Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8133558 | High Energy Density Physics | 2015 | 6 Pages |
Abstract
We have resolved the solid-liquid phase transition of carbon at pressures around 150 GPa. High-pressure samples of different temperatures were created by laser-driven shock compression of graphite and varying the initial density from 1.30 g/cm3 to 2.25 g/cm3. In this way, temperatures from 5700 K to 14,500 K 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 4.95 keV at 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 1.3 g/cm3 and 1.85 g/cm3 are liquid in the compressed states, whereas samples close to the ideal graphite crystal density of 2.25 g/cm3 remain solid, probably in a diamond-like state.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Astronomy and Astrophysics
Authors
J. Helfrich, D. Kraus, A. Ortner, S. Frydrych, G. Schaumann, N.J. Hartley, G. Gregori, B. Kettle, D. Riley, D.C. Carroll, M.M. Notley, C. Spindloe, M. Roth,