Raman spectroscopic investigations on oxide glass system (1-x)[3B(2)O(3)center dot K2O]center dot xTiO(2)

The influence of TiO2 content on the structure of 3B(2)O(3). K2O glass was investigated by Raman spectroscopy. First, the addition of titanium oxide d oes not determine any structural changes in studied glasses. For x less tha n or equal to 0.1 Raman spectra indicate that studied glasses contain mainl y pentaborate groups and boroxol rings. At a high concentration of titanium oxide the number of nonbridging oxygens increases and the glass structure becomes more randomised. For x > 0.1 TiO2 ring type metaborate groups and " loose" BO4- tetrahedra appear. A small number of chain-type metaborate and pyroborate groups are also present in this kind of glass. Therefore, we conclude that titanium ions act as network modifiers in these glasses only at high concentration. (C) 1999 Elsevier Science B.V. All rig hts reserved.