Study of Changes in Optical and Heat-Conducting Properties of AlN Ceramics under Irradiation with Kr(15+) and Xe(22+) Heavy Ions

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 Kr(15+) and Xe(22+) heavy ions with energies close to those of fission fragments of uranium nuclei, and fluences 10(14)–10(15) ion/cm(2). 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 Kr(15+) ions leads to a slight increase in the depth of electron traps, while for samples irradiated with Xe(22+) ions there is a sharp increase in the depth of occurrence from 5 to 20%, depending on the irradiation dose. For samples irradiated with Xe(22+) ions, the greatest decrease in thermal conductivity was 19%, while for ceramics irradiated with Kr(15+) ions, the maximum decrease was not more than 10%. The results show a significant resistance of ceramics to radiation damage by Kr(15+) ions and negative effects, leading to a decrease in the resistance of optical and conductive properties of ceramics when irradiated with Xe(22+) ions with doses higher than 5 × 10(14) ion/cm(2). 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.