ORIENTATIONAL RELAXATION IN A RANDOM DIPOLAR LATTICE - ROLE OF SPATIAL DENSITY-FLUCTUATIONS IN SUPERCOOLED LIQUIDS

We have carried out a computer ''experiment'' of orientational relaxat ion in a spatially random and orientationally disordered dipolar latti ce (RDL), generated by quenching only the translational motion of a de nse liquid. In the high polarity limit, the orientational relaxation o f the RDL is dramatically different from that of the parent liquid, th e former exhibits a very slow, nonexponential long time decay of the o rientational correlation functions and markedly non-Debye dielectric r elaxation. These results clearly demonstrate the importance of spatial density fluctuations in orientational relaxation.