Anomalous Proton Dynamics in Ice at Low Temperatures

Journal Article · Fri Oct 16 00:00:00 EDT 2009 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.103.165901· OSTI ID:21370767

Bove, L E; Klotz, S ^[1]; Paciaroni, A; Sacchetti, F ^[2]

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1. IMPMC, CNRS-UMR 7590, Universite P and M Curie, F-75252 Paris (France)
2. CNR-INFM CRS-Soft, c/o Dipartimento di Fisica, Universita di Perugia, I-06123 Perugia (Italy)

We present incoherent quasielastic neutron scattering measurements on ice Ih (ordinary ice) and Ic (cubic ice) which show the existence of nonharmonic motion of hydrogen at low temperatures, down to 5 K. We show that this dynamics is localized, nonvibrational, and related to the hydrogen disorder since it is absent in ordered ice VIII. A main jump distance of 0.75 A is identified, hence close to the distance between the two possible proton sites along the oxygen-oxygen bond. The dynamics is non-Arrhenius, has a large time rate of 2.7x10{sup 11} s{sup -1}, and affects only a few percent of the total number of hydrogen atoms in the crystal. These results give evidence for the existence of concerted proton tunneling in these ice phases.

• OSTI ID: 21370767
• Journal Information: Physical Review Letters, Vol. 103, Issue 16; Other Information: DOI: 10.1103/PhysRevLett.103.165901; (c) 2009 The American Physical Society; ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
36 MATERIALS SCIENCE
CRYSTALS
HYDROGEN
ICE
NEUTRON REACTIONS
OXYGEN
PROTONS
QUASI-ELASTIC SCATTERING
TUNNEL EFFECT
BARYON REACTIONS
BARYONS
DIRECT REACTIONS
ELEMENTARY PARTICLES
ELEMENTS
FERMIONS
HADRON REACTIONS
HADRONS
NONMETALS
NUCLEAR REACTIONS
NUCLEON REACTIONS
NUCLEONS
QUASI-FREE REACTIONS
SCATTERING