Abstract
High-precision measurements of the diamond principal Hugoniot have been made at pressures between 6 and 19 Mbar. Shock velocities were determined with 0.3%-1.1% precision using a velocity interferometer. Impedance-matching analysis, incorporating systematic uncertainties in the equation of state of the quartz standard, was used to determine the Hugoniot with 1.2%-2.7% precision in density. The results are in good agreement with published ab initio calculations, which predict a small negative melt slope along the Hugoniot, but disagree with previous laser-driven shock wave experiments, which had observed a large density increase in the melt region. In the extensive solid-liquid coexistence regime between 6 and 10 Mbar, the present measurements indicate that the mixed phase is a few percent more dense than what would be expected from a simple interpolation between liquid and solid Hugoniots.
Original language | English |
---|---|
Article number | 174102 |
Number of pages | 8 |
Journal | Physical review B |
Volume | 78 |
Issue number | 17 |
DOIs | |
Publication status | Published - Nov 2008 |
Keywords / Materials (for Non-textual outputs)
- SHOCK COMPRESSION
- ELECTRONIC-PROPERTIES
- PHASE-DIAGRAM
- CARBON
- INTERFEROMETER
- PRESSURES
- GRAPHITE
- STATE