Персона: Скуратов, Владимир Алексеевич
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Институт ядерной физики и технологий
Цель ИЯФиТ и стратегия развития - создание и развитие научно-образовательного центра мирового уровня в области ядерной физики и технологий, радиационного материаловедения, физики элементарных частиц, астрофизики и космофизики.
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Владимир Алексеевич
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- ПубликацияОткрытый доступIrradiation effects of swift heavy ions on palladium films deposited on 6H-SiC substrate(2019) Thabethe, T. T.; Nstoane, T.; Biira, S.; Njoroge, E. G.; Skuratov, V. A.; Скуратов, Владимир Алексеевич© 2019 Elsevier B.V. The irradiation effect of swift heavy ions on palladium (Pd) films deposited on 6H-SiC was investigated. The samples were irradiated by Xe26+ ions with the energy of 167 MeV at fluences of 1 × 1013 cm−2 and 3 × 1014 cm−2 at room temperature. Phase identification, residual stress and surface morphology were investigated with X-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD results showed that the as-deposited sample was composed of Pd and SiC with no evidence of a reaction between Pd and SiC. No reaction was observed for the lower irradiation fluence, only an increase in the Pd peak intensities was observed indicating improvement in the crystallinity of the material. A reaction between Pd and SiC forming PdSi and Pd2Si was observed after irradiation at a fluence of 3 × 1014 cm−2. The stress measurements indicated that the films were having tensile and biaxial stress not exceeding 200 MPa. A decrease in stress values was observed with an increase in irradiation fluence. The surface morphology of the as-deposited was flat and composed of small granules. There was an increase in granule sizes due to irradiation at 1 × 1013 cm−2. Irradiating at 3 × 1014 cm−2 caused grain agglomeration and clustering.
- ПубликацияОткрытый доступInfrared spectroscopy of ion tracks in amorphous SiO2 and comparison to gamma irradiation induced changes(2019) Karlusic, M.; Skrabic, M.; Majer, M.; Buljan, M.; Skuratov, V. A.; Скуратов, Владимир Алексеевич© 2018 Elsevier B.V. Ion track formation in amorphous SiO2 was investigated using infrared spectroscopy. For comparison, one set of samples was also irradiated using 1.25 MeV gamma rays. An increase of 1044 cm−1 peak and decrease of 1078 cm−1 peak was observed in all cases. Experimental results were analysed using an analytical thermal spike model and non-standard model parameters were found. This finding is attributed to the amorphous structure of the material.
- ПубликацияОткрытый доступEnergy dependent structure of Xe ion tracks in YBCO and the effect on the superconductive properties in magnetic fields(2019) Suvorova, E. I.; Degtyarenko, P. N.; Karateev, I. A.; Ovcharov, A. V.; Skuratov, V. A.; Скуратов, Владимир Алексеевич© 2019 Author(s).The morphology and structure of damaged regions (tracks) produced by swift heavy 167, 77, and 46 MeV 132Xe23+ ions in YBCO-based second generation industrial high temperature superconductors wires (2G HTS) were studied using transmission electron microscopy. It was shown that ions produce tracks aligned along the ion trajectory but of morphology depending on their energy: continuous, nearly continuous, or discontinuous tracks like prolate ellipsoids of 10-15 nm in length and spheroids of 5 nm in diameter. The damaged regions of about 5 nm in diameter contain an amorphous material with a lower density compared to the pristine YBCO. The material density drops from 6300 kg m-3 for YBCO matrix to 3600 kg m-3 inside the tracks. Barium enrichment was found in the vicinity of the track at a distance of about 10 nm from the center of the defect. Ion damage tracks with different morphologies showed different effectivenesses as pinning centers. Tracks composed of discontinuous pinning centers - spheroids of about 5 nm in diameter - bring the best enhancement of the critical current density. It occurs for the lowest ion energy (46 MeV) in the range of energy loss of 8.9 keV/nm-4.7 keV/nm for Xe ions. The samples showed highest critical current densities of 56 MA/cm2 (4.2 K) and 3 MA/cm2 (77 K) in self-field, while in magnetic fields of 8 T, the values of 17 MA/cm2 (4.2 K) and 1.6 MA/cm2 (77 K) were achieved. The reduction of the superconducting volume corresponding to the amorphous radiation defects did not exceed 4% from the total sample volume.
- ПубликацияОткрытый доступSlow and swift heavy ions irradiation of zirconium nitride (ZrN) and the migration behaviour of implanted Eu(2019) Mokgadi, T. F.; Madito, M. J.; Mlambo, M.; Motloung, S. V.; Skuratov, V. A.; Скуратов, Владимир Алексеевич© 2019 Elsevier B.V.Zirconium nitrate (ZrN) layers of about 20 µm were deposited onto silicon (Si) substrates at room temperature (RT) using a vacuum arc deposition technique. Some of the as-deposited samples were irradiated with Eu (360 keV) to a fluence of 1.0 × 1016 cm−2 at RT. Others were irradiated with 167 MeV Xe ions to the fluence of 6.7 × 1014 cm−2 at RT. Both Eu and Xe irradiated samples were annealed at 800 and 900 °C for 5 h. The as-deposited samples were characterised by X-ray diffraction (XRD) and Raman spectroscopy while irradiated and annealed samples were characterised by Raman spectroscopy and Rutherford backscattering spectrometry (RBS). XRD results showed (1 1 1), (2 0 0), (3 1 1) and (2 2 2) planes of ZrN confirming the polycrystalline nature as-deposited layers Raman results of as-deposited ZrN showed all vibration modes indicating ZrN with defects. Irradiation with slow ions resulted in the accumulation of defects in the irradiated samples. Fewer defects were observed in the swift heavy ions irradiated samples. Thermal annealing at 800 and 900 °C resulted in different stoichiometric structures of ZrN with broken octahedral symmetry. No migration of implanted Eu was observed after annealing at these temperatures.
- ПубликацияОткрытый доступEffect of swift heavy ions irradiation on the migration behavior of strontium implanted into polycrystalline SiC(2019) Abdelbagi, H. A. A.; Motloung, S. V.; Njoroge, E. G.; Mlambo, M.; Skuratov, V. A.; Скуратов, Владимир Алексеевич© 2019 Elsevier B.V. The influence of swift heavy ions (SHIs) irradiation on the microstructure and the migration behavior of strontium (Sr) implanted into polycrystalline SiC were investigated using Rutherford backscattering spectrometry (RBS), Raman spectroscopy and scanning electron microscopy (SEM). The as-implanted and SHIs irradiated samples were vacuum annealed from 1100 to 1500 °C in steps of 100 °C for 5 h. Implantation of strontium (Sr) amorphized the SiC, while SHIs irradiation of the as-implanted SiC resulted in limited recrystallization of the initially amorphized SiC. Annealing at 1100 °C already caused recrystallization in both the irradiated and un-irradiated but implanted with Sr samples. At 1500 °C, a carbon layer appeared on the surface of the irradiated and un-irradiated but implanted with Sr samples. This was due to the decomposition of the SiC and subsequent sublimation of silicon leaving a free carbon layer on the surface. SHIs irradiation alone induced no change in the implanted Sr. Annealing the samples at 1400 °C caused a release of all implanted strontium in the SHIs irradiated samples, while 55% of implanted strontium was released in the un-irradiated but implanted with Sr samples. The enhanced Sr releasing in SHIs irradiated samples was explained in terms of the high number of pores in the irradiated samples compared to fewer pores in the un-irradiated but implanted with Sr samples. The results show that more Sr was released in the irradiated SiC samples.
- ПубликацияОткрытый доступCharacterization of 167 MeV Xe ion irradiated n-type 4H-SiC(2019) Madito, M. J.; Hlatshwayo, T. T.; Mtshali, C. B.; Manyala, N.; Skuratov, V. A.; Скуратов, Владимир Алексеевич© 2019 Elsevier B.V.The nitrogen-doped, n-type 4H-SiC with 6 μm thick epitaxial layer was irradiated at the perpendicular incidence and room temperature by 167 MeV Xe+26 ions to a fluence of 5 × 1012 cm− 2. The Monte Carlo simulation code, Stopping and Range of Ions in Matter (SRIM) was used to simulate the Xe26+ ions irradiated in SiC. The Rutherford backscattering spectrometry (RBS) analysis with 3.5 MeV He++ ions which have a projected range of ~9 μm in SiC (SRIM prediction) did not detect implanted Xe. Raman spectroscopy and imaging depth profiles clearly showed three distinct parts of the swift heavy ion (SHI)-irradiated 4H-SiC, i.e. 5.6 μm irradiated epitaxial layer, 6.9 μm damaged irradiated layer and non-irradiated 4H-SiC bulk. Raman spectroscopy showed new broad bands of crystalline Si[sbnd]Si and distorted Si[sbnd]C in the damaged irradiated layer. The new Si[sbnd]Si bands were attributed to the ordering in the Si[sbnd]Si homonuclear bonds without crystal amorphization. The scanning near-field optical microscopy (SNOM) results of the SHI-irradiated 4H-SiC sample displayed a very low signal counts (transmission) compared to the virgin sample, and this difference in the optical absorption could be correlated with the defects energy levels created within the bandgap of the sample upon irradiation.
- ПубликацияОткрытый доступInvestigating the structural changes induced by SHI on W–SiC samples(2020) Thabethe, T. T.; Ntsoane, T. P.; Biira, S.; Njoroge, E. G.; Skuratov, V. A.; Скуратов, Владимир Алексеевич© 2020 Elsevier LtdThe structural modification of tungsten-SiC samples irradiated with Xe26+ swift heavy ions (SHIs) was investigated. Tungsten (W) thin films were deposited on 6H–SiC using e-beam. After deposition, the W–SiC samples were irradiated by 167 MeV Xe26+ ions to fluences of 1012 cm−2, 1013 cm−2 and 1014 cm−2 at room temperature. The sample composition, phase identification, residual stress component and surface morphology were investigated with Rutherford backscattering spectrometry (RBS), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results indicated that the as-deposited samples were composed of W and SiC, with no reaction between them. The samples irradiated to a fluence of 1012 cm−2 showed that a reaction between W and SiC took place resulting in the formation of WSi2 and WC phases. The samples irradiated to fluences of 1013 and 1014 cm−2 showed further reactions between W and SiC with WSi2 and WC being the only phases formed. The SiC substrate had bi-axial compressive stress which did not excess 700 MPa after irradiating to the highest fluence. The W layer deposited on SiC was flat and homogeneous after deposition. A textured surface with identifiable grains was observed after the SHI irradiations.
- ПубликацияОткрытый доступMD and TEM evaluation of swift Xe ion induced latent tracks in Si3N4(2019) Rymzhanov, R. A.; Zhalmagambetova, A.; Ibrayeva, A.; Janse, van, Vuuren, A.; Skuratov, V. A.; Скуратов, Владимир Алексеевич© 2019As known silicon nitride ceramics is considered as a candidate material for inert matrix fuel hosts used for transmutation of minor actinides. Unfortunately, by now very limited data is devoted to investigate of its stability under high energy heavy ion irradiation simulating fission fragment impact. Aim of our present study is a comparative analysis of parameters of latent tracks induced with swift Xe ion irradiation in polycrystalline Si 3 N 4 using molecular dynamic (MD) simulation and high resolution transmission electron microscopy (TEM). Silicon nitride samples were irradiated with 220 MeV xenon ions at room temperature to fluence 5 × 10 11 cm −2 that correspond to ion track non overlapping regime and allows to analyze single ion track regions. The calculated MD and experimental TEM values of track diameter for 220 MeV Xe irradiation are found to be in a good agreement and equal about 2 nm, whereas the threshold ionizing energy loss for track formation predicted by MD is lower than threshold value from TEM measurements (11.5 keV/nm vs 15 keV/nm). The averaging of all presented data gives the threshold energy loss level ∼ 13 ± 2 keV/nm.
- ПубликацияОткрытый доступRaman scattering in diamond irradiated with high-energy xenon ions(2020) Kazuchits, N. M.; Korolik, O. V.; Rusetsky, M. S.; Kazuchits, V. N.; Skuratov, V. A.; Скуратов, Владимир Алексеевич© 2020 Elsevier B.V.Accumulation of radiation damage and associated mechanical stresses in diamonds irradiated with 167 MeV Xe ions to fluences 1.0 × 1010 ÷ 8.15 × 1014 cm−2 have been studied using confocal Raman spectroscopy. The spectra were measured in a backscattering geometry across the irradiated layer by scanning the edge of single crystalline synthetic samples with nitrogen concentration 3 ÷ 5 ppm. All spectra were recorded at room temperature. Parameters of the 1332 cm−1 first-order Raman line – the FWHM and peak position, studied as function of Xe ion fluence, were used to characterize the structural disorder and mechanical stress level.
- ПубликацияОткрытый доступChange in Superparamagnetic State Induced by Swift Heavy Ion Irradiation in Nano-Maghemite(2024) Stichleutner, S.; Herczeg, B.; Pechoušek, J.; Libor M.; Skuratov, V. A.; Скуратов, Владимир АлексеевичThe effect of swift heavy ion irradiation on solў??gel-prepared maghemite nanoparticles was studied by 57Fe transmission Mѓ?ssbauer spectroscopy and X-ray diffractometry (XRD). The room temperature Mѓ?ssbauer spectra of the non-irradiated nano-maghemite showed poorly resolved magnetically split, typical relaxation spectra due to the superparamagnetic state of the nanoparticles. Significant changes in the line shape, indicating changes in the superparamagnetic state, were found in the Mѓ?ssbauer spectra upon irradiation by 160 MeV and 155 MeV 132Xe26+ ions with fluences of 5 ѓ? 1013 ion cmў??2 and 1 ѓ? 1014 ion cmў??2. XRD of the irradiated maghemite nanoparticles showed a significant broadening of the corresponding lines, indicating a decrease in the crystallite size, compared to those of the non-irradiated ones. The results are discussed in terms of the defects induced by irradiation and the corresponding changes related to the change in particle size and consequently in the superparamagnetic state caused by irradiation.
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