Abstract
In order to clarify the viscoelastic properties of ZnCl2-MCl (M: Na, K) binary melts, hypersonic velocities have been measured in the temperature range covering about 150 K above the liquidus temperatures of the melts over the composition range of 0 to 50 mol% MCl by means of the Brillouin scattering method. Absorption coefficients of ultrasound were measured for molten ZnCl2 at the frequency range of 5-55 MHz. The hypersonic velocity of ZnCl2 decreases linearly with increasing temperature at the high and the low temperature regions, but at the intermediate temperature region, shows a curvilinear temperature dependence, indicating dispersion of sound propagation.
The dispersion behavior observed is well described in terms of the single relaxation theory. It was found that the relaxation frequency of the binary melts increases steeply with an addition of MCl. This is considered to be due to the depolymerization of the network structures in the melts.
