Energy transfer between manganese(II) and thulium(III) in transition-metal fluoride glasses

Abstract

Lead zinc gallium fluoride glass containing 2 mole% TmF 3 is shown to luminesce from 1I 6 (35200 cm −1), 1D 2(28000), 1G 4 (21500) and 3H 4 (12800) to several lower J levels. When the 24 mole% ZnF 2 is replaced by MnF 2 in the absence of thulium, the (broad band) quartet-to-sextet (ground state) emission at 16800cm −1 has a mean lifetime of 1 ms. If 2 mole% TmF 3 is added to the latter glass, energy transfer decreases the lifetime to below 0.03 ms. The high critical radius R 0 (above 20 Å) is rationalized by Mn-Mn energy migration (concomitant with a lifetime shortened from 24 ms) to be compared with R 0≈ 8 Å for low Mn(II) concentration, almost identical with energy transfer between 1 mole% each of MnF 2 and NdF 3 previously studied in an analogous glass.