Bulk Aluminum at High Pressure: A First-Principles Study
| Autor: | Michael J. Tambe, Nicola Bonini, Nicola Marzari |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
pseudopotentials
Materials science Phonon phonons FOS: Physical sciences Instability models Condensed Matter::Materials Science Phase (matter) crystals Physics::Atomic and Molecular Clusters Perturbation theory Softening Condensed Matter - Materials Science Condensed matter physics Materials Science (cond-mat.mtrl-sci) simple metals Elasticity (physics) Condensed Matter Physics Electronic Optical and Magnetic Materials Core (optical fiber) al Transverse plane phase-stability Condensed Matter::Strongly Correlated Electrons physics |
| DOI: | 10.48550/arxiv.0710.5122 |
| Popis: | The behavior of metals at high pressure is of great importance to the fields of shock physics, geophysics, astrophysics, and nuclear materials. In order to further understand the properties of metals at high pressures we studied the equation of state of aluminum using first-principles techniques up to 2500 GPa, pressures within reach of the planned L.L.N.L. National Ignition Facility. Our simulations use density-functional theory and density-functional perturbation theory in the generalized gradient approximation at 0K. We found core overlaps to become relevant beyond pressures of 1200 GPa. The equations of state for three phases (fcc, bcc, and hcp) were calculated predicting the fcc-hcp, fcc-bcc, and hcp-bcc transitions to occur at 215 GPa, 307 GPa, and 435 GPa respectively. From the phonon dispersions at increasing pressure, we predict a softening of the lowest transverse acoustic vibrational mode along the [110] direction, which corresponds to a Born instability of the fcc phase at 725 GPa. Comment: 4 pages, 5 figures, accepted to Phys. Rev. B as a Brief Report. This version has update many figures. Moreover we provided updated and more accurate numbers based on further in-depth analyses of potential computational errors |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|