On the mechanisms of radiation damage and prospects of their suppression in complex metal oxides

The influence of some impurity ions on the increase/decrease in the resistance against irradiation of metal oxides with X‐rays and electrons (low‐dense excitation) or ∼2 GeV Au$^{198}$ and U$^{238}$ ions providing a superhigh density of electronic excitations along cylindrical tracks (LET > 30 keV nm$^{−1}$) has been investigated for fcc MgO single crystals with close ion masses or Lu$_3$Al$_5$O$_{12}$ and Gd$_2$SiO$_5$ with large unit cells and heavy cations. The radiation effects have been studied using the methods of low‐temperature vacuum ultraviolet spectroscopy (up to 40 eV), cathodoluminescence and thermoactivation spectroscopy. The step‐by‐step annealing of the radiation‐induced absorption, scattering, and luminescence has been performed at the heating of irradiated crystals up to ∼70% of a melting point. Possible experimental manifestations of the temperature‐stable nanosize 3D defects created, according to theoretical predictions, via rearrangement of many host ions at the collapse of discrete solitons (breathers) are detected in Lu$_3$Al$_5$O$_{12}$ and Gd$_2$SiO$_5$ crystals irradiated with swift heavy ions (fluence of 10$^{12}$ ions cm$^{−2}$)