Informace o publikaci
Ab-initio-based analysis of phonon contributions to negative thermal expansion of α-tin
| Autoři | |
|---|---|
| Rok publikování | 2025 |
| Druh | Konferenční abstrakty |
| Fakulta / Pracoviště MU | |
| Citace | |
| Popis | We applied quantum-mechanical calculations to investigate tin’s thermodynamic and dynamic stability in its various allotropic forms. Focusing specifically on the ?-Sn, our results showed a negative thermal expansion within the temperature range from T = 0 K to T = 45 K. No similar phenomenon appears in spectra of other allotropic modifications of tin. That means that the origin of this behaviour is connected to the diamond structure of alpha tin. We investigated the behaviour of the Grüneisen constant of ?-tin in reciprocal space to explain the causes of this phenomenon. There are interesting temperature-dependent contributions of individual phonon modes from different k-points in the reciprocal space. In particular, these contributions are negative at all studied temperatures for the k-points around k-point X (0, 0, 0.5) and positive around k-point ? (0, 0, 0). Negative thermal expansion of a-Sn at low temperatures is thus related to the behaviour of phonons around k-points X, M and N. |