Laser-Induced-Time-Resolved Fluorescence (LIF) Spectroscopic Study of Lanthanide Element Chemical Environments in Alkali Free Borosilicate Glasses
EMSL Project ID
1628
Abstract
Gadolinium oxide (Gd2O3) is one of the neutron absorbers Gd2O3, Sm2O3, and HfO2) that can be used in borosilicate glasses for immobilization of plutonium containing wastes. A recent study suggests that Gd(III) may be a good surrogate for Pu(III) in alkali borosilicate glass. Cerium oxide (CeO2 and Ce2O3) in alkali-borosilicate glasses was shown to have a similar solubility behavior to plutonium. Specifically, Ce and Pu are more soluble in alkali borosilicate glasses at a tri-valent oxidation state than a tetra-valent state. Both alkali and alkali free borosilicate glasses are considered for immobilization of actinide such as Pu, Am, and Cm. Therefore, studying lanthanide elements, in general, can be important to understanding the structure roles of Pu(III), Am(III), and Cm(III) in glasses with and without alkali metal cations. The results from an ongoing research collaboration with EMSL staff on Gd in alkali borosilicate glasses show that laser-induced-time-resolved fluorescence (LIF) technique can be used to study the phenomenon of Gd clustering in alkali borosilicate glasses. Based on these encouraging results, we further propose to study Gd, Nd, and Ce in alkali free borosilicate glasses using LIF. The use of Nd allows us to study structure of Nd by using both LIF and UV-VIS optical absorption spectroscopic techniques, whereas Gd and Ce cannot be probed using UV-VIS spectroscopy. In conjunction with the previous study of Gd in alkali borosilicate glasses, the results from this part of study may provide significant contribution to a fundamental understanding of solubility of rare earth elements in glasses with and without alkalis, which will have a direct implication for explaining solubility of Pu(III), Am(III), and Cm(III) in borosilicate glasses. The LIF results obtained from this study will be published in peer reviewed journal paper.
Project Details
Project type
Exploratory Research
Start Date
1999-07-09
End Date
2000-12-29
Status
Closed
Released Data Link
Team
Principal Investigator