Structural markers of the Frenkel line in the proximity of Widom lines

Pruteanu, CG; Proctor, JE; Alderman, OLG; Loveday, JS

Abstract

We have performed a neutron scattering experiment on supercritical
uid nitrogen
at 160 K (1.27 TC) over a wide pressure range (7.8 MPa / 0.260 g/ml to 125 MPa /
0.805 g/ml). This has enabled us to study the process by which nitrogen changes from a fluid that exhibits gas-like behaviour to one that exhibits rigid liquid-like behaviour at
a temperature close to, but above, the critical temperature by crossing the Widom lines followed by the Frenkel line on pressure (density) increase. We find that the Frenkel
line transition is indicated by a transition to a regime of rigid liquid-like behaviour in
which the coordination number remains constant within error, in agreement with our
previous work at 300 K. The Frenkel line transition takes place at approximately the
same density at 160 K and 300 K. The data do not conclusively show an additional
transition at the location of the known Widom lines. We find that behaviour remains
gas-like until the Frenkel line is crossed and our data support the hypothesis that the
Widom line transitions are density increase-driven.

Citation

Pruteanu, C., Proctor, J., Alderman, O., & Loveday, J. (2021). Structural markers of the Frenkel line in the proximity of Widom lines. Journal of Physical Chemistry B, 125(31), 8902-8906. https://doi.org/10.1021/acs.jpcb.1c04690

• Journal Article Type: Article
• Acceptance Date: Jul 16, 2021
• Online Publication Date: Jul 29, 2021
• Publication Date: Jul 29, 2021
• Deposit Date: Aug 24, 2021
• Publicly Available Date: Jul 29, 2022
• Journal: The Journal of Physical Chemistry B (Soft Condensed Matter and Biophysical Chemistry)
• Print ISSN: 1520-6106
• Electronic ISSN: 1520-5207
• Publisher: American Chemical Society
• Volume: 125
• Issue: 31
• Pages: 8902-8906
• DOI: https://doi.org/10.1021/acs.jpcb.1c04690
• Publisher URL: https://doi.org/10.1021/acs.jpcb.1c04690
• Related Public URLs: http://pubs.acs.org/journal/jpcbfk
• Additional Information: Additional Information : ** From Crossref journal articles via Jisc Publications Router **Journal IDs: pissn 1520-6106; eissn 1520-5207 **History: published 12-08-2021; issued 29-07-2021; published_online 29-07-2021; Projects : HECATE