BROAD-BAND ULTRASONIC SPECTROSCOPY ON AQUEOUS-SOLUTIONS OF ZINC(II)CHLORIDE .2. FLUCTUATIONS AND CLUSTERS

Ultrasonic absorption spectra (0.5 to 3000 MHz) of aqueous solutions o f zinc chloride measured at various salt concentrations (0.1 to 0.8 mo lar) are considered in terms of relaxation functions which reflect a c ontinuous distribution of relaxation times. Besides empirical function s particular interest is paid to models which are based on the assumpt ion of concentration fluctuations or of clusters. It is found that the Dissado-Hill function is well suited to represent all measured spectr a with a minimum of adjustable parameters. This function reflects the existence of clusters with internal correlations and also with correla tions in the relaxation behaviour of different clusters.