Structural Investigation, Physical and Optical Properties of Mixed Alkali Bismuth Borate Glasses

Lead free, eco-friendly bismuth borate glasses doped with alkali oxides of composition xLi2O(30-x)Na2O瘻羵똻 (x = 5,10,15,20,25) were prepared by melt quenching technique. Amorphous nature of glasses was confirmed by X-ray diffraction. Density measurements were carried out at room temperature by standard principle of Archimedes with Xylene as an immersion liquid. The non-linear behavior of density, molar volume, glass transition temperature, direct and indirect optical band gaps confirm the mixed alkali effect. The FTIR analysis revealed that the network structure consists of BO3, BO4 units and BiO6 octahedral units. UV-vis spectroscopy shows no sharp absorption edges giving a clear indication of the amorphous nature of the glasses.