Pressure-temperature phase diagram of elemental carbon

Bundy, F. P.

doi:10.1016/0378-4371(89)90115-5

Cited by 250 publications

(119 citation statements)

References 20 publications

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“…1c. We find that the miscibility temperature of GO even at quite low oxygen concentration (x ≤ 0.05) is around 4000 K, which is rather high and close to the melting point of graphite [31]. The calculated phase diagram clearly demonstrates that it is impossible to get homogeneous GOs by the conventional Hummers methods under the typical temperature for preparing thermally reduced GOs [6,8,9,15,20,21].…”

mentioning

confidence: 69%

Overcoming the Phase Inhomogeneity in Chemically Functionalized Graphene: The Case of Graphene Oxides

Huang

Xiang

et al. 2013

Phys. Rev. Lett.

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mentioning

confidence: 69%

Overcoming the Phase Inhomogeneity in Chemically Functionalized Graphene: The Case of Graphene Oxides

Huang

Xiang

et al. 2013

Phys. Rev. Lett.

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“…The structure of carbon at extreme high pressures and high temperatures (HPHT), such as whether or not it is molten, [1][2][3][4][5][6] is of interest to a wide variety research fields such as physics, 7 astronomy, 8,9 geology, 10 and materials sciences. 11,12 The major hurdles in studying the structure of carbon at extreme pressure-temperature regimes lies in the experimental difficulties in achieving the extreme high pressures and high temperatures simultaneously.…”

mentioning

confidence: 99%

In Situ Observation of Quasimelting of Diamond and Reversible Graphite−Diamond Phase Transformations

Huang¹

2007

Nano Lett.

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Because of technique difficulties in achieving the extreme high-pressure and high-temperature (HPHT) simultaneously, direct observation of the structures of carbon at extreme HPHT conditions has not been possible. Banhart and Ajayan discovered remarkably that carbon onions can act as nanoscopic pressure cells to generate high pressures. By heating carbon onions to ∼700°C and under electron beam irradiation, the graphite-to-diamond transformation was observed in situ by transmission electron microscopy (TEM). However, the highest achievable temperature in a TEM heating holder is less than 1000°C. Here we report that, by using carbon nanotubes as heaters and carbon onions as high-pressure cells, temperatures higher than 2000°C and pressures higher than 40 GPa were achieved simultaneously in carbon onions. At such HPHT conditions and facilitated by electron beam irradiation, the diamond formed in the carbon onion cores frequently changed its shape, size, orientation, and internal structure and moved like a fluid, implying that it was in a quasimelting state. The fluctuation between the solid phase of diamond and the fluid/amorphous phase of diamond-like carbon, and the changes of the shape, size, and orientation of the solid diamond, were attributed to the dynamic crystallization of diamond crystal from the quasimolten state and the dynamic graphite− diamond phase transformations. Our discovery offers unprecedented opportunities to studying the nanostructures of carbon at extreme conditions in situ and at an atomic scale.

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“…Take the box dimensions in the two directions perpendicular to the chain to be approximately equal to the spacing between layers in graphite, 3.37Å, and take the dimension parallel to a chain of n atoms to be 1.28n, where 1.28Å is the typical bond distance. The volume per carbon atom is found to be 14.5Å 3 , giving a density 1.4 g/cm 3 -the same value for all n.…”

Section: Definementioning

confidence: 66%

“…(Our value of β 0 differs slightly from that given by Fahy and Louie, who used a different formula to fit the EOS in the region near zero pressure.) The TFD extrapolation was used above a density of 4.5 g/cm 3 (about 100 GPa). Our room temperature isotherm for the metallic phase is shown in Figure 1.…”

Section: Metallic Solidmentioning

confidence: 99%

SWEIS Annual Review - FY2000

Guerrero¹,

White²,

Bartosch³

et al. 2001

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The PANDA code is used to build a tabular equation of state (EOS) table for carbon. The model includes three solid phases (graphite, diamond, and metallic) and a fluid phase mixture containing three molecular components (C 1 , C 2 , and C 3 ). Separate EOS tables were first constructed for each solid phase and for each molecular species in the fluid phase. Next, a mixture/chemical equilibrium model was used to construct a single multicomponent EOS table for the fluid phase from those for the individual chemical species. Finally, the phase diagram and multiphase EOS were determined from the Helmholtz free energies. The model gives good agreement with experimental thermophysical data, static compression data, known phase boundaries, and shock-wave measurements. This EOS covers a wide range of densities (0 -100 g/cm 3 ) and temperatures (0 -1.0×10 8 K). The new EOS table can be accessed through the SNL-SESAME library as material number 7830.

show abstract

Pressure-temperature phase diagram of elemental carbon

Cited by 250 publications

References 20 publications

Overcoming the Phase Inhomogeneity in Chemically Functionalized Graphene: The Case of Graphene Oxides

Overcoming the Phase Inhomogeneity in Chemically Functionalized Graphene: The Case of Graphene Oxides

In Situ Observation of Quasimelting of Diamond and Reversible Graphite−Diamond Phase Transformations

SWEIS Annual Review - FY2000

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