The frequency-dependent depolarization ratio of the low-frequency Raman scattering of two inorganic systems in their glassy, supercooled, and molten states

A temperature-dependent, low-frequency Raman study for a strong and a fragi le glass-forming liquid is reported in order to elucidate the frequency and temperature sensitivity of the depolarization ratio spectrum, rho(omega,T) . Changes observed in rho(omega,T) are directly reflected on the spectral f eatures of the Raman coupling coefficient, C-alpha beta(omega). Our data pr ovide evidence for polarization dependence of this coefficient, which has b een completely overlooked in studies concerning the experimental determinat ion of C-alpha beta(omega) through a comparison of neutron and reduced Rama n spectra. The current status considering the frequency dependence of the c oupling coefficient is briefly reviewed from the theoretical, experimental, and computer simulation points of view. The experimental data suggest that a reconsideration of the approaches employed should be undertaken. (C) 200 0 American Institute of Physics. [S0021-9606(00)51538-4].