Optical Absorption and Thermo luminescence of Manganese-Doped CaF2, Single Crystals Irradiated with X-Rays

Optical absorption in the region 220 to 800 nm and thermoluminescence of X-ray-irradiated CaF, single crystals were measured. Similar measurements were also taken on manganese-doped CaF2 crystals (with 0.2, 1, and 5 mol% of manganese content). The thermal bleaching characteristics of colour centres in CaF2:Mn samples have been investigated. Two features are observed in manganese-doped CaF2 crystals after X-ray irradiation (in comparison to X-ray-irradiated CaF2): (i) an enhancement of colorability with increasing Mn content and (ii) formation of a- and (3-bands in CaF2:Mn (1%) and also new absorption bands in CaF2:Mn (5%). A new absorption band at 300 nm obtained in the X-ray-irradiated CaF2:Mn (5%) may probably be connected with Mn centres. The thermoluminescence of CaF2 is considerably affected with manganese doping. An attempt has been made to understand these results.