Персона: Чернышева, Ольга Викторовна
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Институт лазерных и плазменных технологий
Стратегическая цель Института ЛаПлаз – стать ведущей научной школой и ядром развития инноваций по лазерным, плазменным, радиационным и ускорительным технологиям, с уникальными образовательными программами, востребованными на российском и мировом рынке образовательных услуг.
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Ольга Викторовна
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- ПубликацияТолько метаданныеMagnetization of Crystalline and Amorphous Phases of R(2)Ti(2)O(7)and R2Zr2O7(R = Gd, Dy, Tb)(2020) Kuznetsov, A. V.; Churkin, O. A.; Popov, V. V.; Shchetinin, I. V.; Ivanov, A. A.; Yaroslavtsev, A. A.; Gaynanov, B. R.; Yastrebtsev, A. A.; Chernysheva, O. V.; Alekseev, P. A.; Menushenkov, A. P.; Кузнецов, Алексей Владимирович; Чуркин, Олег Алексеевич; Попов, Виктор Владимирович; Иванов, Андрей Анатольевич; Гайнанов, Булат Радикович; Ястребцев, Алексей Алексеевич; Чернышева, Ольга Викторовна; Алексеев, Павел Александрович; Менушенков, Алексей ПавловичWe present the study of frustrated magnets R2M2O7, where R = Gd, Dy, Tb and M = Ti, Zr. Magnetic susceptibility chi and low-temperature magnetization of perfectly ordered pyrochlores R2Ti2O7, partially disordered fluorites R2Zr2O7, and their completely disordered amorphous phases were measured and analyzed. We have found that structural disorder weakens the exchange interaction of the rare-earth ions. Magnetic moments of dysprosium and terbium, obtained from nearly saturated magnetization, are slightly affected by the disorder while the gadolinium moment is completely independent of it. The local structure of the compounds, including oxygen environment of the rare-earth ions, is discussed in terms of the influence of the crystal electric field on the magnetic properties of R2M2O7.
- ПубликацияТолько метаданныеThe effect of changes in the local atomic structure on the magnetic properties of amorphous iron-based alloys deformed by high-pressure torsion at different temperatures(2019) Sundeev, R. V.; Shalimova, A. V.; Veligzhanin, A. A.; Glezer, A. M.; Chernysheva, O. V.; Чернышева, Ольга Викторовна© 2019 Elsevier B.V. The changes of local atomic structure of amorphous magnetically soft iron-based Fe 50 Ni 33 B 17 , Fe 54 Ni 29 B 17 , Fe 58 Ni 25 B 17 , and Fe 75 Si 8 B 17 alloys have been studied upon high-pressure torsion (HPT)at 77 K and 293 K. The set of structure research methods used for the study included EXAFS spectroscopy in synchrotron radiation, X-ray diffraction, transmission electron microscopy, and differential scanning calorimetry. The effect of HPT regimes on the character of the local atomic environment of iron and nickel atoms has been established. The magnetic properties of the alloys were measured with a vibration magnetometer at room temperature. The correlation between the specific saturation magnetization and the parameters of the local atomic structure has been revealed. It is shown that the amorphous state after HPT is characterized by a significant change in the saturation magnetization and coercive force relative to those of the initial state.
- ПубликацияТолько метаданныеLocal atomic and crystal structure of rapidly quenched TiNiCu shape memory alloys with high copper content(2021) Veligzhanin, A.; Sundeev, R.; Chernysheva, O.; Shelyakov, A.; Sitnikov, N.; Borodako, K.; Чернышева, Ольга Викторовна; Шеляков, Александр Васильевич; Ситников, Николай Николаевич; Бородако, Кирилл Анатольевич© 2020 Elsevier B.V.This study aims to reveal features of the local crystal structure and environment in the quasi-binary TiNi–TiCu alloys containing 25–40 at.% Cu, by X-ray diffraction and EXAFS spectroscopy. The alloys were produced in an amorphous state by the melt-spinning technique and then crystallised by isothermal and electropulsing treatment. It was shown that Ni local structure is more disordered in comparison with Cu local environment, which is closer to the conventional crystallographic structure. An increase in the Cu content resulted in the magnification of the disordering in the nearest local environment, around both the Ni and Cu atoms, consisting of Ti atoms. No noticeable effect of the annealing rate on the local structure was found.
- ПубликацияТолько метаданныеEXAFS-spectroscopy and thermal neutron diffraction study of the effect of deformation by high pressure torsion on the atomic ordering and magnetic properties of the FeCo alloy(2021) Glezer, A. M.; Muradimova, L. F.; Borisova, P. A.; Veligzhanin, A. A.; Chernysheva, O. V.; Чернышева, Ольга Викторовна© 2021 Elsevier B.V.The specific features of B2 atomic ordering and the ordering-dependent structure and magnetic characteristics of the FeCo alloy upon quasi-hydrostatic high-pressure torsion (HPT) in the Bridgman anvils at room and elevated temperatures and subsequent annealing have been studied by thermal neutron diffraction, X-ray diffraction, EXAFS spectroscopy, and magnetometry. An abrupt decrease in the degree of long-range order upon HPT has been revealed by neutron diffraction and EXAFS spectroscopy data exhibiting the formation of an almost ideal B2 ordering of in the nearest coordination spheres of Fe and Co atoms.
- ПубликацияТолько метаданныеThe influence of BaSnO3and BaZrO3nanoinclusions on the critical current and local structure of HTS coated conductors(2022) Kaul, A. R.; Chepikov, V. N.; Mathon, O.; Monteseguro, V.; Menushenkov, A. P.; Ivanov, A. A.; Chernysheva, O. V.; Rudnev, I. A.; Osipov, M. A.; Менушенков, Алексей Павлович; Иванов, Андрей Анатольевич; Чернышева, Ольга Викторовна; Руднев, Игорь Анатольевич; Осипов, Максим Андреевич© 2022 IOP Publishing Ltd.We studied the effect of artificial pinning centers in the form of nanoinclusions of stannate BaSnO3 (BSO) and zirconate BaZrO3 (BZO) barium on the critical current of high-temperature superconducting tapes of the second generation (2G) based on YBa2Cu3O 7-δ films (YBCO). It has been found that the introduction of BaZrO3 nanoinclusions increases the critical current at 77 K for the magnetic field direction parallel and normal to the tape surface, while the introduction of BaSnO3 nanoinclusions decreases the critical current in both cases. To elucidate the origin of a different impact of nanoinclusions we examined the local structure of the YBCO-matrix using x-ray absorption spectroscopy (EXAFS and XANES). The spectra were collected at K-edges of Cu, Sn, and Zr at the European Synchrotron (ESRF). It was revealed that the introduction of BaZrO3 nanoinclusions increases the stiffness of copper-oxygen bonds in superconducting CuO2 plane and minimizes their static disorder in the YBCO matrix, while the introduction of BaSnO3 nanoinclusions leads to a significant increase in static disorder with a relatively weak effect on the stiffness of Cu-O bonds. These changes in the local structure become decisive for changing the macroscopic properties of high-temperature superconductor-tapes.
- ПубликацияОткрытый доступКорреляция локальных и макроскопических свойств сплавов на основе переходных металлов: TiNiCu, CeFeMn, FeNiAl(НИЯУ МИФИ, 2016) Чернышева (Гришина), О. В.; Чернышева, Ольга Викторовна; Менушенков, А. П.
- ПубликацияТолько метаданныеInfluence of Amorphous State Local Structure in Tinicu Alloys on Structure and Phase Transformations during Crystallization(2023) Borodako, K.; Chernysheva, O.; Shelyakov, A.; Koledov, V.; Чернышева, Ольга Викторовна; Шеляков, Александр Васильевич
- ПубликацияТолько метаданныеInfluence of Crystallization Conditions on Local Atomic Structure of Austenite in Rapidly Quenched Tinicu Shape Memory Alloys(2023) Shelyakov, A.; Chernysheva, O.; Borodako, K.; Sitnikov, N.; Seregin, A.; Шеляков, Александр Васильевич; Чернышева, Ольга Викторовна; Бородако, Кирилл Анатольевич; Ситников, Николай Николаевич; Серегин, Алексей Александрович
- ПубликацияОткрытый доступInfluence of Synthesis Conditions on the Crystal, Local Atomic, Electronic Structure, and Catalytic Properties of (Pr1−xYbx)2Zr2O7 (0 ≤ x ≤ 1) Powders(2023) Popov, V. V.; Menushenkov, A. P.; Yastrebtsev, A. A.; Gaynanov, B. R.; Chernysheva, O. V.; Ivanov, A. A.; Rudakov, S. G.; Berdnikova, M. M.; Pisarev, A. A.; Попов, Виктор Владимирович; Менушенков, Алексей Павлович; Ястребцев, Алексей Алексеевич; Гайнанов, Булат Радикович; Чернышева, Ольга Викторовна; Иванов, Андрей Анатольевич; Рудаков, Сергей Геннадьевич; Бердникова, Мария Михайловна; Писарев, Александр АлександровичThe influence of Yb3+ cations substitution for Pr3+ on the structure and catalytic activity of (Pr1в€’xYbx)2Zr2O7 powders synthesized via coprecipitation followed by calcination is studied using a combination of long- (s-XRD), medium- (Raman, FT-IR, and SEM-EDS) and short-range (XAFS) sensitive methods, as well as adsorption and catalytic techniques. It is established that chemical composition and calcination temperature are the two major factors that govern the phase composition, crystallographic, and local-structure parameters of these polycrystalline materials. The crystallographic and local-structure parameters of (Pr1в€’xYbx)2Zr2O7 samples prepared at 1400 В°C/3 h demonstrate a tight correlation with their catalytic activity towards propane cracking. The progressive replacement of Pr3+ with Yb3+ cations gives rise to an increase in the catalytic activity. A mechanism of the catalytic cracking of propane is proposed, which considers the geometrical match between the metal–oxygen (Pr–O, Yb–O, and Zr–O) bond lengths within the active sites and the size of adsorbed propane molecule to be the decisive factor governing the reaction route.