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Updated: Sep 6, 2025
08:55
Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
8.6K
Is icosahedral short-range order presented in supercooled transition metals?
R M Khusnutdinoff1,2, R R Khairullina1, A A Suslov2
1Department of Physics, Kazan (Volga Region) Federal University, Kazan 420008, Russia.
Summary
Supercooled transition metals exhibit icosahedral short-range order (ISRO). This study reveals ISRO in nickel melts is formed by icosahedral fragments, transforming into fcc/hcp structures during liquid-crystal transitions.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Physical Chemistry
Background:
- Supercooled transition metals lack long-range atomic order but possess specific short-range order.
- Icosahedral short-range order (ISRO), characterized by fivefold symmetry, is linked to deep supercooling capabilities.
- Experimental evidence for ISRO often appears as shoulders and broadenings in the static structure factor S(k).
Purpose of the Study:
- To investigate the local structural characteristics of equilibrium and supercooled nickel melts.
- To elucidate the formation mechanism of ISRO in pure transition metals under varying cooling rates.
- To compare different analytical methods for identifying ISRO in metallic melts.
Main Methods:
- X-ray diffraction experiments on nickel melts.
- Large-scale molecular dynamics (MD) simulations.
- Structural and cluster analysis, including (q4,q6) rotational invariants.
Main Results:
- Strong agreement between experimental X-ray diffraction and MD simulation results for equilibrium nickel melts.
- Nickel melts exhibit short-range order composed of icosahedral fragments and distorted icosahedral clusters.
- The liquid-crystal phase transition in nickel involves the transformation of distorted icosahedral clusters into fcc/hcp-symmetric clusters.
Conclusions:
- The cluster analysis method using (q4,q6) rotational invariants is less effective for identifying distorted ISRO in metal melts compared to other methods.
- The findings provide insights into the atomic arrangement governing supercooling and phase transitions in transition metals.
- ISRO plays a crucial role in the behavior of nickel melts, influencing their stability and transformation pathways.
Keywords:
Voronoi tessellation methodcluster analysiscrystal symmetryicosahedral short-range ordermolecular dynamics simulationsupercooled transition metalsx-ray diffractionMore Related Videos
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