NMR study of filled skutterudite NdOs4P12

We have succeeded in growing the single crystals of NdOs4P12 and investigated the electrical resistivity, magnetic susceptibility and nuclear magnetic resonance (NMR). NdOs4P12 shows metallic behavior in the electric resistivity and undergoes a ferromagnetic transition at 1.15 K. The Knight shift increases upon cooling, similar to the magnetic susceptibility, and little depends on the magnetic field except for below 10 K. Also, the nuclear spin-lattice relaxation rate divided by temperature 1/T1T is largely enhanced with decreasing temperature, implying the significant development of the magnetic fluctuations. 1/T1T is strongly suppressed by the magnetic field, in contrast to the Knight shift. It suggests the coexistence of the ferromagnetic and antiferromagnetic spin fluctuations, similar to the results for NdRu4P12.