Sb-NQR study of filled skutterudite CeFe4Sb12

We report the results of 121,123Sb-nuclear quadrupole resonance (NQR) measurements on CeFe 4 Sb 12 in order to investigate the magnetic properties at low temperatures from a microscopic viewpoint. Above 50 K, the nuclear spin-lattice relaxation time T 1 shows an activated temperature dependence 1 / T 1 ∝ exp ( - Δ / k B T ) with an energy gap Δ / k B = 190 K . On the other hand, below 30 K, 1 / T 1 is proportional to the temperature. This behavior is explained by a pseudogap model, which is suggested to be induced by the effect of the hybridization between Ce 4 f and conduction electrons.