NMR study of spin fluctuations in CeRu4P12

P-31-NMR spectra. Knight shift and nuclear spin-lattice relaxation time T-1 for CeRu4P12 have been measured in the temperature range between 4.2 and 3 30 K. Knight shift is almost temperature independent and nearly equal to ze ro, suggesting that Ce ion seems to be nonmagnetic. Above 150 K, T-1 shows activated-type behavior with the gap energy of 0.078 eV. Since T-1 is longe r than that for LaRu4P12 without 4f-electronsl 4f-spin fluctuation effect o n T-1 is not dominant for CeRu4P12. (C) 2000 Elsevier Science B.V. All righ ts reserved.