Raman spectroscopic study of gadolinium(III) in sodium-aluminoborosilicate glasses

A Raman spectroscopy study was performed on a series of sodium-aluminoborosilicate glasses with Gd2O3 from 0 mass% up to its solubility (47 mass% or 13.58 mol%). Experimentally measured spectra were fitted with a Gaussian function for each individual band without any restriction on the band position, width, and intensity. The evolution of the spectroscopic bands appears to result from partitioning of the rare earth cation, as its dissolution mechanism, in these borosilicate glasses. Specifically, the evolution of the Raman bands was correlated well with Gd cations partitioning in the borate-rich environment at low Gd2O3 concentration, Gd2O3/[1/3B2O3]<1, and excess Gd cations, Gd2O3–1/3B2O3, in the silicate-rich environment at high Gd2O3 concentration, Gd2O3/[1/3B2O3]>1. Raman bands near 1420 and 710 cm−1 suggest the presence of a local Gd-metaborate environment, which appeared to occur at all Gd2O3 concentrations. The bands near 300 and 910 cm−1 further suggest the formation of Gd–O–Gd clusters in the silicate-rich environment at high Gd2O3 concentrations.