An energy-landscape-based crossover temperature in glass-forming liquids

Area of Science:

• Condensed Matter Physics
• Materials Science
• Computational Chemistry

Background:

• Understanding supercooled liquids and glass properties is crucial.
• Identifying characteristic temperature scales is challenging.
• Formation history impacts glass properties.

Purpose of the Study:

• To systematically identify temperature scales in supercooled liquids.
• To understand the relationship between temperature, particle displacements, and glass properties.
• To define a universal temperature scale (TX) for diverse glass formers.

Main Methods:

• Computer simulations of 11 different glass formers.
• Analysis of particle squared displacements (δr²) between equilibrium and inherent states.
• Statistical analysis of displacement fluctuations and mean values.

Main Results:

• A nonmonotonic dependence of δr² fluctuations on temperature T was observed.
• A crossover temperature (TX) was identified, marking maximal energy landscape heterogeneity.
• TX was extracted for various glass types, unifying their elastic properties.
• Distinct scaling regimes for mean ⟨δr²⟩ were found, with TX as the crossover point (T^0.5 at high T, T^1.3 at low T).

Conclusions:

• The crossover temperature (TX) provides a fundamental scale for supercooled liquids.
• TX unifies the study of diverse glass formers and their elastic properties.
• The identified scaling regimes offer insights into liquid dynamics near the glass transition.