NMR study of magnetic properties in SmRu4P12

Abstract 31 P-NMR spectra and nuclear spin-lattice relaxation time T 1 have been measured in the temperature range between 4.2 and 300 K . NMR spectrum becomes suddenly broad below metal–insulator transition temperature (T MI =16.2 K ) , suggesting that SmRu 4 P 12 shows magnetic phase transition just below T MI . Relaxation rate 1/ T 1 obeys the exponential relation (∝ exp [− Δ E/k B T ]) with Δ E/k B =47 K below T N . The NMR results around T MI are discussed.