Polyamorphism in glassy network materials

Area of Science:

• Condensed Matter Physics
• Materials Science
• Physical Chemistry

Background:

• Network liquids display polyamorphism, featuring multiple liquid phases due to competing local structures.
• Thermal bond breaking drives phase transitions, causing anomalies like water's density maximum.
• Studying polyamorphism in water is challenging due to crystallization and glassy effects.

Purpose of the Study:

• To develop a microscopic model for calculating glassy and thermodynamic properties of network liquids.
• To investigate the interplay between polyamorphism and glassy properties using Random First Order Transition (RFOT) theory.
• To understand how glassy dynamics influence phase transition kinetics and thermodynamic anomalies.

Main Methods:

• Development of a simple microscopic model based on microscopic potentials.
• Application of Random First Order Transition (RFOT) theory to analyze the glass transition.
• Tuning model parameters to simulate water-like phase diagrams and analyze nucleation phenomena.

Main Results:

• The model successfully reproduces liquid-liquid phase transitions, tunable relative to the glass transition.
• A direct link was established between thermodynamic anomalies (e.g., water-like) and glassy kinetic anomalies.
• When mimicking water's phase diagram, liquid-liquid transitions near the glass transition exhibit "nanonucleation".

Conclusions:

• Glassy dynamics significantly modify phase transition kinetics in network liquids.
• The study provides insights into the nonclassical nucleation properties of liquid-liquid phase transformations near the glass transition.
• The model offers a framework for understanding polyamorphism and its connection to glassy behavior in materials like water.