Suitability of Nd(III) absorption spectroscopy to probe the structure of glasses from the ternary system Na 2O–B 2O 3–SiO 2

Abstract

Optical absorption spectra of glasses from the ternary system Na 2O–B 2O 3–SiO 2 with 20, 40, and 60 mol% SiO 2 and varying modifier contents containing 1 mol% Nd 2O 3 were measured at cryogenic temperatures. The glasses were obtained by quenching the liquids of appropriate composition between steel plates. For comparison doped glasses from the binary systems Na 2O–B 2O 3 and Na 2O–SiO 2 were included. The molar volumes and packing ratios of the doped ternary glasses were compared with those of undoped glasses with similar composition to make sure that the dopant ions do not affect the bulk glass properties. The position of the 4I 9/2 → 2P 1/2 transition was used to monitor the nephelauxetic effect and the hypersensitive 4I 9/2 → 4G 5/2, 2G 7/2 transition to monitor changes in the rare-earth environment with the glass composition. The observed changes of the spectral features are consistent with structural changes in the host glasses as proposed by models of these glasses derived from NMR and IR investigations on undoped glasses. Hence the suitability of Nd 3+ absorption spectroscopy to probe the structure of these glasses is established.