Connection between integrated intensities of depolarized-light-scattering spectra and mesoscopic order in liquids

We have examined the temperature dependence of the integrated intensity of the broad spectral contribution to the depolarized light scattered from liquids in four different experiments analyzed by four different approaches. Although the quantitative results depend upon the method of analysis, in all cases the integrated intensity, which is an equilibrium property, diminishes rapidly with decreasing temperature. This rapid decrease can be understood if the broad spectral line is associated with dipole-induced dipole interactions, which are known to exhibit a cancellation effect and which, in turn, are dependent upon the structure of and degree of order in the liquid. Therefore the integrated intensity of the broad spectral line may be an experimentally determined indicator of the degree of order in liquids and supercooled liquids.