Abstract
The viscosity-temperature relationships for metaphosphate glass and polystyrene in the wide-temperature range, including below the glass transition temperature Tg, obtained by us, were analyzed using the Adam-Gibbs theory. The results showed that the glass transition is a non-equilibrium phase transition from the Vogel-Tammann-Fulcher (VTF) state to the Arrhenius state occurring at Tg. The Arrhenius curves below Tg show different slopes with varying activation energies owing to the fictive temperatures Tf characterizing the structural states of the glasses. To explain this result from the microscopic viewpoint, a model of an intermediate range order (IRO) is proposed. We also propose that the glass transition is due to a self-organization of the IROs, a few nanometers in size, in the glass state.
