Direct observation of Nd3Â + and Tm3Â + ion distributions in oxy-fluoride glass ceramics containing PbF2 nanocrystals

Nd3 + and Tm3 +, doped oxy-fluoride glasses and glass ceramics were prepared by conventional melt-quenching and subsequent heat-treatment, respectively. β-PbF2 nanocrystals with diameter 50 -100 nm formed in the glass matrix after heat treatment. The Stark splitting in absorption peaks, enhanced photoluminescence and prolonged lifetimes that β-PbF2 nanocrystal formation increased the luminescence of rare earth ions. Both Nd3 + and Tm3 + ions were incorporated into nanocrystals that were enriched in lead and fluorine, and deficient in oxygen.