Time-resolved laser-induced fluorescence spectroscopy of Nd3+ in molten LiCl–KCl eutectic

The characteristics of the laser-induced fluorescence of Nd3+ in LiCl–KCl eutectic in the wavelength region of 360–900 nm were investigated for information concerning the chemical speciation of Nd-chloride complexes. When pumped at either 355 or 532 nm, Nd3+ in molten salt emits visible and near-IR fluorescence. The fluorescence peaks at 750 nm (4F7/2 + 4S3/2 → 4I9/2) and 810 nm (4F5/2 + 2H9/2 → 4I9/2) were particularly prominent at temperatures above the melting point. The fluorescence decay of these transition lines showed a bi-exponential behaviour of the fluorescence lifetime. These results provide evidence that two different chemical species of Nd3+ coexist in this system.