sample during the heating have been obtained. The structure and properties of the transformation products have been studied by X-ray diffraction analysis, transmission electron microscopy, and Mössbauer spectroscopy. It is established that a characteristic feature of ferrocene transformations upon laser heating is the simultaneous formation of nanoparticles of iron (α-Fe) and iron carbide (Fe7C3) crystalline phases. The presence of α-Fe in the products of thermal transformations of ferrocene at high pressures has been observed for the first time. Possible mechanisms of the simultaneous formation of these nanoparticles during ferrocene transformations are discussed. [ABSTRACT FROM AUTHOR]

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المؤلفون: Bykov, A A, Zinin, P V, Bulatov, K M, Filonenko, V P, Kutuza, I B

المصدر: Journal of Physics: Conference Series ; volume 1556, issue 1, page 012045 ; ISSN 1742-6588 1742-6596

الوصف: A direct transformation of the sintered BC 3 phase to a novel diamond-like d -BC 3 phase was observed in a diamond anvil cell (DAC) at high temperature, 2500 K and high pressure, 22 GPa. For heating a specimen in a DAC a laser heating (LH) system combined with an acousto-optical filter and synchronized with a video camera was used. Combining the LH system with the acousto-optical filter allows measurement of the temperature distribution under infrared (1064 nm) LH of a specimen under high pressure in a DAC. The starting material with a composition BC 3 was obtained by sintering a powder of nanodiamonds with a powder of boron microparticles at 6.0 GPa during 150 s heating at 1200 °C. The quenched BC 3 specimen was studied by the Raman spectroscopy.

الإتاحة: https://doi.org/10.1088/1742-6596/1556/1/012045Test

المؤلفون: Bulatov, K M, Khramov, N A, Vinogradov, M A, Nosov, P A, Zinin, P V

المصدر: Journal of Physics: Conference Series ; volume 1636, issue 1, page 012034 ; ISSN 1742-6588 1742-6596

الوصف: In this paper, a modeling of a laser optical system for heating samples in a high-pressure cell was performed, in which the laser heating system and the optical system for measuring the temperature distribution are separated. It is shown that a setup with separate heating and temperature measurement systems allows one to: (i) adjust the optical temperature measurement system regardless of the alignment of the IR laser; (ii) obtain the optimal spot of the IR laser beam and control the beam in the future using a movable lens and an acousto-optical deflector.

الإتاحة: https://doi.org/10.1088/1742-6596/1636/1/012034Test

المؤلفون: Mantrova, Yu V, Zinin, P V, Bykov, A A, Bulatov, K M

المصدر: Journal of Physics: Conference Series ; volume 1556, issue 1, page 012054 ; ISSN 1742-6588 1742-6596

الوصف: We present the first experimental demonstration of a new imaging system for in-situ measurement the two-dimensional distribution of the effective emissivity and temperature of a heated specimen. In this work, we use the model of a gray body, assuming that the emissivity is constant over the entire wavelength range from 600 to 800 nm. Data acquisition was done using the laser heating (LH) system developed at the STC UI RAS. The LH system allows us to reach extremely high temperatures up to 6000 K at high pressures. The main component of the system is an imaging tandem acousto-optical tunable filter synchronized with a video camera. The maximal error of the emissivity measurement of the tungsten sample was found to be 13%, whereas the maximal error of the temperature measurements did not exceed 2%. An influence of different factors on the error of the emissivity determination is also discussed.

الإتاحة: https://doi.org/10.1088/1742-6596/1556/1/012054Test

المؤلفون: Mantrova, Yu V, Zinin, P V, Bykov, A A, Bulatov, K M

المصدر: Journal of Physics: Conference Series ; volume 1421, issue 1, page 012060 ; ISSN 1742-6588 1742-6596

الوصف: The aim of this report is to conduct a rigorous data analysis of the emissivity and temperature measurements on the surface of a solid specimen during laser heating (LH). Measurements of the emissivity and temperature is based on the use of a tundem acousto-optic filter (tandem acousto-optical tunable filter or TAOTF) connected with a high-resolution video camera. The set of spectral images obtained with the help of TOTF in the range of 750-800 nm makes it possible to calculate the dependence of the radiation intensity of the heated surface on the wavelength at each point of the surface. The distribution of the temperature and the emissivity of the heated body surface is obtained by fitting the experimental spectral dependence of the radiation intensity at each point of the heated object to the Planck distribution using the least squares method (LSM). A development of the mathematical analysis of the statistical errors of the emissivity determination by the LSM is described.

الإتاحة: https://doi.org/10.1088/1742-6596/1421/1/012060Test

المؤلفون: Zinin, P V, Romanov, R I, Fominski, V Yu, Filonenko, V P, Troyan, I A, Bulatov, K M, Vasil’evskii, I S, Safonov, D A, Fominski, D V, Soloviev, A A

المصدر: Journal of Physics: Conference Series ; volume 1238, issue 1, page 012008 ; ISSN 1742-6588 1742-6596

الوصف: Thin-film precursors of BC x were formed by pulsed laser codeposition of boron and carbon. Targets made of pressed boron and carbon powders with an equal element content (B/C = 1/1) and an increased carbon content (B/C = 1/3) were used. The films were deposited on sapphire substrates at elevated temperature (700°C) which determined the initial properties of the precursor BC x films. Irradiation of the films was carried out by laser pulses of nanosecond duration with varying intensity. The films obtained by laser annealing of BC x (Q-BC x ) were studied by scanning electron microscopy and micro-Raman spectroscopy. Irradiation under optimal conditions made allowed to realize pulsed melting of the films and partial preservation of their continuity on the substrate. The local structure of Q-BC x films and the nature of the changes in their electrophysical properties depended on the composition of the precursor films and the laser irradiation regimes.

الإتاحة: https://doi.org/10.1088/1742-6596/1238/1/012008Test

المؤلفون: Bykov, A A, Zinin, P V, Bulatov, K M, Khokhlov, D D, Kutuza, I B

المصدر: Journal of Physics: Conference Series ; volume 1421, issue 1, page 012031 ; ISSN 1742-6588 1742-6596

الوصف: Recently, it was shown that the use of a tandem acousto-optic tuneable filter (TAOTF) in combination with a camera allows one to measure the temperature distribution at the focus of a laser beam on an object’s surface. The TAOTF advantage is a reduction of aberrations and spatial distortions. Unfortunately, a TAOTF significantly reduces the intensity of the transmitted light beam, requires longer exposure time and often hampers temperature measurements below 1200 K. A single-crystal AOTF is free from this drawback and allows increasing the intensity of the incident radiation to the camera sensor. The paper presents experimental data for comparing measurements of the temperature distribution at the laser focus, obtained using single-crystal AOTF and TAOTF. A strong chromatic drift caused by AOTF-based system was compensated using the digital processing of the spectral images.

الإتاحة: https://doi.org/10.1088/1742-6596/1421/1/012031Test

المؤلفون: Bykov, A A, Kutuza, I B, Zinin, P V, Machikhin, A S, Troyan, I A, Bulatov, K M, Batshev, V I, Mantrova, Y V, Gaponov, M I, Prakapenka, V B, Sharma, S K

المصدر: Journal of Physics: Conference Series ; volume 946, page 012085 ; ISSN 1742-6588 1742-6596

الإتاحة: https://doi.org/10.1088/1742-6596/946/1/012085Test
http://stacks.iop.org/1742-6596/946/i=1/a=012085/pdfTest
http://stacks.iop.org/1742-6596/946/i=1/a=012085?key=crossref.93b9058bc384a9a0412a357241e44868Test

المؤلفون: Bulatov, K. M.¹ (AUTHOR), Zinin, P. V.¹ (AUTHOR) zosimpvz@mail.ru, Nosov, P. A.² (AUTHOR) pan@bmstu.ru, Khramov, N. A.² (AUTHOR)

المصدر: Instruments & Experimental Techniques. Feb2023, Vol. 66 Issue 1, p85-91. 7p.

مصطلحات موضوعية: *LASER beams, *INFRARED radiation, *TEMPERATURE distribution, *OPTICAL elements, *BEAM splitters, *INFRARED lasers

مستخلص: A new scheme of an optical system with separated channels for laser heating of a sample in a high-pressure cell and measurements of the distributions of temperature and intensity of infrared (IR) laser radiation is proposed. This separation was achieved by introducing a polarizing cubic beam splitter between the high-pressure cell and the objective of the optical system of the measuring channel. It is shown that the introduction of a beam splitter does not increase the chromatic aberrations of the optical system of the measuring channel nor does it distort the measured temperature distribution. In the scheme in the heating channel, a movable focusing lens provides a wide spot of high-power infrared laser radiation on the sample and a smaller temperature gradient. In this scheme, there is no overheating of the optical elements in the heating channel, which makes it possible to carry out a long-term effect of high-power laser radiation on the sample in high-pressure cells. [ABSTRACT FROM AUTHOR]

المؤلفون: Filonenko, V. P., Nozhkina, A. V., Romanov, R. I., Zinin, P. V., Titov, S. A., Lomonosov, A. M., Pupyrev, P. D., Bulatov, K. M., Bykov, A. A., Anokhin, A. S., Kutuza, I. B., Troyan, I. A., Fominskii, V. Yu.

المصدر: Glass and Ceramics ; volume 74, issue 11-12, page 434-439 ; ISSN 0361-7610 1573-8515

مصطلحات موضوعية: Materials Chemistry, Mechanics of Materials, Ceramics and Composites

الإتاحة: https://doi.org/10.1007/s10717-018-0011-zTest