Vibrational spectra and structure of mixed alkali borotungstate glasses: Evidence of mixed alkali effect

Mixed alkali borotungstate glasses with xLi2O-(30 − x)Na2O-10WO3-60B2O3 (0 ≤ x ≤ 30) composition were prepared by melt quench technique. FT-IR and Raman spectroscopic studies were employed to investigate the structure of all the prepared glasses. Acting as complementary techniques, both IR and Raman measurements revealed that the network structure of the present glasses mainly based on BO3 and BO4 units placed in different structural groups. Raman spectra confirm the IR results regarding the presence of tungsten ions mainly as WO6 groups. In the present work, the mixed alkali effect (MAE) has been investigated in the above glass system using FTIR and Raman studies.