Optical transitions of Ni²⁺and radiation defects in MgF₂and MnF₂

Abstract

A study has been made of the absorption, emission and excitation spectra of transitions in nickel-doped MgF2 and MnF2. The temperature dependence of the lifetimes of these transitions has been recorded. For the case MgF2:Ni2+, a complete configuration coordinate model has been determined for this crystal using the method of Struck and Fonger (1974). Similar observations have been made for MnF2:Ni2+, but energy transfer between Mn2+ ions and Ni2+ ions reduces the amount of information available for completion of the model. It is found that the infrared luminescence intensity of MnF2:Ni2+ for excitation in the visible region (400-600 nm) is twice that of MgF2:Ni2+. No observable changes occurred in the Ni2+ optical transitions when these crystals were irradiated with 1.7 MeV electrons.