About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Phase Stability, Phase Transformations, and Reactive Phase Formation in Electronic Materials XXV
|
| Presentation Title |
Phonons and Vibrational Entropy of Amorphous Silicon |
| Author(s) |
Ethan Klein, Ann Lin, Brent Fultz |
| On-Site Speaker (Planned) |
Ethan Klein |
| Abstract Scope |
Amorphous silicon (a-Si) continues to be a technologically important electronic material. The local, glass-like atomic structure of a-Si is sensitive to synthesis method and hydrogen impurities, resulting in different thermodynamic stabilities. Here, we investigate the thermodynamic stability of pure and hydrogenated a-Si produced by ball-milling and silane pyrolysis. Using inelastic neutron scattering and calorimetry, we study the temperature dependence of vibrational entropy between 50-600K. With increasing temperature, preliminary results indicate that the phonon density of states (DOS) increases between 30-50meV, where silicon acoustic modes are dominant. This anharmonic behavior is distinctly different from that of crystalline silicon. The contribution of vibrational entropy to the phase stability of a-Si will be evaluated relative to that of crystalline silicon by comparing the temperature dependencies of phonon spectra. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Other, Electronic Materials, Other |