F-Centers in BaBrI Single Crystal

In this article, we demonstrate the results of experimental and theoretical studies of F-centers in BaBrI single crystals. We have observed two types of F-centers related to an electron trapped in the iodine or bromine vacancy site. It was found that absorption bands due to F-centers can be induced either by radiation or additive coloration. The excitonic mechanism of F-center production was established and demonstrated. Optical properties of the F-centers in a monoclinic symmetry environment have been calculated by means of the embedded cluster method.