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

Abstract The characteristics of the laser-induced fluorescence of Nd 3+ 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, Nd 3+ in molten salt emits visible and near-IR fluorescence. The fluorescence peaks at 750 nm ( 4 F 7/2  +  4 S 3/2  →  4 I 9/2 ) and 810 nm ( 4 F 5/2  +  2 H 9/2  →  4 I 9/2 ) 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 Nd 3+ coexist in this system.