Effect of alkaline-earth ions on the physical and optical properties of bismuth based glasses

Bismuth based quaternary oxide glass series 10LiF-40Li2O-20RO-30Bi2O3 where R= Mg, Ca, Sr& Ba have been prepared by the melt quenching method. Physical parameters such as density, glass transition temperature, optical energy gap and refractive index of prepared glasses were evaluated. It was found that, the densities of the glass increased in the order of MgO CaO>SrO>BaO. The decrease in Tg is attributed mainly due to the field strength in the order MgO>CaO>SrO>BaO. The optical band gap (Eopt) values decreased with the replacement of RO oxides in the glass matrix. The values of electronic polarizability, optical basicity and interaction parameters of the glass were determined. The increment of refractive index values in these glasses is attributed to the substitution of alkaline earth oxides of increasing mass. The decrease in optical band gap values and consequently increase in Urbach’s energies confirms the extension of the localized states within the band gap. As a result there shall be an increase in the disorder of the glass network. The variation in optical parameters is owing to the substitution of RO oxides in the present glass network.Bismuth based quaternary oxide glass series 10LiF-40Li2O-20RO-30Bi2O3 where R= Mg, Ca, Sr& Ba have been prepared by the melt quenching method. Physical parameters such as density, glass transition temperature, optical energy gap and refractive index of prepared glasses were evaluated. It was found that, the densities of the glass increased in the order of MgO CaO>SrO>BaO. The decrease in Tg is attributed mainly due to the field strength in the order MgO>CaO>SrO>BaO. The optical band gap (Eopt) values decreased with the replacement of RO oxides in the glass matrix. The values of electronic polarizability, optical basicity and interaction parameters of the glass were determined. The increment of refractive index values in these glasses is attributed to the substitution of alkaline earth oxides of in...