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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
Geometry of slow structural fluctuations in a supercooled binary alloy
Ulf R Pedersen1, Thomas B Schrøder, Jeppe C Dyre
1DNRF Centre Glass and Time, IMFUFA, Department of Sciences, Roskilde University, Postbox 260, DK-4000 Roskilde, Denmark.
Physical Review Letters
|April 7, 2010
Summary
This study reveals that supercooled liquids contain Frank-Kasper clusters, which influence heat capacity changes during cooling. Particle relaxation within these clusters governs the slow dynamics of glass-forming alloys.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Computational Chemistry
Background:
- Understanding the liquid structure of glass-forming alloys is crucial for predicting material properties.
- Supercooled liquids exhibit complex structural arrangements that differ from crystalline states.
Purpose of the Study:
- To investigate the liquid structure of a glass-forming binary alloy.
- To analyze the relationship between structural clusters and thermodynamic properties.
Main Methods:
- Molecular dynamics simulations were employed to model the alloy's behavior.
- The geometrical approach of Frank and Kasper was utilized for structural analysis.
Main Results:
- Extended clusters with crystal-like short-range order were identified in the supercooled liquid.
- A direct correlation was found between heat capacity increases and Frank-Kasper cluster fluctuations.
- Cluster particle relaxation was identified as the dominant factor in the slow dynamics.
Conclusions:
- The findings establish a direct link between the formation of Frank-Kasper clusters and the enhanced heat capacity in supercooled alloys.
- The study highlights the importance of these clusters in governing the relaxation dynamics and glass transition.
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