Evidence of Long Range Ordering in Molten MgCI2

The low Q rise in the structure factor, ST (Q), of molten MgCl2 observed by Day and McGreevy for Q ≃ 0.3 Å−1 has been confirmed by small angle neutron scattering using the D17 diffractometer at the Institut Laue Langevin. This feature is found to have a possible maximum value at Q ≃ 0.1 Å−1 indicating long range ordering with a correlation length ≃ 60 Å. The results are found to be inconsistent with the possibility of oxygen contamination, so the ordering must be inherent to the liquid structure.