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Phase-separation perspective on dynamic heterogeneities in glass-forming liquids
C Cammarota1, A Cavagna, I Giardina
1Dipartimento di Fisica, Università di Roma Sapienza, piazzale Aldo Moro 5, 00185, Roma, Italy.
Physical Review Letters
|September 28, 2010
Summary
Dynamic heterogeneities in model glass formers arise from phase separation. A finite surface tension governs this ephemeral regime, even in unconstrained systems.
Area of Science:
- Condensed matter physics
- Statistical mechanics
- Materials science
Background:
- Dynamic heterogeneities are crucial in understanding the behavior of glass-forming materials.
- Previous models often treated these heterogeneities without considering underlying phase separation dynamics.
Purpose of the Study:
- To investigate the role of surface tension in the formation of dynamic heterogeneities.
- To explore the connection between phase separation and dynamic heterogeneity in model glass formers.
Main Methods:
- Simulating a model glass former with constrained overlap to a reference configuration.
- Calculating thermodynamic potentials.
- Analyzing phase separation into regions of varying overlap.
Main Results:
- The system was observed to phase separate into distinct regions based on overlap values.
- Evidence of a Maxwell construction consistent with spinodal decomposition was found.
- A nonzero surface tension was identified as a key factor in dynamic heterogeneity formation.
Conclusions:
- Dynamic heterogeneities in glass formers are linked to an ephemeral phase-separating regime.
- Finite surface tension plays a significant role in the emergence of dynamic heterogeneities.
- These findings suggest a re-evaluation of standard models for unconstrained glass-forming systems.
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