Abstract
We have resolved the solid-liquid phase transition of carbon at pressures around 150GPa. High-pressure samples of different temperatures were created by laser-driven shock compression of graphite and varying the initial density from 1.30g/cm3 to 2.25g/cm3. In this way, temperatures from 5700K to 14,500K could be achieved for relatively constant pressure according to hydrodynamic simulations. From measuring the elastic X-ray scattering intensity of vanadium K-alpha radiation at 4.95keVat a scattering angle of 126°, which is very sensitive to the solid-liquid transition, we can determine whether the sample had transitioned to the fluid phase. We find that samples of initial density 1.3g/cm3 and 1.85g/cm3 are liquid in the compressed states, whereas samples close to the ideal graphite crystal density of 2.25g/cm3 remain solid, probably in a diamond-like state.
Original language | English |
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Pages (from-to) | 38-43 |
Number of pages | 6 |
Journal | High Energy Density Physics |
Volume | 14 |
Early online date | 06 Mar 2015 |
DOIs | |
Publication status | Published - Mar 2015 |
Keywords
- Laser-driven shock wave
- Liquid carbon
- Warm dense matter
- X-ray Thomson scattering
ASJC Scopus subject areas
- Nuclear and High Energy Physics
- Radiation