EVIDENCE FOR A PRONOUNCED LOCAL ORIENTATIONAL ORDER IN THE HIGH-TEMPERATURE PHASE OF C-60

The rotational dynamics in the high temperature phase of C-60 has been investigated experimentally by means of diffuse x-ray and quasielasti c neutron scattering on a single crystal and theoretically by molecula r dynamics simulations. Our results provide evidence for pronounced lo cal orientational order with a correlation length zeta similar to 40 A ngstrom at T = 265 K. The local order seems to be driven by the same n earest neighbor interaction which leads to long range order below T-s but does not possess the symmetry of the low T structure.