Dielectric relaxation study of ZnCl2 and ZnBr2 solutions in water/DMSO mixtures

Dielectric spectra have been measured for the title systems up to 72 GHz at 20 degrees C with salt concentrations less than or equal to 1 mol/l. The results are described by a superposition of Debye terms. Two terms are sufficient for binary water/DMSO mixtures, while two additional lower frequency ones are required when salt is added. The results for both halides differ only little. The relaxation strengths of a term ascribable to ionic complexes and a term ascribable to water/DMSO (2: 1)complexes vary in opposing sense, demonstrating the competition between those complexes.