Thermal expansion coefficient of WRe alloys from first principles
- Author(s)
- Thomas Dengg, Vsevolod Razumovskiy, Lorenz Romaner, Georg Kresse, Peter Puschnig, Juergen Spitaler
- Abstract
We calculate the coefficient of thermal expansion (CTE) in tungsten-rhenium random alloys for Re concentrations between 0% and 50% and for temperatures up to 2400 K by employing the quasiharmonic approximation within the ab initio framework of density functional theory. We treat chemical disorder by the virtual crystal approximation and compute the phonon density of states at two levels of sophistication. While the traditional Debye-Grüneisen (DG) model fails to account for the experimentally observed increase in CTE upon Re addition for concentrations above 10% Re, explicit phonon calculations within density functional perturbation theory lead to an overall good agreement with experiment. Thereby we identify the pronounced phonon softening and anisotropy between transversal and longitudinal modes in W-Re to be responsible for the breakdown of the DG model.
- Organisation(s)
- Computational Materials Physics
- External organisation(s)
- MCL Leoben, Karl-Franzens-Universität Graz
- Journal
- Physical Review B
- Volume
- 96
- No. of pages
- 10
- ISSN
- 2469-9950
- DOI
- https://doi.org/10.1103/PhysRevB.96.035148
- Publication date
- 07-2017
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103025 Quantum mechanics, 103036 Theoretical physics, 103015 Condensed matter, 103009 Solid state physics
- Keywords
- ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials, Condensed Matter Physics
- Portal url
- https://ucris.univie.ac.at/portal/en/publications/thermal-expansion-coefficient-of-wre-alloys-from-first-principles(ad89c236-a36f-4698-983c-ef73e5410be1).html