A simple phenomenological model for the order parameter description of glass transition

Summary

Glass transition has been investigated as a freezing-in process by using a simple form of the Gibbs free energy with two order parameters. Two cases are examined: that of a single freezing-in line (transition line) and that involving two different lines on which the individual order parameter freezein gradually. The latter case is a simple, but adequate description of the diffusivity of glass transition. The effect is discussed of the mutual position of freezing-in lines and of the Prigogine-Defay ratio on the dependence of the behaviour of material on the thermodynamic history of glass transition.