LOW FREQUENCY DYNAMICS IN WATER AND ZnCl2 SOLUTIONS BY QUASI-ELASTIC AND INELASTIC NEUTRON SCATTERING.

We report the results of a study of the low frequency dynamics in H//2O and aqueous solutions of ZnCl//2 as a function of temperature; the results were obtained by quasi-elastic and inelastic neutron scattering using the IN6 time-of-flight spectrometer at I. L. L. , Grenoble. The temperature dependence of the frequency distribution functions for pure H//2O and the saturated ZnCl//2 solution is shown. A discussion about the influence of the choice of the value of the rotational diffusion coefficient D//r on the results from the fit of the quasi-elastic part of the spectrum of the ZnCl//2 solution is presented. We stress the necessity of collateral experimental evidence, such as obtained by depolarized Rayleigh wing scattering.