Liquid sulfur: Local-order evidence of a polymerization transition

The polymerization transition of liquid sulfur has been observed at the microscopic level, through a change in the local order as a function of the temperature. A diffraction measurement using hot source neutrons (λ=0.709 Å) has been performed to determine the pair correlation function. The third peak of this pair correlation function exhibits a drastic drop with increasing temperature that reflects directly the decrease of the concentration of the sulfur atoms in the ${\mathrm{S}}_8$ rings when the rings are progressively breaking into long chains.