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Compositional thresholds and anomalies in connection with stiffness transitions in network glasses
M Bauchy1, M Micoulaut, M Boero
1Laboratoire de Physique Théorique de la Matière Condensée, Université Pierre et Marie Curie, 4 Place Jussieu, F-75252 Paris Cedex 05, France.
Physical Review Letters
|May 18, 2013
Summary
First principles molecular dynamics reveal anomalies in amorphous and liquid arsenic-selenium alloys, linking structural and dynamical properties to the Boolchand intermediate phase and rigidity onset in glassy networks.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Computational Chemistry
Background:
- Amorphous and liquid arsenic-selenium (As(x)Se(1-x)) alloys are technologically important materials.
- Understanding their structural and dynamical properties is crucial for predicting material behavior.
- Previous studies have identified an intermediate phase, but its atomic-scale origins remain debated.
Purpose of the Study:
- To investigate the structural and dynamical properties of As(x)Se(1-x) glasses and liquids.
- To correlate observed properties with the Boolchand intermediate phase.
- To elucidate the atomic-scale mechanisms underlying network rigidity onset.
Main Methods:
- First principles molecular dynamics simulations were employed.
- Compositional range studied: 0.2 < x < 0.4.
- Analysis focused on reciprocal space properties and diffusion anomalies.
Main Results:
- Thresholds and anomalies were identified in reciprocal space properties within the studied composition range.
- These findings correlate with the experimental Boolchand intermediate phase.
- Diffusion anomalies were observed in the liquid phase, linked to structural changes.
Conclusions:
- The study links atomic-scale structural and dynamical fingerprints to the Boolchand intermediate phase in As(x)Se(1-x) systems.
- A complex picture of rigidity onset is presented, extending beyond mean-field theories.
- First principles molecular dynamics provides valuable insights into the behavior of these glassy networks.
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