Structural and Collisional Relaxations in Liquids and Supercritical Fluids

Journal Article · Fri Feb 23 00:00:00 EST 2007 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.98.085501· OSTI ID:20957687

Bencivenga, F; Krisch, M; Monaco, G; Sette, F ^[1]; Cunsolo, A ^[2]; Orsingher, L ^[3]; Ruocco, G ^[4]; Vispa, A ^[5]

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1. European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble, Cedex (France)
2. Operative Group in Grenoble c/o ILL, CRS SOFT-INFM-CNR, BP 220, F-38043 Grenoble, Cedex (France)
3. Dipartimento di Fisica, Universita di Trento, 38050 Povo, Trento (Italy)
4. Dipartimento di Fisica, CRS SOFT-INFM-CNR, Universita di Roma 'La Sapienza', Rome (Italy)
5. Dipartimento di Fisica, Universita di Perugia, 06123 Perugia (Italy)

The dynamic structure factor S(Q,{omega}) of both associated (water and ammonia) and simple fluids (nitrogen and neon) has been determined by high-resolution inelastic x-ray scattering in the 2-14 nm{sup -1} momentum transfer range. A line-shape analysis with a generalized hydrodynamic model was used to study the involved relaxation process and to characterize its strength and time scale. We observe that in the liquid phase such a process is governed by rearrangements of intermolecular bonds, whereas in the supercritical region it assumes a collisional nature.

• OSTI ID: 20957687
• Journal Information: Physical Review Letters, Vol. 98, Issue 8; Other Information: DOI: 10.1103/PhysRevLett.98.085501; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AMMONIA
HYDRODYNAMIC MODEL
LIQUIDS
MOMENTUM TRANSFER
NEON
NITROGEN
RELAXATION
STRUCTURE FACTORS
WATER
X-RAY DIFFRACTION