Collective excitations in a dense dipolar liquid: How important are dipolarons in the polarization relaxation of common dipolar liquids?

Chandra, A and Bagchi, B (1990) Collective excitations in a dense dipolar liquid: How important are dipolarons in the polarization relaxation of common dipolar liquids? In: Journal of Chemical Physics, 92 (11). pp. 6833-6839.

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Abstract

It was recently proposed that collective polarization excitations, called dipolarons in analogy with the plasmons in the Coulomb systems, can exist for a long duration in a dense dipolar liquid. In this article, we present a microscopic analysis of the properties of such collective excitations, both at small and at intermediate wave vectors. The theory predicts the existence of dipolarons at values of the relevant parameters which are in good agreement with the computer simulation of Pollock and Alder. However, the predicted range of the parameter values in which the ``true'' dipolaronic behavior is significant are rather too small to be important in common dipolar liquids like water, acetonitrile or methyl iodide. We find that the microscopic structure, especially the local orientational correlations and also the translational modes of the liquid, play important roles in determining the nature and the lifetime of the dipolaronic modes. Especially, these modes are more likely to occur at intermediate wave numbers if the translational contribution to the polarization relaxation is significant. The consequences of these theoretical predictions in experimental studies are discussed. The Journal of Chemical Physics is copyrighted by The American Institute of Physics.

Item Type:	Journal Article
Publication:	Journal of Chemical Physics
Publisher:	American Institute of Physics
Additional Information:	Copyright of this article belongs to American Institute of Physics
Keywords:	dipolar liquid;polarization;microscopic analysis
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	04 Feb 2008
Last Modified:	19 Sep 2010 04:41
URI:	http://eprints.iisc.ac.in/id/eprint/12634

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