Time-differential perturbed angular correlation method was applied to Ce@C-
82 in order to investigate the electronic properties of the encaged Ce atom
. The nuclear quadrupole frequency of the nuclear spin of the Ce was succes
sfully determined as omega(Q) = 6.5(3)(.)10(7) rad/s, which is much greater
than what has already been estimated for Ce4+ and La3+ in other compounds.
By comparing the present value with the values for the Ce4+ and La3+, it w
as inferred that the valence state of the encaged Ce atom is trivalent.