Thermodynamic behaviour of supercritical matter.

@article{Bolmatov2013ThermodynamicBO,
  title={Thermodynamic behaviour of supercritical matter.},
  author={Dima Bolmatov and Vadim V. Brazhkin and Kostya Trachenko},
  journal={Nature communications},
  year={2013},
  volume={4},
  pages={
          2331
        }
}
Since their discovery in 1822, supercritical fluids have been of enduring interest and have started to be deployed in many important applications. Theoretical understanding of the supercritical state is lacking and is seen to limit further industrial deployment. Here we study thermodynamic properties of the supercritical state and discover that specific heat shows a crossover between two different regimes, an unexpected result in view of currently perceived homogeneity of supercritical state in… 
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References

SHOWING 1-10 OF 68 REFERENCES
Liquidlike behavior of supercritical fluids.
TLDR
The extrapolation of the liquid-vapor-coexistence line in the (P/Pc, T/Tc) plane is identified as the relevant edge between liquidlike and gaslike dynamics, and points to the existence of a connection between structural modifications and transport properties in dense fluids.
Supercritical fluids : fundamentals and applications
Fluids in the approximate range of temperature and pressure 1 to 1.1 and 1 to 2, respectively (referred to critical conditions) are commonly called supercritical. The thermophysical properties in the…
Microscopic relaxation in supercritical and liquid neon
The high frequency behavior of the dynamic structure factor, S(Q,ω), of liquid and supercritical neon is investigated by inelastic x-ray scattering at different temperatures and pressure. The…
Thermodynamic signature of growing amorphous order in glass-forming liquids
That the dynamical properties of a glass-forming liquid at high temperature are different from behaviour in the supercooled state has already been established. Numerical simulations now suggest that…
The Widom line as the crossover between liquid-like and gas-like behaviour in supercritical fluids
According to textbook definitions 1 , there exists no physical observable able to distinguish a liquid from a gas beyond the critical point, and hence only a single fluid phase is defined. There are,…
Entropy-driven liquid–liquid separation in supercooled water
TLDR
A thermodynamic model based on the hypothesis that the anomalous properties of supercooled water may be caused by a critical point that terminates a line of liquid–liquid separation of lower-density and higher-density water is presented.
The phonon theory of liquid thermodynamics
TLDR
A phonon theory of liquids is developed where the perceived difficulty is that interactions in a liquid are both strong and system-specific, implying that the energy strongly depends on the liquid type and that liquid energy can not be calculated in general form.
Two liquid states of matter: a dynamic line on a phase diagram.
TLDR
The new dynamic line is universal: It separates two liquid states at arbitrarily high pressure and temperature and exists in systems where liquid-gas transition and the critical point are absent altogether.
Viscosity of glass-forming liquids
TLDR
This work presents a model offering an improved description of the viscosity–temperature relationship for both inorganic and organic liquids using the same number of parameters as VFT and AM, and casts doubt on the existence of a Kauzmann entropy catastrophe and associated ideal glass transition.
Scaling behavior in the dynamics of a supercooled Lennard-Jones mixture
SummaryWe present the results of a large-scale molecular-dynamics computer simulation of a binary, supercooled Lennard-Jones fluid. At low temperatures and intermediate times the time dependence of…
...
...