Universal nonexponential relaxation: Complex dynamics in simple liquids

Turton, D.A. and Wynne, Klaas (2009) Universal nonexponential relaxation: Complex dynamics in simple liquids. Journal of Chemical Physics, 131 (20). p. 201101. ISSN 0021-9606

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    Abstract

    The dynamics of the noble-gas liquids underlies that of all liquids making them an important prototypical model system. Using optical Kerr-effect spectroscopy we show that for argon, krypton, and xenon, both the librational and diffusional contributions to the spectrum are surprisingly complex. The diffusional relaxation appears as a stretched-exponential, such as widely found in studies of structured (e.g., glass-forming) liquids and as predicted by mode-coupling theory. We show that this behavior is remarkably similar to that measured in water and suggest that it is a fundamental or universal property.