Palumbo, M;
Fries, SG;
Pasturel, A;
Alfè, D;
(2014)
Anharmonicity, mechanical instability, and thermodynamic properties of the Cr-Re σ-phase.
The Journal of Chemical Physics
, 140
(14)
, Article 144502. 10.1063/1.4869800.
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Abstract
Using density-functional theory in combination with the direct force method and molecular dynamics we investigate the vibrational properties of a binary Cr-Re σ-phase. In the harmonic approximation, we have computed phonon dispersion curves and density of states, evidencing structural and chemical effects. We found that the σ-phase is mechanically unstable in some configurations, for example, when all crystallographic sites are occupied by Re atoms. By using a molecular-dynamics-based method, we have analysed the anharmonicity in the system and found negligible effects (~0.5 kJ/mol) on the Helmholtz energy of the binary Cr-Re σ-phase up to 2000 K (~0.8T(m)). Finally, we show that the vibrational contribution has significant consequences on the disordering of the σ-phase at high temperature.
| Type: | Article |
|---|---|
| Title: | Anharmonicity, mechanical instability, and thermodynamic properties of the Cr-Re σ-phase |
| Location: | United States |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1063/1.4869800 |
| Publisher version: | http://dx.doi.org/10.1063/1.4869800 |
| Language: | English |
| Additional information: | Copyright 2014 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article 'Palumbo, M; Fries, SG; Pasturel, A; Alfè, D; (2014) Anharmonicity, mechanical instability, and thermodynamic properties of the Cr-Re σ-phase. The Journal of Chemical Physics, 140 (14) , Article 144502.' may be found at http://dx.doi.org/10.1063/1.4869800 |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Earth Sciences |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1428994 |
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