PNNL

Abstract

Judd-Ofelt (JO) derived oscillator strength parameters (?2, ?4, ?6) of electronic transitions of the trivalent lanthanides (Ln) qualitatively describe local Ln environment. Recently, we have systematically studied the parameters, or JO parameters, as a function Nd concentration in a single Na-rich aluminoborosilicate glass. Based on Nd partitioning scheme as its dissolution mechanism for borosilicate glasses, we simulated extent of borate saturation as a function of Nd concentration by applying a stable local Nd-metaborate structure derived from our previous studies. The best results concluded that the first onset of the ?2 discontinuity resulted from the saturation of the borate sites by Nd. Combining with our earlier study of the JO parameters for Al-rich borosilicate glass without Na, we can further conclude that the index of saturation of boron by Nd, IS[B] = [Nd2O3]B-site/1/3{[B2O3]ex + [Al2O3]ex}, provides a general physical description of Nd partitioning in the borate site for complex Na2O-Al2O3-B2O3-SiO2 glasses, whereas for the Na-rich glass reported in this study, [Al2O3]ex = 0.