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Dynamic slowdown and spatial correlations in viscous silica melt: Perspectives from dynamic disorder
Shubham Kumar1, Zhiye Tang1,2, Shinji Saito1,2
1Institute for Molecular Science, Myodaiji, Okazaki, Aichi 444-8585, Japan.
The Journal of Chemical Physics
|January 9, 2026
Summary
Dynamic slowdown in amorphous silica arises from species-dependent atomic constraints and cooperative network rearrangements. This study reveals how dynamic disorder and collective motion govern relaxation in strong glass formers.
Area of Science:
- Condensed matter physics
- Materials science
- Computational chemistry
Background:
- Dynamic slowdown is a key phenomenon in glass-forming liquids.
- Amorphous silica, a strong glass former, exhibits complex relaxation dynamics.
- Understanding the microscopic origins of this slowdown is crucial.
Purpose of the Study:
- Investigate the microscopic origins of dynamic slowdown in amorphous silica.
- Analyze atomic jump dynamics and their relation to structural changes.
- Elucidate the role of species-dependent constraints and cooperative motion.
Main Methods:
- Molecular dynamics simulations were employed.
- Atomic jump dynamics were analyzed.
- Species-resolved point-to-set correlations were calculated.
Main Results:
- Jump statistics deviate from Poisson behavior with decreasing temperature, indicating dynamic disorder.
- Slowdown is species-dependent, with varying neighbor influences for silicon and oxygen.
- Relaxation becomes increasingly slow, intermittent, and cooperative at lower temperatures.
- Relaxation asymmetry between silicon and oxygen is linked to collective motion.
Conclusions:
- A microscopic framework links dynamic disorder, species-dependent constraints, and cooperative correlations.
- These factors provide deeper insight into the slowdown of strong glass-forming networks.
- The study offers a detailed understanding of relaxation mechanisms in amorphous silica.
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