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Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
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Understanding the glassy dynamics from melting temperatures in binary glass-forming liquids
Yunhuan Nie1,2, Lijin Wang3, Pengfei Guan1
1Beijing Computational Science Research Center, Beijing 100193, People's Republic of China. pguan@csrc.ac.cn.
Soft Matter
|January 25, 2024
Summary
In soft-core binary liquids, particle dynamics surprisingly reverse with pressure, challenging the notion that small particles always move faster. This dynamic reversal is linked to effective melting temperatures and pressure-dependent behavior.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Statistical Mechanics
Background:
- Small particles are typically expected to move faster than larger ones in mixtures.
- Glass-forming liquids exhibit complex dynamics, including dynamic heterogeneity, which is crucial for understanding their properties.
Purpose of the Study:
- To investigate the counterintuitive dynamic reversal between large and small particles in binary glass-forming liquids under varying pressure.
- To explore the role of particle interactions (soft-core vs. hard-core) and effective melting temperatures in this dynamic reversal.
Main Methods:
- Molecular dynamics simulations were employed to model binary glass-forming liquids with soft-core and hard-core interactions.
- Analysis focused on particle dynamics, structural relaxation, dynamic heterogeneity, and effective melting temperatures as a function of pressure.
Main Results:
- A dynamic reversal was observed in soft-core systems: small particles become slower than large ones at higher pressures.
- This reversal is absent in hard-core systems, highlighting the importance of interaction type.
- Effective melting temperatures of particles correlate with their relaxation dynamics, with higher melting temperatures indicating slower relaxation.
Conclusions:
- The dynamic reversal in soft-core systems is attributed to the non-monotonic pressure dependence of effective melting temperatures.
- Manipulating particle softness can eliminate the dynamic reversal, demonstrating control over particle dynamics.
- The study reveals connections between non-equilibrium glass-formers and equilibrium crystal-formers, particularly regarding melting behavior and dynamics.
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