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Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
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Domain Structural Transition and Structural Heterogeneity in GeO2 Glass Under Densification
LeTien Ha1,2, Pham Huu Kien3,4
1Ceramics and Biomaterials Research Group, Advanced Institute of Materials Science, Ton Duc Thang University, Ho Chi Minh City, Vietnam.
ACS Omega
|November 23, 2020
Summary
GeO2 glass undergoes pressure-induced structural changes, transforming between D4, D5, and D6 domains. This domain transition and coexistence create spatial structural heterogeneity in the glass.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Geochemistry
Background:
- Germanium dioxide (GeO2) glass exhibits complex structural behavior under pressure.
- Understanding its structural transitions is crucial for materials science applications.
Purpose of the Study:
- To investigate the domain structural transition and structural heterogeneity in GeO2 glass.
- To analyze the pressure-dependent structural evolution up to 100 GPa at 300 K.
Main Methods:
- Molecular dynamics (MD) simulation was employed to study GeO2 glass.
- Analysis focused on domain structures (Dx) and their coordination numbers.
Main Results:
- GeO2 glass structure transitions from D4 to D6 via D5 domains with increasing pressure (9-18 GPa).
- Densification involves O-O atom variation, domain merging/splitting, and domain boundary atom exchange.
- Decreased Voronoi polygon volume and coexistence of separate domain structures explain spatial structural heterogeneity.
Conclusions:
- The study reveals pressure-driven domain transitions as the origin of structural heterogeneity in GeO2 glass.
- Detailed insights into pressure-dependent structural evolution and heterogeneity are provided.
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