EXAFS studies of molten ZnCl 2 , RbCl and Rb 2 ZnCl 4

The local structures of molten ZnCl 2 , RbCl and Rb 2 ZnCl 4 are measured with the EXAFS technique. Several models are used to analyse the data, and some structural parameters as well as the radial distribution functions of the nearest-neighbour atoms around Zn or Rb atoms are obtained. The tetrahedra consisting of four Cl atoms around Zn are found to be dominant and stable in molten ZnCl 2 . The skewed behaviour of the radial distribution function for Rb-Cl in molten RbCl is also found, while the local structures around Rb can be regarded as a persistence of the solid state but with strong short-range disorder. In molten Rb 2 ZnCl 4 , a network linked by Zn Cl 4 groups is not found and the nearest-neighbour structures around Rb atoms are more disordered than in molten RbCl. This has also confirmed that the EXAFS method can provide reliable information about the nearest-neighbour atom-atom coordination for some molten salts, which is helpful in specifying the painwise interaction potential.