Diffusion and aggregation of subsurface radiation defects in lithium fluoride nanocrystals

Abstract

Lithium fluoride nanocrystals were irradiated by gamma rays at a temperature below the temper ature corresponding to the mobility of anion vacancies. The kinetics of the aggregation of radiation induced defects in subsurface layers of nanocrystals during annealing after irradiation was elucidated. The processes that could be used to determine the activation energy of the diffusion of anion vacancies were revealed. The value of this energy in subsurface layers was obtained. For subsurface layers, the concentrations ratio of vacan cies and defects consisting of one vacancy and two electrons was found. The factors responsible for the differ ences in the values of the activation energies and concentration ratios in subsurface layers and in the bulk of the crystals were discussed.

Auto-ionization of LiF grains

“…At room temperatures, there is no diffusion of defects consisting of two vacancies and one electron in subsurface layers. As a result, the concentration of these defects remains constant for a long time if the sample is stored at the room temperature [8]. In the study, we performed the experimental investigations of autoionization on LiF because its characteristic properties can be more pronounced.…”