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Do supercooled liquids freeze by spinodal decomposition?
Lawrence S Bartell1, David T Wu
1Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA.
The Journal of Chemical Physics
|November 13, 2007
Summary
Spinodals are unlikely to occur during the freezing of one-component liquids at moderate supercooling. Ramified solidlike fluctuations in supercooled liquids do not signal spinodal decomposition but influence liquid properties.
Area of Science:
- Physical Chemistry
- Materials Science
- Thermodynamics
Background:
- Spinodal decomposition is a theoretical phase transition relevant to liquid-solid phase changes.
- Previous studies suggested spinodals might occur in freezing at moderate supercooling (T/T_melt=0.6).
- Ramified solidlike fluctuations are observed in simulations of supercooled liquids.
Purpose of the Study:
- To investigate the likelihood of spinodal occurrence in one-component liquid freezing.
- To determine if ramified solidlike fluctuations are precursors to spinodal decomposition.
Main Methods:
- Analysis of heuristic evidence from molecular dynamics simulations of selenium hexafluoride.
- Theoretical arguments based on nucleation kinetics.
Main Results:
- Evidence suggests spinodals do not occur even at significant supercooling (deeper than T/T_melt=0.6).
- Ramified fluctuations do not act as true freezing nuclei but impact liquid properties.
- Supercooled liquids exhibiting these fluctuations do not show spinodal behavior.
Conclusions:
- Spinodal decomposition is unlikely in one-component liquid freezing at moderate supercooling.
- Ramified solidlike fluctuations influence supercooled liquid properties but are not harbingers of spinodal decomposition.
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