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The Prigogine-Defay ratio revisited
Jürn W P Schmelzer1, Ivan Gutzow
1Institut für Physik, Universität Rostock, 18051 Rostock, Germany. juern-w.schmelzer@physik.uni-rostock.de
The Journal of Chemical Physics
|November 23, 2006
Summary
The Prigogine-Defay ratio, crucial for understanding glass transition, was rederived using irreversible thermodynamics. This study shows the ratio typically exceeds 1 during vitrification, aligning with experimental data.
Area of Science:
- Thermodynamics
- Materials Science
- Physical Chemistry
Background:
- The Prigogine-Defay ratio characterizes the glass transition, linking key thermodynamic properties.
- Previous derivations often oversimplified vitrification as an instantaneous process.
Purpose of the Study:
- To rederive the Prigogine-Defay ratio using irreversible thermodynamics and a single order parameter.
- To account for the non-equilibrium nature of vitrification over a temperature interval.
Main Methods:
- Application of de Donder and van Rysselberghe's order-parameter concept.
- Analysis within the framework of thermodynamics of irreversible processes.
- Utilizing a mean-field lattice-hole model for quantitative estimates.
Main Results:
- The Prigogine-Defay ratio is generally greater than 1 during cooling-induced vitrification.
- Quantitative estimates were derived using a specific lattice-hole model.
- Consequences for thermodynamic coefficients like Young's modulus were explored.
Conclusions:
- The rederived Prigogine-Defay ratio provides a more accurate description of glass transition.
- Theoretical predictions show good agreement with experimental observations.
- The study highlights the importance of considering non-equilibrium effects in vitrification.
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