Growth and optical characterization of Pb-, Tl-doped LiF crystals

Large and transparent LiF:Pb and LiF:Tl crystals were successfully grown by using Kyropoulos method. They were characterized using spectroscopic measurements combined with differential thermal analysis and thermogravimetry (TG) analysis, in order to investigate the effect of dopants upon the optical properties of these crystals. The optical absorption peaks at 278 nm (for Pb) and 273 nm (for Tl) have been assigned to the A-type transition of these ions. Photoluminescence spectra have shown bands at 350 nm (for Tl) and 375 nm (for Pb), which have been associated to the dopant ions in different configurations in the lattice.