Radiation-induced degradation effects of optical properties of MgO ceramics caused by heavy ion irradiation

The paper presents the results of a study of the connection between structural changes caused by irradiation with heavy Xe²²⁺ ions in MgO ceramics, which are characteristic of the damage accumulation caused by exposure to nuclear fuel fission fragments. Interest in this type of ceramics, as one of the promising classes of dielectrics, is due to the potential for using them as materials for creating a matrix that holds fissile nuclear fuel, and in the case of consideration of these ceramics as dopants used to enhance the resistance of inert matrices to destruction caused by irradiation. The obtained assessment results of the alterations in the transmittance coefficient for irradiated ceramics contingent upon the irradiation fluence indicate the transmittance degradation of irradiated ceramics in the UV range, caused by the accumulation of structural distortions caused by irradiation, alongside a growth in the concentration of absorbing centers and oxygen vacancies. It has been established that the dominant type of defects in the damaged layer are oxygen vacancies, the accumulation of which occurs due to deformation distortions and the rupture of chemical bonds. At the same time, the observed change in the crystal structure volume is due to the formation of complex defects of the Mg + V_O type, the formation of which results in deformation broadening of the crystal lattice parameters.