Персона: Дубов, Леонид Юрьевич
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Инженерно-физический институт биомедицины
Цель ИФИБ и стратегия развития – это подготовка высококвалифицированных кадров на базе передовых исследований и разработок новых перспективных методов и материалов в области инженерно-физической биомедицины. Занятие лидерских позиций в биомедицинских технологиях XXI века и внедрение их в образовательный процесс, что отвечает решению практикоориентированной задачи мирового уровня – диагностике и терапии на клеточном уровне социально-значимых заболеваний человека.
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- ПубликацияТолько метаданныеIn situ study of atomic clustering in Fe-19 Ga type alloy(2024) Golovin, I. S.; Balagurov, A. M.; Pozdniakov, A. V.; Dubov, L. Y.; Дубов, Леонид Юрьевич
- ПубликацияОткрытый доступPALS and FTIR study of proton irradiated Si upon ageing(2019) Ilyukhina, O. V.; Funtikov, Y. V.; Khmelevsky, N. O.; Aksenenko, A. Y.; Dubov, L. Y.; Stepanov, S. V.; Shtotsky, Y. V.; Дубов, Леонид Юрьевич; Степанов, Сергей Всеволодович; Штоцкий, Юрий Владимирович© 2019 Author(s).Transformation of radiation defects structure in proton-irradiated silicon during 22 month ageing at room temperature were studied by means of the positron annihilation lifetime spectroscopy and Fourier transformed infrared spectroscopy. Three pairs of irradiated samples were isochronically annealed and measured after 1, 14 and 22 months since irradiation. Significant distinctions in behavior of the positron trapping rate upon annealing were detected. They can be explained by evolution of interstitial clusters in the disordered regions of irradiated Si during long-term ageing at room temperature.
- ПубликацияОткрытый доступPALS investigation of structural vacancies during phase transitions in Fe-27Ga and Fe-27Ga-0.1Tb alloys(2019) Golovin, I. S.; Palacheva, V. V.; Dubov, L. Y.; Shtotsky, Y. V.; Stepanov, S. V.; Akmalova, Y. A.; Дубов, Леонид Юрьевич; Штоцкий, Юрий Владимирович; Степанов, Сергей Всеволодович; Акмалова, Юлия Альфредовна© 2019 Author(s).Good mechanical properties and relatively low switching magnetic field make Fe-Ga alloys very useful magnetostrictive material for wide range of practical applications. Doping with rare-earth elements (such as Tb) can significantly increase magnetostriction, because Tb rearranges vacancy structure during phase transitions in Fe-27Ga alloys. It was found that A2 and D03 structures in Fe-27Ga have high density of Fe-monovacancies with the positron lifetime ≈180 ps regardless of the presence of Tb. Transition into L12 structure is accompanied by formation of a significant number of larger vacancy defects, which increases the e+ lifetime by 5 %. Addition of 0.2% Tb suppress formation of these large defects at annealing temperatures of 400-550°C. Presence of Tb also decreases concentration of vacancies in D019 structure. After annealing at 650°C D019 volume fraction in Fe-27Ga-0.2Tb decreases to 60 %, (according to the positron measurements) against 95 % in Fe-27Ga. In both alloys at 700°C number of monovacancies increases dramatically during formation of the bcc B2 phase.
- ПубликацияТолько метаданныеAnnealing of radiation-induced defects in tungsten: Positron annihilation spectroscopy study(2019) Terentyev, D.; Funtikov, Y. V.; Stolbunov, V. S.; Ogorodnikova, O. V.; Dubov, L. Y.; Stepanov, S. V.; Shtotsky, Y. V.; Efimov, V.; Gutorov, K.; Огородникова, Ольга Вячеславовна; Дубов, Леонид Юрьевич; Степанов, Сергей Всеволодович; Штоцкий, Юрий Владимирович; Ефимов, Виталий Сергеевич; Гуторов, Константин Михайлович© 2019 Elsevier B.V. Positron annihilation lifetime spectroscopy (PALS) was applied to study the annealing of radiation-induced defects in polycrystalline tungsten (W) irradiated with 21.6 MeV protons at 100 °C up to a fluence of 5 × 10 15 p/cm 2 . Three components were observed in the measured spectra: short-lifetime of 100–120 ps (positron annihilation in the defect-free W lattice), medium-lifetime of ∼190–330 ps (annihilation at mono-vacancies and small vacancy cluster containing ∼ 2–4 vacancies) and long-lifetime of ∼500 ps (annihilation in large vacancy clusters containing more than 10 vacancies). The irradiation of W with protons at 100 °C, primary, led to the formation of mono-vacancies, self-interstitial defects were created as well but migrated towards sinks during the irradiation. Onset of vacancy diffusion in W starts already at 200 °C before defect recovery stage III. After annealing at ∼400 °C, a sharp drop in the intensity of the positron medium-life component together with a simultaneous increase in positron lifetime from ∼220 to ∼280 ps is observed, and a long-life component appears. This indicates migration and annealing of vacancies and their agglomeration in large vacancy clusters. After annealing at 500–700C, the intensity of long-life component increases indicating the growth of large vacancy clusters but at 900 °C they anneal completely as the mean lifetime recovers nearly to the value measured in the un-irradiated material.