A MEASUREMENT OF THE STRUCTURE OF THE SUPERIONIC CONDUCTOR COPPER(I) BROMIDE IN ITS LIQUID-PHASE BY NEUTRON-DIFFRACTION

The scattering of thermal neutrons from samples of molten CuBr has been measured on the D4B liquids diffractometer at the Institut Laue-Langevin, Grenoble. The three partial structure factors and pair distribution functions for this liquid have been determined by isotopic substitution of copper. The investigation reveals a featureless cation-cation partial structure factor and distribution function, and a considerable degree of first-shell penetration by the copper ions. Similarities of thc cation-cation structure to that previously found for CuCl, and evidence of an even greater cation mobility, are consistent with a reduced charge transfer model for these liquids which melt from a superionic phase.