Crystallization of Na- and Cs-Bearing Borosilicate Melts: Results of Raman Spectroscopy

The structure of borosilicate glass and glass-ceramic materials of two compositions with different Cs/Na ratios was studied using Raman spectroscopy. The materials were synthesized in two different modes. The anionic environment of cesium in the glass and the structural rearrangements of the network during the formation of crystalline phases have been studied. X-ray diffraction patterns of glass-ceramic samples made it possible to determine the only crystalline phase CsBSi2O6, the structure of which was not clearly determined. The glass-ceramics of the studied composition can be used to immobilize cesium by incorporating it into the crystalline phases of the CsBSi2O6 composition, while sodium is retained in the glassy matrix. These studies showed that the composition of the crystalline phase does not depend on the initial ratio of alkali cations, while the proportion of the ordered and amorphous phases is controlled by the kinetics of the melt cooling process.