2019, Horodek, P., Kobets, A. G., Siemek, K., Skuratov, V. A., Скуратов, Владимир Алексеевич

© 2019 Polish Academy of Sciences. All rights reserved.Experimental studies of pure iron exposed to Xe26+ irradiation are reported. Implantations were made with the fluence of 5 × 1013 ions/cm2 using 167 MeV ions moderated to 122.5, 77.0, and 44.5 MeV. Investigations were performed with variable energy positron beam (VEP). Doppler broadening spectroscopy (DB) was applied. The analysis of obtained results gives information about the presence of various kind of open-volume defects. Two layers with different values of positron diffusion lengths were found in implanted samples. The deeper one was more defected.

2019, Cherkova, S. G., Volodin, V. A., Stoffel, M., Rinnert, H., Skuratov, V. A., Скуратов, Владимир Алексеевич

© 2018 Elsevier B.V. Germanium suboxide films and GeO/SiO2 multilayer heterostructures deposited onto Si(001) substrates using evaporation in high vacuum were modified using irradiation of 167 MeV Xe+26 ions with fluences varying from 1011 to 1013 cm−2. According to Raman spectroscopy data, the swift heavy ion irradiation does not lead to the expected decomposition of germanium suboxide in germanium nanoclusters and GeO2. Infrared absorption spectroscopy measurements show that under irradiation the GeO/SiO2 layers were intermixed with formation of Ge-O-Si bonds. We report strong photoluminescence in the visible range at room temperature, which is most probably due to Ge-related defect-induced radiative transitions. Moreover, a new infrared luminescence band (~0.8 eV) was observed in irradiated structures, which can be related to defects or defects complexes in GexSiyO2 glass.

2019, Cherkova, S. G., Volodin, V. A., Skuratov, V. A., Скуратов, Владимир Алексеевич

© 2019, Pleiades Publishing, Ltd.Abstract: The optical properties of float-zone (FZ) silicon irradiated with swift heavy ions (SHI) are studied. In the low-temperature photoluminescence spectra, a broad peak in the range 1.3–1.5 μm is evident along with the well-known X, W, W', R, and C lines. In this case, it is found that, as the irradiation dose is increased in the range 3 × 1011–1013 cm–2, the photoluminescence peak falls and narrows and, at the same time, its maximum shifts to longer wavelengths.

2019, Khmelnitski, R. A., Kononenko, V. V., O'Connell, J. H., Syrykh, G. F., Skuratov, V. A., Скуратов, Владимир Алексеевич

© 2018 Elsevier B.V. Diamond preliminary damaged with neutrons was irradiated with swift heavy ions (SHI, 1030 MeV 209Bi) decelerated in the electronic stopping regime as well as with fs-laser pulses. The initial excess electronic energy densities appearing in the nanometric vicinity of the SHI trajectories and within the absorbing layers in laser spots were comparable (∼1024 eV cm−3). Graphitization of diamond in the central parts of the lased spots was observed above the threshold fluence of 15–30 J/cm−2. It was also found that the lower threshold fluence is required for initiating graphitization as well as destruction of the pre-damaged crystal by laser pulses in comparison to that for undamaged diamond. This indicates a noticeable effect of an existing defect ensemble on the kinetics of diamond transformations in laser spots. However, X-ray diffraction, atomic-force microscopy, and electron microscopy detected no graphitic domains within the SHI-irradiated pre-damaged crystal. The research demonstrated that the density of the initial excess electronic energy cannot be treated as the sole parameter governing subsequent structure transformations in diamond. Large differences between the spatial as well as temporal scales finally results in different pathways of the relaxation kinetics of this excess energy in laser spots and SHI tracks in diamond.

2023, Rymzhanov, R. A., O’Connell, J. H., Medvedev, N., Ćosić, M., Skuratov, V. A., Janse van Vuuren, A., Volkov, A. E., Скуратов, Владимир Алексеевич

Swift heavy ions (SHI) penetrating through a solid lose main part of the energy to the electronic stopping. The extremely high level of the electronic excitation generated by incoming ion at the femtosecond scale is followed by relaxation of the perturbed electron ensemble. Subsequently, the acceleration of target atoms occurs at sub-picosecond times, resulting in the formation of a nanometric damaged region within hundreds of picoseconds after the ion passage. These structural changes can affect its physical, chemical, and mechanical properties of the irradiated target. Due to these features, accelerated ion beams serve as a versatile tool for the patterning and modification of nanometric materials [1,2], as well as the investigation of radiation stability against cosmic rays and fission fragments.

2019, Karganov, M. Y., Alchinova, I. B., Polyakova, M. V., Feldman, V. I., Skuratov, V. A., Скуратов, Владимир Алексеевич

© 2019Effects of irradiations of Phage Lambda dry DNA samples at room and cryogenic temperatures with 158 MeV Xe and 48 MeV Ar ions were investigated. These ions primary transfer energy into the electronic subsystem of a target: dE/dx = Se, Se Xe = 10.8 keV/nm and Se Ar = 3.5 keV/nm. Site-specific enzymes restriction endonucleases were applied to indicate DNA damages induced by these ions. Electrophoresis was applied to analyze the dependencies of the distributions of DNA fragments sizes on the ion fluence ranging from 108 cm−2 to 1010 cm−2. Electron paramagnetic resonance (EPR)technique was used to investigate damages of a dry DNA sample irradiated at the cryogenic temperature (140 K)with 158 MeV 132 54Xe26+ ions up to the fluence 8.6·109cm−2. A poorly resolved signal centered at the g-factor value for the free electron g ≈ ge was detected, which probably results from a mixture of different-type radicals trapped in the DNA film. The total concentration of paramagnetic species in this sample was estimated to be 1.3 × 1019 spin/g.

2019, Janse, van, Vuuren, A., O'Connell, J. H., Aralbayeva, G., Dauletbekova, A., Saifulin, M. M., Skuratov, V. A., Скуратов, Владимир Алексеевич

© 2018 Elsevier B.V. Transmission electron microscopy techniques were used to analyse the effect of swift heavy ion irradiation on both yttrium aluminium perovskite (YAP) YAlO3, and yttrium aluminium garnet (YAG) Y3Al5O12 single crystals. The crystals were irradiated with Kr, Xe and Bi ions with energies ranging from 107 to 1030 MeV. These ions have electronic stopping powers in the range from 11 to 41 keV/nm. The ion fluences were all within the non-overlapping regime for latent ion tracks i.e. 1011–1012 cm−2. A number of crystals were also irradiated at different temperatures of 80, 300 and 1000 K at a fixed stopping power. Latent ion tracks with an amorphous core were observed in all samples. The track diameters were seen to increase with increasing stopping power. Track diameters only increase by a significant amount as a result of irradiation temperature at 1000 K, whereas the diameters at 80 and 300 K differ only slightly. Ion tracks in YAG were also found to be larger than those in YAP at comparable stopping powers. It was found that on average 10 keV/nm of extra energy input is required to produce ion tracks in YAP with diameters similar to those in YAG. The results also suggest that the complexity of the crystal structure plays a significant role in the formation of ion tracks in these crystals.

2021, Korneeva, Е. А., Ibrayeva, A., O’Connell, J., Mutali, A., Sohatsky, A. S., Vershinina, T. N., Skuratov, V. A., Zdorovets, М., Alekseeva, L. S., Nokhrin, A. V., Скуратов, Владимир Алексеевич

In recent years, nuclear industry development must be response to new requirements of safety, sustainability and effectiveness. The operating conditions of nuclear reactors of new design would tend to more damage operation mode, in particular, high temperature and high dozes. Oxide dispersion strengthened (ODS) alloys now have been widely investigated as perspective constructive materials for fuel claddings in Generation IV nuclear reactors due to their high values of high temperature creep resistance and resistance to irradiation swelling [1- 3]. High operation properties of ODS alloys are due to nanosized dielectric particles based mainly on yttrium oxides embedded in the metallic matrix. These thermostable nanosized particles are responsible for resistance to dislocation motion that regulate high-temperature creep resistance and tensile properties at high temperatures as well as provide swelling resistance while acting as sinks for radiation defects. Nowadays most literature data are devoted to study structure stability of ODS alloys under neutron and low-energy ion irradiation that didn’t show any significant effect on the ODS structure [4,5]. At the same time apart from neutron irradiation cladding materials in reactor core will contact with fission fragments (FF) that can dramatically affect the structure of dielectric materials even down to complete amorphization due to high levels of electronic excitation [6]. Therefore, studying the structure behavior of oxide nanoparticles in metallic matrix under FF impact can broaden the idea of operational limits and conditions of ODS steels for new reactors. The aim of present study is the complex investigation of radiation stability of nanostructured Y-Ti-O and Y-Al-O compounds embedded in metallic matrix and as separate oxides at a broad range of electronic stopping power and ion fluences.

2017, Privezentsev, V. V., Skuratov, V. A., Kulikauskas, V. S., Makunin, A. V., Ksenich, S. V., Steinman, E. A., Tereshchenko, A. N., Скуратов, Владимир Алексеевич

The properties of metal nanoparticles (NPs) are comprehensively investigated because of its possible application in modern opto/microelectronic devices. Metal zinc NPs can be use in UV photo-detectors based on surface plasmon resonance phenomena [1]. There are a number of publications attempted to the formation of metal NPs by supersaturation of silicon with these metals. Among them there are works connected with formation of Zn NPs in Si ion implantation [2-4]. In recent years, there were much attention has been paid to the problems of creating combined microelectronics and photonics systems on silicon substrate. So silicon is non-direct semiconductor, it is not a convenient material for these purposes. The important task is the search for ways to synthesize NPs with a narrow size distribution. Swift heavy ion irradiation (SHI) beams allows selectivity to control the dimensions of formed NPs [5]. As known SHI irradiation lead to formation of so-called latent tracks (nanometer-sized disordered regions around ion trajectory) in many oxide crystals and corresponding track-associated radiation damage may induce the change of NP form from spherical to ellipsoidal. This effect is most noticeable for multiple (about 100 times) SHI impacts [6]. In this work the Zn nanoparticles were synthesized in Si by high-dose and low-energy Zn ion implantation. Then there was carried out the modification of implanted samples by high-energy Xe ion irradiation.

2019, O'Connell, J. H., Janse, van, Vuuren, A., Kirilkin, N. S., Zdorovets, M. V., Saifulin, M. M., Skuratov, V. A., Скуратов, Владимир Алексеевич

© 2018 Elsevier B.V. Bulk yttrium-iron garnet (YIG) single crystals have been irradiated with swift Kr and Xe ions having energies from 0.4 to 22.8 MeV/u and electronic stopping powers from 8.9 to 28.9 keV/nm near the irradiated surface. Transmission electron microscopy (TEM) has been used for direct observation of non-overlapping amorphous latent tracks in the near surface region of the irradiated bulk YIG crystals. The amorphous track radii observed in this work have been compared with previously reported data from direct and indirect measurements. It was found that the thickness of the sample subjected to swift heavy ion irradiation does not significantly affect the resulting amorphous track size observed by TEM in YIG. The results also support previously observed consistency between direct TEM and indirect Rutherford backscattering in channelling mode (RBS/C) and Mossbauer spectroscopy (MS) methods for amorphous track evaluation in YIG when electronic stopping power is greater than ∼13 keV/nm, which is sufficient to create cylindrical amorphous tracks by high velocity ions (E > 10 MeV/u). Indirect methods provide underestimated values compared to TEM when the electronic stopping power is below ∼13 keV/nm, for which discrete amorphous tracks are supposed to be formed by high velocity ions.