Spectroscopic study of carbonate retention in high-basicity borate glasses

• Published in: Journal of non-crystalline solids 1989-11, Vol.111 (2), p.252-262
• Main Authors: Kamitsos, E.I., Karakassides, M.A., Patsis, A.P.
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Infrared and raman spectra and scattering; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Physics
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/0022-3093(89)90288-3

Raman and infrared spectroscopic techniques have been employed to investigate the carbonate retention in high alkali content sodium- and lithiumborate glasses: xM 2 O·(1 − x)B 2 O 3 ( x = 0.65, M = Li; x = 0.65, 0.71, M = Na. Spectroscopic evidence for carbonate retention was found only in sodiumborate glasses for three glass compositions studied here. It was shown that carbonate species are present in the glass as CO 3 2− ions which are perturbed through interactions with the glassy environment. Decreasing the concentration of carbonates in the glass, by longer melting times and higher melting temperatures, was found to induce significant structural changes in the borate network. These were manifested by the destruction of certain borate groups and the creation of new ones, which are favoured under conditions of higher glass basicity. The specific structural rearrangements were found to depend strongly on the alkali oxide content. The concentration of carbonate and various borate species has been investigated as a function of melting time, and found to follow a two-step exponential dependence. Modification schemes describing the changes of the borate network have been proposed on the basis of the spectroscopic results.