Related Experiment Videos
Amorphous silicon exhibits a glass transition
André Hedler1, Siegfried Ludwig Klaumünzer, Werner Wesch
1Institut für Festkörperphysik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, D-07743 Jena, Germany. Hedler@pinet.uni-jena.de
Nature Materials
|October 27, 2004
Summary
Amorphous silicon exhibits plastic deformation under heavy ion irradiation, providing evidence for a low-density liquid phase. This supports the concept of liquid polymorphism in tetrahedral networks.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Solid State Chemistry
Background:
- Amorphous silicon is a semiconductor with lower density than metallic silicon.
- The amorphous-liquid transition is traditionally viewed as a first-order melting transition.
- Recent studies suggest a liquid-liquid phase transition in silicon, implying a low-density liquid phase.
Purpose of the Study:
- To provide experimental evidence for the existence of a low-density liquid phase in amorphous silicon.
- To investigate the behavior of amorphous silicon under high-energy heavy ion irradiation.
- To explore the phenomenon of liquid polymorphism in tetrahedral networks.
Main Methods:
- Irradiation of amorphous silicon with high-energy heavy ions.
- Observation of plastic deformation in amorphous silicon.
- Analysis of the glass transition temperature.
Main Results:
- Amorphous silicon demonstrated plastic deformation, similar to conventional glasses, under irradiation.
- This plastic deformation provides experimental evidence for the existence of a low-density liquid phase.
- The estimated glass transition temperature for a 10-picosecond timescale is approximately 1,000 K.
Conclusions:
- The findings support the existence of a low-density liquid phase in amorphous silicon.
- The study provides experimental validation for the concept of liquid polymorphism.
- The behavior observed is consistent with general phenomena in tetrahedral network materials.