Positron annihilation Lifetime and Fourier transform infrared spectroscopic studies on Bi2O3–B2O3 glasses

Bismuth borate glasses with compositions x (Bi2O3)×(100−x) (B2O3) (where x is in mol. % ranging from 25 to 50 in steps of 5) have been prepared by using melt quenching technique. The glass transition temperature (Tg) of the prepared samples has been measured. It was found that the glass transition temperature (Tg) decreases with increasing Bi2O3 content which indicates that the degree of disorder increases.