Study of Changes in Optical and Heat-Conducting Properties of AlN Ceramics under Irradiation with Kr15+ and Xe22+ Heavy Ions

Artem L Kozlovskiy; Maxim V Zdorovets; Vladimir V Uglov

doi:10.3390/nano10122375

Study of Changes in Optical and Heat-Conducting Properties of AlN Ceramics under Irradiation with Kr¹⁵⁺ and Xe²²⁺ Heavy Ions

Nanomaterials (Basel). 2020 Nov 28;10(12):2375. doi: 10.3390/nano10122375.

Authors

Artem L Kozlovskiy^{1

2}, Maxim V Zdorovets^{1

2

3}, Vladimir V Uglov⁴

Affiliations

¹ Engineering Profile Laboratory, L.N. Gumilyov Eurasian National University, Nur-Sultan 010008, Kazakhstan.
² Laboratory of Solid State Physics, The Institute of Nuclear Physics, Almaty 050032, Kazakhstan.
³ Department of Intelligent Information Technologies, Ural Federal University, 620075 Yekaterinburg, Russia.
⁴ Department of Solid State Physics, Belarus State University, 220030 Minsk, Belarus.

Abstract

AlN-based ceramics have great prospects for use in the field of structural materials for reactors of the new generation of GenIV, as well as dosimetric and optical devices. Interest in them is due to their unique physical and chemical properties, high resistance to degradation and excellent insulating properties. This work is devoted to the study of changes in the optical and heat-conducting properties of AlN ceramics as a result of irradiation with Kr¹⁵⁺ and Xe²²⁺ heavy ions with energies close to those of fission fragments of uranium nuclei, and fluences 10¹⁴-10¹⁵ ion/cm². During the study, dose relationships of changes in the optical properties of ceramics were established, as well as the effect of the type of ions on the degree of radiation damage and deterioration of optical characteristics. It has been found that an increase in the irradiation dose for Kr¹⁵⁺ ions leads to a slight increase in the depth of electron traps, while for samples irradiated with Xe²²⁺ ions there is a sharp increase in the depth of occurrence from 5 to 20%, depending on the irradiation dose. For samples irradiated with Xe²²⁺ ions, the greatest decrease in thermal conductivity was 19%, while for ceramics irradiated with Kr¹⁵⁺ ions, the maximum decrease was not more than 10%. The results show a significant resistance of ceramics to radiation damage by Kr¹⁵⁺ ions and negative effects, leading to a decrease in the resistance of optical and conductive properties of ceramics when irradiated with Xe²²⁺ ions with doses higher than 5 × 10¹⁴ ion/cm². Using the X-ray diffraction method, the dependences of structural distortions and changes in dislocation density in the structure of ceramics on the radiation dose were established. It has been determined that the main structural changes are associated with the fragmentation of grains, which result in an increase in the dislocation density, as well as deformation and distortion of the crystal lattice as a result of the formation of complex defects in the structure.

Keywords: aluminum nitride; defects; fission fragments; heavy ions; optical properties; radiation damage.