skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: FY05 LDRD Final Report Chemical Dynamics At Interfaces

Abstract

At high pressure and temperature, the phase diagram of elemental carbon is poorly known. We present predictions of diamond and BC8 melting lines and their phase boundary in the solid phase, as obtained from first principles calculations. Maxima are found in both melting lines, with a triple point located at {approx} 850 GPa and {approx} 7400 K. Our results show that hot, compressed diamond is a semiconductor which undergoes metalization upon melting. In contrast, in the stability range of BC8, an insulator to metal transition is likely to occur in the solid phase. Close to the diamond/ and BC8/liquid boundaries, molten carbon is a low-coordinated metal retaining some covalent character in its bonding up to extreme pressures. Our results provide constraints on the carbon equation of state, which is of critical importance for devising models of Neptune, Uranus and white dwarf stars, as well as of extra-solar carbon-rich planets.

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
900465
Report Number(s):
UCRL-TR-218833
TRN: US200711%%336
DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUMM MECHANICS, GENERAL PHYSICS; BONDING; CARBON; DIAMONDS; MELTING; PHASE DIAGRAMS; PLANETS; STABILITY; TRIPLE POINT; WHITE DWARF STARS

Citation Formats

Schwegler, E, Ogitsu, T, Bonev, S, Correa, A, Militzer, B, and Galli, G. FY05 LDRD Final Report Chemical Dynamics At Interfaces. United States: N. p., 2006. Web. doi:10.2172/900465.
Schwegler, E, Ogitsu, T, Bonev, S, Correa, A, Militzer, B, & Galli, G. FY05 LDRD Final Report Chemical Dynamics At Interfaces. United States. doi:10.2172/900465.
Schwegler, E, Ogitsu, T, Bonev, S, Correa, A, Militzer, B, and Galli, G. Thu . "FY05 LDRD Final Report Chemical Dynamics At Interfaces". United States. doi:10.2172/900465. https://www.osti.gov/servlets/purl/900465.
@article{osti_900465,
title = {FY05 LDRD Final Report Chemical Dynamics At Interfaces},
author = {Schwegler, E and Ogitsu, T and Bonev, S and Correa, A and Militzer, B and Galli, G},
abstractNote = {At high pressure and temperature, the phase diagram of elemental carbon is poorly known. We present predictions of diamond and BC8 melting lines and their phase boundary in the solid phase, as obtained from first principles calculations. Maxima are found in both melting lines, with a triple point located at {approx} 850 GPa and {approx} 7400 K. Our results show that hot, compressed diamond is a semiconductor which undergoes metalization upon melting. In contrast, in the stability range of BC8, an insulator to metal transition is likely to occur in the solid phase. Close to the diamond/ and BC8/liquid boundaries, molten carbon is a low-coordinated metal retaining some covalent character in its bonding up to extreme pressures. Our results provide constraints on the carbon equation of state, which is of critical importance for devising models of Neptune, Uranus and white dwarf stars, as well as of extra-solar carbon-rich planets.},
doi = {10.2172/900465},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Feb 09 00:00:00 EST 2006},
month = {Thu Feb 09 00:00:00 EST 2006}
}

Technical Report:

Save / Share: