Distribution of Pb²⁺Ions in PbF₂-Doped CaF₂Crystals

Abstract

Calcium fluoride crystals doped with various concentrations of PbF 2 have been grown using the Bridgman technique. The optical absorption spectra reveal the characteristic UV absorption bands of the Pb 2+ ions. The distribution of the Pb 2+ -ions along four crystals has been investigated using the optical absorption method. Taking into account the relationship between the optical absorption coefficient and the concentration of the impurities in the samples, the effective segregation coefficient of the Pb 2+ ions has been calculated. Our study shows that the effective segregation coefficient of the Pb 2+ ions in CaF 2 host depends on the dopant concentration, and varies between 0.85 and 1.15, for 0.5 mol%PbF 2 and 3 mol%PbF 2 -doped CaF 2 , respectively.

Investigation of luminescence properties of Pb2+‐doped Sr2B2O5 phosphor

“…The lowest energy 1 S 0 → 3 P 0 transition is strongly forbidden, but the 1 S 0 → 3 P 1 transition and the 1 S 0 → 3 P 2 transition become more allowed due to spin‐orbit coupling and coupling to asymmetrical phonon modes, respectively. The 1 S 0 → 1 P 1 transition is an allowed electric dipole transition …”

“…1 P 1 transition is an allowed electric dipole transition. 17,18 Figure 3 shows the excitation and emission spectra of the undoped-Sr 2 The excitation band of the synthesized phosphor Sr 2Àx Pb x B 2 O 5 (x = 0.025) was observed at 289 nm, which is assigned to the 1 S 0 ? 3 P 1 transition.…”

Segregation coefficient of Yb3+ and Yb2+ ions in YbF3 doped BaF2 crystals

“…The effective distribution coefficient, k ef , has been determined using the optical absorption method [6][7][8]. In order to investigate the dopant concentration along the crystals and to determine the segregation coefficient, the crystals were cut from the bottom to the top into i = 9 slices.…”

“…The value of C S can be measured by various methods, or estimated from optical absorption measurements [6][7][8] as described below.…”

Growth and Characterization of Doped CaF2 Crystals

“…In order to obtain high Yb 3+ -Yb 2+ conversion in the as grown crystals, we have developed a special growth procedure. Rare-earth ions -doped and PbF 2 -codoped CaF 2 crystals were grown using vertical Bridgman method [Nicoara et al, 2006a[Nicoara et al, , 2006b[Nicoara et al, , 2008a[Nicoara et al, , 2008b[Nicoara et al, , 2008cPruna et al,2009;Paraschiva, 2010]. As starting materials suprapure grade calcium fluoride, YbF 3 , ErF 3 and PbF 2 have been used.…”