PHOTOLUMINESCENCE OF KMGF3TL+

Luminescence of T1+ impurity ions in single crystals of KMgF3 is measu red under various optical excitations in the v.u.v. between 110 and 20 0 nm. The A' emission at 212 nm is observed under optical pumping in t he A (203 nm), B (168 nm) and C (150nm) absorption bands of Tl+ ions. The B' emission at 183 nm is accompanying the A' luminescence under ex citation in the B and C absorptions. The decay kinetics of the A' emis sion, optically stimulated in the A absorption band, consists of two d istinct exponential components (tau(f) = 9 ns and tau(s) = 14 ms, resp ectively, at low temperatures). Such results reveal a strict analogy w ith those known for Tl+ in alkali halides, in spite of different coord ination spheres for the impurity ions. Peculiar features in KMgF3:Tlare the anomalous temperature dependence and the small Stokes shift of the A' emission, and a further luminescence at 243 nm which could be due to intrinsic deexcitation processes in the host material.