THE STRUCTURAL-PROPERTIES OF LIQUID SULFUR

Neutron diffraction experiments over the momentum transfer range 0<Q<40 AA-1, have been used to investigate the properties of liquid sulphur from 131 degrees C to 230 degrees C, i.e., at conditions around the lambda -transition (Tlambda=159 degrees C). The data have been transformed to give an accurate pair correlation function from which the absolute numbers of atoms in given molecular configurations may be determined. These data seem to be inconsistent with the picture of 'crown'-shaped S 8 molecules below Tlambda. Also it has been found that the diffraction pattern may be analysed as though the liquid was an assembly of roughly spherical molecular units. In this case each unit would contain about six atoms, and the lambda -transition could be related to the percolation limit for the units. It is concluded that a fundamental diffraction analysis of the states of sulphur has thrown new light on long-standing problems.