Kinetics of the electronic center annealing in Al₂O₃ crystals

The experimental annealing kinetics of the primary electronic F, F⁺ centers and dimer F₂ centers observed in Al₂O₃ produced under neutron irradiation were carefully analyzed. The developed theory takes into account the interstitial ion diffusion and recombination with immobile F-type and F₂-centers, as well as mutual sequential transformation with temperature of three types of experimentally observed dimer centers which differ by net charges (0, +1, +2) with respect to the host crystalline sites. The relative initial concentrations of three types of F₂ electronic defects before annealing are obtained, along with energy barriers between their ground states as well as the relaxation energies.