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

Abstract

Abstract. BaF 2 :0.17 mol%YbF 3 crystal was grown using the conventional Bridgman technique. The optical absorption spectra reveal the existence of both Yb 2+ and Yb 3+ ions with the characteristic bands of the trivalent ions in the near-IR region and of the divalent ions in the UV spectral domain. The concentration distribution of the Yb 2+ and Yb 3+ ions among the sample was investigated using the optical absorption method. The segregation coefficient of the two types of Yb ions has been determined. From our calculations the segregation coefficient of the Yb 3+ ions in BaF 2 host is ≈ 0.7, and of the Yb 2+ ions is ≈ 0.6.

The Impact of BiF3 Doping on the Yb3+ to Yb2+ Reduction during the LiYF4:Yb3+ Crystal-Growth Process

“…The dopant concentration is proportional to the absorption coefficient, and their distribution can be described by the Gulliver-Pfann law [24]:…”

“…Several studies devoted to the investigation of Yb 2+ distribution along fluoride crystals found that the segregation coefficient of Yb 2+ in YbF 3 :CaF 2 crystals varies from 0.68 to 0.74, depending on Yb concentration [26]. In YbF 3 :BaF 2, the segregation coefficient of divalent ytterbium equals 0.59 [24]. The implementation of formula (1) on the dependencies in Figure 6 gives the effective-distribution-coefficient values 0.98 and −0.7 for Yb 3+ and Yb 2+ , respectively.…”