Luminescence and thermal stability of $F$-type defects in sapphire irradiated with pulsed ion beams

Luminescence and thermal stability of defects formed in $\alpha$-Al$_{2}$O$_{3}$ single crystals under pulsed ion beam treatment (C$^+$/H$^+$ ions with an energy 300 keV, pulse duration 80 ns) were investigated. This type of irradiation leads to the intensive generation of both single $F$- and $F^+$-centers and more complex defects ($F_2$-type aggregate centers or vacancy-impurity complexes) in $\alpha$-Al$_{2}$O$_{3}$. It was confirmed by the results of optical absorption, photoluminescence, and pulsed cathodoluminescence measurements. The thermal stability of $F$-type defects formed in $\alpha$-Al$_{2}$O$_{3}$ under the pulsed ion beam treatment is comparable to the stability of radiation-induced defects in neutron-irradiated samples.