Effect of an addition of TiO₂ on the thermal stability of Li₂O.SiO₂ glasses -application of various criteria

Abstract

To compare the thermal stability of Li₂O.2SiO₂ and Li₂O.2SiO₂.0.1TiO₂ glasses, various criteria have been used. Not only characteristic temperatures, values of activation energy (E) and enthalpy changes (ΔΗ), but also the combined criteria E/RT and k_f(T) = A exp [(-E/RT) (T_p-T_f)/T_f] (T_p is the maximum peak temperature, T_f is the inflection point temperature on the differential thermal analysis curves) have been taken into account. The results indicate that order of the thermal stability against of different glass systems crystallization depends not only on their composition but also on the mechanism of crystallization which is connected with the used parameter.