NOVEL DYNAMIC BEHAVIOR OF CE-AT-C-82 AT LOW-TEMPERATURE

Dynamic motion of Ce@C-82 in the forms of powder and o-dichlorobenzene solution is discussed based on time-differential perturbed angular co rrelation measurements. The observed angular correlations show the pre sence of two different chemical species of Ce@C-82. The temperature de pendence of the reorientational correlation time abruptly changes at s pecific temperatures, implying the freezing of the molecular rotation. The data at low temperatures reveal that Ce stays at a certain site f or one of the species, whereas for the other the atom has an intramole cular dynamic motion.