Raman study on B2O3-CaO glasses

Glasses are of special interest nowadays mainly because of the large applications that they span. Raman spectroscopy is an experimental technique appropriate for providing information about the structure of local arrangements of the atoms in glasses. The influence of CaO content on the structure of borate glasses was investigated by Raman spectroscopy. At low calcium oxide content the structure of calcium borate glass consists mainly of boroxol groups and a smaller number of pentaborate groups. In the vitreous network there are few diborate groups, chain type metaborate groups and pyroborate groups. At high calcium oxide content, pentaborate, orthoborate and metaborate groups appear. The increase of calcium oxide content yields an increase in number of non-bridging oxygen ions. Therefore, we conclude that calcium ions act as network modifiers in borate glasses. (C) 2003 Elsevier Science B.V. All rights reserved.