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arXiv · 1805.04664

On the Nature of the Debye-Process in Monohydroxy Alcohols: 5-Methyl-2-Hexanol Investigated by Depolarized Light Scattering and Dielectric Spectroscopy

Jan Gabriel·Florian Pabst·Andreas Helbling·Till Böhmer·Thomas Blochowicz
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Abstract

The slow Debye-like relaxation in the dielectric spectra of monohydroxy alcohols is a matter of long standing debate. In the present work, we probe reorientational dynamics of 5-methyl-2-hexanol with dielectric spectroscopy and depolarized light scattering (DDLS) in the supercooled regime. While in a previous study of a primary alcohol no indication of the Debye peak in the DDLS spectra was found, we now for the first time report clear evidence of a Debye contribution in a monoalcohol in DDLS. A quantitative comparison between the dielectric and DDLS manifestation of the Debye peak reveals that while the dielectric Debye process represents fluctuations in the end-to-end vector dipole moment of the transient chains, its occurrence in DDLS shows a more local signature and is related to residual correlations which occur due to a slight anisotropy of the $α$-relaxation caused by the chain formation.

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Jan Gabriel, Florian Pabst, Andreas Helbling, Till Böhmer, Thomas Blochowicz. 2018-06-15. On the Nature of the Debye-Process in Monohydroxy Alcohols: 5-Methyl-2-Hexanol Investigated by Depolarized Light Scattering and Dielectric Spectroscopy. https://doi.org/10.1103/physrevlett.121.035501

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