The influence of variation in the ratio of components in two-phase lithium-containing ceramics on defect formation processes

• Variation of ceramic composition leads to increased radiation resistance. • The kinetics of accumulation of radiolysis products under neutron irradiation. • The relationship between defects and degradation of strength and thermal parameters. • The effect of neutron irradiation on the kinetics of radiation damage accumulation. The aim of this study is to determine the effect of changing the ratio of components in the composition of two-component xLi 2 TiO 3 − (1-x)Li 2 ZrO 3 ceramics on structural distortions and degradation of strength and thermal parameters under high-dose neutron irradiation. The assessment of structural changes was carried out using the electron paramagnetic resonance (EPR) method, which is one of the most accurate methods that allows for a quantitative and qualitative assessment of structural changes caused by irradiation, as well as determining the concentrations of various types of defects depending on the irradiation fluence. It was found that in the case of two-component lithium-containing ceramics, the resistance to accumulation of radiolysis products is due to the effects of the presence of interphase boundaries that inhibit the formation of radiolysis products. According to the qualitative assessment of the EPR spectra, it was established that in the case of two-component ceramics, the formation of HC 2 – centers occurs at higher irradiation fluences (above 5 × 10 20 neutron/cm 2 ), while for one-component ceramics, the formation of radiolysis products is observed at irradiation fluences above 10 19 neutron/cm 2 . In this case, a comparative analysis of the concentrations of defects formed in the damaged layer and their evolution indicates an increase in resistance to defect formation processes due to a change in the ratio of components in the composition of two-component ceramics. The improved stability of two-component ceramics against disordering and defect accumulation is attributed to grain boundaries, which act as barriers to oxygen vacancy migration and defect clustering.