Changes of thermodynamic quantities at the glass transition

Abstract

Based on a microscopic approach we present results for the changes in thermodynamic derivatives at the glass transition. These changes are expressed in terms of correlation functions of the frozen out microscopic pressure and energy fluctuations. Quantitative results for the discontinuities as well as the Prigogine–Defay ratio are obtained within a simple model and agrees quite well with experimental results. A generalized order parameter is identified in terms of a correlation function, describing the frozen in local structure of the glass.