Thermoluminescence and Color Centers in LiF:Mg

Abstract
A variety of optical absorption, emission and luminescence excitation spectra have been measured in an attempt to identify the centers involved in the thermoluminescence of commercial LiF:Mg. It is concluded that the principal trapping centers consist of a hole trapped near various groupings of Mg2+ ions and vacancies. The optical absorption bands of these centers occur in the 3100–3800 Å region which contains several absorption bands corresponding to different geometries of the centers. It is suggested that the 2200-Å band arises from Mg2+ ion-vacancy complexes which have captured two holes. During thermoluminescence, holes are transported from traps to emitting centers. The luminescent center appears to be the F center both in an isolated position and when adjacent to a complex involving Mg2+ ions.