  The 31P-NMR (nuclear magnetic resonance) measurements of the filled
skutterudite SmRu4P12 have been carried out in several applied magnetic fields.
The line width of the 31P-NMR spectrum rapidly increases below the
metal-insulator transition temperature TMI, which indicates the appearance of
an internal field below the temperature. Though no distinct anomaly was
observed below TMI in low fields, a complicated structure was observed between
the Neel temperature TN and TMI (TN < TMI) above 70 kOe. The spin-lattice
relaxation rate 1/T1 is almost independent of temperature above TMI, and
rapidly decreases below TMI. The 1/T1 in low fields decreases monotonously,
whereas the strong suppression of 1/T1 occurs between TN and TMI above 70 kOe.
The structure of the spectra and the suppression of 1/T1 become apparent with
increasing field.
