Influence of neutron irradiation conditions on maximal frequency of IR absorption spectra of LiF:OH single crystal

For many solids operating under irradiation conditions, the study of their behavior at the neutron irradiation is of importance. Herein, the influence of neutron irradiation conditions on the infrared (IR) absorption spectra of LiF crystals containing different amounts of hydroxyl and metallic impurities is considered. The investigations are carried out for discovering new peculiarities under the extreme irradiation conditions of LiF---being a very important material for practical applications. In the crystals with OH${}^{-}$ impurity after the action of neutron irradiation, quite clear bands are appeared in the region of 1900-2200 cm${}^{-1}$. The delivered doses vary from 10${}^{14}$ to 3 × 10${}^{17}$ nnvt. LiF crystals are investigated by differing both in qualitative and quantitative contents of OH${}^{-}$ ions. With the increase in irradiation dose, the maximum IR absorption of all investigated groups of crystals shifts to the region of low energies. The appearance of a new band in the IR spectrum and its shift as a function of dose is associated with the radiolysis of OH${}^{-}$ molecule. (© 2023 Wiley‐VCH GmbH)