ISSN:
1572-9567
Keywords:
carbon phases
;
diamond
;
electronic effects
;
graphite
;
melting
;
high pressure
;
high temperature
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract A three-phase equation-of-state model, to be used in high-pressure high-density simulations of systems containing carbon, is described for the system graphite-diamond-liquid. The solid phases are represented by cold lattice and thermal energy terms. Simple additivity of the energy terms is assumed and the cold curve is a modified Birch form. Liquid states for diamond and graphite are obtained by a previously described scaling model. The actual Gibbs free energy of the liquid state uses the free energy of these liquids in a mixture model that includes an entropy of mixing and a pressure-dependent strain term. It is noted that the thermal expansion coefficient and the Grüneisen gamma increase faster above 3000 K than the usual approximation for the volume dependence would predict. The result is a phase diagram that fits all available data.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00500721
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