Sergey Sokovnin
Ural Federal University
Prof. Sergey Sokovnin got a degree of Doctor of Technical Sciences (in Electrophysics) in 2005. Since 2011 he is a leader of the Electrophysics Technology Group IEP UB RAS and professor of experimental physics department of the Ural Federal University. He created a method of nanopowder production by pulsed electron beam evaporation in low pressure gas. By this method, has produced the nanopowders with the characteristic size of 3-5 nm and the specific surface up to 338 m2/g for various applications in dosimetry, materials science and medicine.
By method of pulsed electron beam evaporation in vacuum [1] of targets from non-magnetic in bulk state, Al2O3, SiO2, CeO2 and YSZ (Y2O3-8% Gd2O3) oxides, magnetic nanopowders with a high specific surface were produced. The... [ view full abstract ]
By method of pulsed electron beam evaporation in vacuum [1] of targets from non-magnetic in bulk state, Al2O3, SiO2, CeO2 and YSZ (Y2O3-8% Gd2O3) oxides, magnetic nanopowders with a high specific surface were produced.
The nanopowders were irradiated in air in room-temperature by electrons with energy of 0.7 MeV with pulse FWHM of 100 ns, using a pulse-periodic accelerator URT-1 [2] for 15 and 30 minutes.
The magnetic, thermal, and cathodoluminescence characteristics of nanopowders were measured before and after irradiation. It was established that the electron irradiation non-monotonically changes the magnetization of the pristine samples. To the contrary, a clear correlation between the intensity of cathodoluminescence and theirradiationdoes is found in the most of the oxides. There was a decrease in the intensity of cathodoluminescence after irradiation.Thermal stability and phase transformations of unirradiated and irradiated CeO2 and YSZ oxides were analyzed by synchronous analysis using thermogravimetry and differential scanning calorimetry. Luminescent and thermal properties reflect the transformation of structural defects in NPs more strongly after the exposure to a pulsed electron beam in comparison with corresponding changes of the NP magnetic response.
Fig. 1 a) Dependences of the magnetization change in Al2O3 NP magnetic field up to 12 kOe from the irradiation time (left) and b) PCL spectra not (1) and irradiated samples with doses 31.5 MGy (2) and 63 MGy (3).
Fig. 2 a) Dependences of the magnetization change in YSZ NP magnetic field up to 12 kOe from the irradiation time (left) and b) PCL spectra of not (1) and irradiated samples with doses 31.5 MGy (2) and 63 MGy (3).
Reference
[1] Sokovnin S.Yu., Il'ves V.G.. Production of nanopowders using pulsed electron beam / Ferroelectrics, V.436 (2012), I.1, 101 - 107. DOI:10.1080/10584587.2012.730951
[2] Sokovnin S. Yu., Balezin M. E. and Shcherbinin S. V. A УPT-1M accelerator for radiation technologies. Instr. and Exp. Tech. V. 56 (2013), 4, 411-413. http://dx.doi.org/10.1134/S002...
