Temperature effect on fluorescence and UV-vis absorption spectroscopic properties of Dy(III) in molten LiCl-KCl eutectic salt

Abstract

The spectroscopic properties of Dy(III) in molten LiCl-KCl eutectic salt at high temperature were investigated by time-resolved laser fluorescence spectroscopy (TRLFS) and UV-vis absorption spectroscopy. For the first time, a visible fluorescence of Dy(III) in high-temperature LiCl-KCl eutectic salt was measured due to the electronic transitions from I-4(13/2) and F-4(9/2) to H-6(J/2) (J=7, ... , 15). The effect of temperature on hypersensitivity for the electronic transitions from the I-4(13/2) excited state (similar to 25700 cm(-1)) of Dy(III) was confirmed by altering temperature in chloride eutectic salt in accord with optical absorption measurements. The molar absorptivity of I-4(13/2) <- H-6(15/2) was enhanced with increasing temperature. The fluorescence intensity of Dy(III) followed a simple mono-exponential decay curve, suggesting the formation of a single chemical species in high-temperature LiCl-KCl molten salt. (C) 2012 Elsevier B.V. All rights reserved.