THE STRUCTURE OF MOLTEN ZINC-CHLORIDE AND POTASSIUM-CHLORIDE MIXTURES

The structures of molten mixtures of zinc chloride and potassium chloride have been investigated by pulsed neutron diffraction. Total structure factors have been determined for natural samples of the two pure salts and for mixtures across the composition range using the Liquids and Amorphous Materials Diffractometer at the Rutherford-Appleton Laboratory's ISIS source. The results show that the tetrahedral coordination of anions around zinc ions is present right across the composition range and species of a lower coordination number are not formed. Furthermore, the intermediate-range ordering found in pure zinc chloride is persistent in the mixtures right up to high potassium chloride concentrations. The results are consistent with a recent clustering model, proposed as an explanation for the origin of medium-range ordering in molten salts.