Thermodynamical approaches to the glass transition

Abstract

The problem of the glass transition is approached from the thermodynamical viewpoint, with particular reference to the Prigogine-Defay ratio Γ. Some controversial points concerning the condition Γ>1 are shown to be irrelevant from the phenomenological viewpoint. The importance of the internal energy at the glass transition is emphasized. Accordingly, a thermodynamical model, based on fluctuating internal stresses, is proposed and applied to a class of Ge_xSe_1-x liquids.