Thermal analysis of Li2O TeO2 glass

The thermal properties of 0.30Li2O · 0.70TeO2 glass are studied. Specific heat, Cp, is measured in the 170°C<T<270°C interval. The Einstein temperature, θA=840 K, is determined from the temperature course of Cp. In the glass transition interval, the heat capacity undergoes an S-shaped transition from the value, Cgl, of the glass to that of undercooled melt, Cp. It is found that Cgl/Cp≈0.62. The activation energy, E(Tf), for structural relaxation depends on a fictive temperature, Tf. For the glass under study, it is demonstrated that: E(Tf)=655+300(520Tf−1) kJ/mol.