Observation of fractional Stokes-Einstein behavior in the simplest hydrogen-bonded liquid

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Fernandez-Alonso, F ; Bermejo, F J ; McLain, S E ; Turner, J F C ; Molaison, J J ; Herwig, K W (2007)

Quasielastic neutron scattering has been used to investigate the single-particle dynamics of hydrogen fluoride across its entire liquid range at ambient pressure. For T>230¿¿K, translational diffusion obeys the celebrated Stokes-Einstein relation, in agreement with nuclear magnetic resonance studies. At lower temperatures, we find significant deviations from the above behavior in the form of a power law with exponent ¿=-0.71±0.05. More striking than the above is a complete breakdown of the Debye-Stokes-Einstein relation for rotational diffusion. Our findings provide the first experimental verification of fractional Stokes-Einstein behavior in a hydrogen-bonded liquid, in agreement with recent computer simulations
  • References (24)
    24 references, page 1 of 3

    1ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX, United Kingdom

    2CSIC-Instituto Estructura de la Materia & Department of Electricity and Electronics, University Basque Country,

    P.O. Box 644, Bilbao 48080, Spain

    3Department of Chemistry, The University of Tennessee, Knoxville, Tennessee 37996-1600, USA

    4Spallation Neutron Source, Oak Ridge National Laboratory, Scarboro Road, Oak Ridge, Tennessee 37830, USA

    (Received 24 October 2006; published 14 February 2007)

    †Electronic address: javier@langran.iem.csic.es [1] A. Einstein, Investigations on the Theory of the Brownian

    Movement (Dover, New York, 1926). [2] J. P. Hansen and I. R. McDonald, Theory of Simple Liquids

    (Academic Press, London, 1986); J. McConnell, The

    (Cambridge Univ. Press, Cambridge, 1987), p. 23. [3] M. D. Ediger, Annu. Rev. Phys. Chem. 51, 99 (2000). [4] S. R. Becker et al., Phys. Rev. Lett. 97, 055901 (2006). [5] U. Ro¨thlisberger et al., J. Chem. Phys. 106, 4658 (1997);

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