Etude par Fabry–Perot des spectres dépolarisés et polarisés du pentachlorobiphenyl liquide entre −54 et +150 °C

A low frequency study (Fabry–Perot) of the polarized and depolarized light scattering spectra of liquid pentachlorobiphenyl is presented from −54 to +150 °C.The relaxation time deduced from the depolarized spectra is measured as a function of temperature and compared with the time obtained by means of other techniques.The weak propagative depolarized doublet is studied at high viscosity, from −54 to +42 °C. The value of the shear rigidity modulus Gx is obtained almost up to the relaxation domain.The Brillouin polarized doublet is also analyzed in the full temperature range and the values of the compressional moduli are calculated.