Tetrahedral coordination of Zn ions in molten zinc halides

Abstract

Measurements of the scattering of thermal neutrons from natural samples of molten ZnCl2, ZnBr2, and ZnI2 are reported. The experiments were undertaken on the liquids and amorphous materials diffractometer of the ISIS spallation source at the Rutherford–Appleton laboratory. The data reveal some shortcomings in earlier studies of ZnCl2 but confirm a structural model in which the small Zn2+ ions occupy tetrahedrally coordinated sites in a closely packed anion structure, with strong intermediate range ordering. Features arising from changes in the anion species are identified and temperature-dependent effects are resolved in ZnCl2.