Dynamics and Thermodynamics beyond the critical point
Authors: Gorelli F. A., Bryk T., Krisch M., Ruocco G., Santoro M., Scopigno T.
Autors Affiliation: IPCF-CNR, UOS Roma, I-00185 Roma, Italy;
LENS, European Laboratory forNon Linear Spectroscopy, I-50019 Sesto Fiorentino, Italy;
Institute for Condensed Matter Physics, National Academy of Sciences of Ukraine, UA-79011 Lviv, Ukraine, National
Polytechnic University of Lviv, UA-79013 Lviv, Ukraine;
European Synchrotron Research Facility, Grenoble, France;
Dipartimento di Fisica, Università di Roma “La Sapienza”, Roma, Italy;
IFAC-CNR, I-50019 Sesto Fiorentino, Italy.
Abstract: Sudden changes in the dynamical properties of a supercritical fluid model have been found as a function of pressure and temperature (T/Tc52-5 and P/Pc510-103), striving with the notion of a single phase beyond the critical point established by thermodynamics. The sound propagation in the Terahertz frequency region reveals a sharp dynamic crossover between the gas like and the liquid like regimes along several isotherms, which involves, at sufficiently low densities, the interplay between purely acoustic waves and heat waves. Such a crossover allows one to determine a dynamic line in the phase diagram which exhibits a very tight correlation with a number of thermodynamic observables, showing that the supercritical state is remarkably more complex than thought so far.
Journal/Review: SCIENTIFIC REPORTS
Volume: 3 Pages from: 1203 to: 1203
More Information: Two of us, F. A. G. and M. S., have been supported by the European Community (LENS Contract FP7 G.A. No. 228334 LASERLABEUROPE). T. S. has received funding from the European Research Council under the European Community\’s Seventh Framework Program (FP7/2007-2013)/ERC grant Agreement No. 207916.KeyWords: high pressure physics; supercritical fluids; dynamics and thermodynamics; molecular dynamics; Stokes-Einstein relationDOI: 10.1038/srep01203Citations: 65data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2023-12-03References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here