High-frequency asymptotic shape of the primary relaxation in supercooled liquids

• Published in: Europhysics letters Vol. 39; no. 4; pp. 447 - 452
• Main Authors: Leheny, R. L, Nagel, S. R
• Format: Journal Article
• Language: English
• Published: IOP Publishing 15.08.1997; EDP Sciences
• Subjects: 64.60.-i; 64.70.Pf; 77.22.Gm
• ISSN: 0295-5075; 1286-4854
• DOI: 10.1209/epl/i1997-00375-2

We characterize the high-frequency asymptotic shape of the primary dielectric relaxation for four supercooled liquids: glycerol, propylene carbonate, D-propylene glycol and tricresyl phosphate. Two distinct power laws, with an exact relationship between their exponents, exist above the peak in the imaginary part of the permittivity, $\varepsilon''(\nu)$. The second power law is a robust feature of the spectra, extending at least 13 decades above the peak frequency, for all the liquids. The change with temperature of $\varepsilon''(\nu)$ in this high-frequency region provides direct evidence for a proposed divergence in the static susceptibility in supercooled liquids and suggests that in the simplest analysis the approach to this divergence obeys Curie-Weiss behavior.