Electrochemical and spectroscopic investigations of Tb(III) in molten LiCl-KCl eutectic at high temperature

Electrochemical and spectroscopic properties of Tb(III) in molten LiCl-KCl eutectic at high temperature were investigated by cyclic voltammetry and time-resolved laser-induced fluorescence spectroscopy (TRLFS). The diffusion coefficient of Tb(III) and the formal standard potential of Tb(III)/Tb-0 were determined to be 2.06 +/- 0.4 x 10(-5) cm(2) s(-1) and -2.83 +/- 0.03 V vs. Cl-2/Cl- at 887 K, respectively. Additionally, visible fluorescence of Tb(III) due to the electronic transitions from D-5(3) and D-5(4) to F-7(J) was observed and measured by TRLFS for the first time. These results provide the first fluorescence spectroscopic evidence for a direct in situ quantification of Tb(III) in the high temperature molten salt system. (C) 2010 Elsevier B.V. All rights reserved.