Effect of lithium fraction f_Li on glass transition temperature T_g and ionic conductivity σ of lithium borosilicotitanate glasses

Abstract Three different lithium borosilicate glass systems with TiO2 addition have been synthesized by melt quenching technique. The XRD was done for all glass samples to confirm their amorphous nature. Electrical conductivity (σ) of these glasses has been studied by dielectric impedance analyzer as a function of frequency at different temperatures in the range 480 to 650 K. Glass transition temperature Tg for the glasses has been determined by using DTA. The density of all glass samples has been determined. It has been observed that the electrical conductivity increases with increasing content of TiO2 which can be attributed to the modification of the structure by the addition of larger titanium ions. It is observed that higher lithium fraction fLi content glass series has highest conductivity. A good correlation is observed between the ionic conductivity, glass transition temperature and lithium fraction of the glasses. The analysis of IR spectra reveals the presence of Ti ions in tetrahedral TiO4 units as well as creation of NBOs, which supports the conductivity results.