Kinetics of dimer F2 type center annealing in MgF2 crystals

Abstract

In this paper, we analyzed experimental annealing kinetics of the primary electronic F centers and dimer F2 centers observed in MgF2 at higher radiation doses and temperatures. The developed phenomenological theory takes into account the interstitial ion diffusion and recombination with the F2-centers, as well as mutual sequential transformation with temperature growth of three types of experimentally observed dimer centers: F2(1), F2(2), F2(3) (which differ tentatively by charges (0, +1, +2) with respect to the host crystalline sites). The results of the electron, neutron and ion irradiation are compared. As the result, 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.