High-precision calculation of the equation of state and crystallographic phase stability for aluminum
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
- Quantum Theory Project, Departments of Physics and of Chemistry, University of Florida, Gainesville, Florida 32611 (United States)
High-precision, all-electron, full-potential, local-density approximation (LDA) calculations are used to determine the static lattice equation of state (EOS) and crystalline phase stability of Al to 1 TPa. The low-pressure properties found here are consistent with the results of other nonrelativistic LDA calculations, but differ significantly from the results of relativistic LDA or gradient-dependent approximation calculations. The theoretical 300-K isotherm for fcc Al, obtained by adding phonon effects to the static lattice EOS, is in reasonable agreement with room temperature data up to 220 GPa. The predicted static-lattice phase sequence for Al is fcc{r_arrow}hcp{r_arrow}bcc with the transitions occurring at 205{plus_minus}20 GPa and 565{plus_minus}60 GPa. Estimation of the possible impact of phonons on the fcc{r_arrow}hcp transition produces a fairly firm upper bound of 290 GPa (282) on the room-temperature (zero temperature) fcc{r_arrow}hcp transition pressure. This result suggests that a recent diamond-anvil-cell experiment came very close to achieving the fcc{r_arrow}hcp transition. {copyright} {ital 1996 The American Physical Society.}
- OSTI ID:
- 278722
- Journal Information:
- Physical Review, B: Condensed Matter, Vol. 53, Issue 6; Other Information: PBD: Feb 1996
- Country of Publication:
- United States
- Language:
- English
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