Depolarized light scattering versus optical Kerr effect. II. Insight into the dynamic susceptibility of molecular liquids.
We have previously discussed [J. Chem. Phys. 125, 114502 (2006)] that optical Kerr effect (OKE) and depolarized light scattering (DLS) data of molecular liquids reveal, each in their native domain, the same characteristic signatures of the glass transition dynamics; in particular, the intermediate power law of OKE is equivalent with the excess wing of the frequency-domain data, long since known in dielectric spectroscopy. We now extend the discussion to show that the excess wing is an equally common feature in DLS. We further discuss the time-temperature superposition property of OKE data in relation to our DLS and literature dielectric-spectroscopic results, and the merits of their mode coupling theory analyses. Spectroscopic signatures of a liquid-crystal-forming system (nematogen) are discussed in the same frame.
Brodin
Alexander
A
Experimentalphysik II, Universität Bayreuth, D-95440 Bayreuth, Germany. brodin@ep2.uni-bayreuth.de
Rössler
Ernst A
EA