About this Abstract |
| Meeting |
2021 TMS Annual Meeting & Exhibition
|
| Symposium
|
Computational Thermodynamics and Kinetics
|
| Presentation Title |
Contributions of Atom Vibrations to the Heat of Fusion of Germanium |
| Author(s) |
Camille M. Bernal-Choban, Claire N. Saunders, Stefan H. Lohaus, Douglas Abernathy, Brent Fultz |
| On-Site Speaker (Planned) |
Camille M. Bernal-Choban |
| Abstract Scope |
The latent heat of melting of germanium, like silicon, is anomalously high compared to most elements. We measured inelastic neutron scattering from germanium, obtaining atomic vibrational spectra from 300-1373 K. Across the melting temperature, there was a collapse of the higher frequency vibrational modes to significantly lower energies. From the frequency spectra of atom motions, we found that most of the latent heat of melting (4.4 kB/atom) originates from the lower frequencies of atomic motion in the liquid phase. Density functional theory calculations within both a quasi-harmonic (QH) and a temperature-dependent effective potential (TDEP) model were also performed to elucidate the behavior of each mode as Tm was approached. The cubic and quartic anharmonic contributions, in comparison to the quasi-harmonic, are discussed. |
| Proceedings Inclusion? |
Planned: |